COVID-19 testing

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The US CDC's COVID-19 laboratory test kit CDC 2019-nCoV Laboratory Test Kit.jpg
The US CDC's COVID-19 laboratory test kit

COVID-19 testing involves analyzing samples to assess the current or past presence of SARS-CoV-2. The two main branches detect either the presence of the virus or of antibodies produced in response to infection. [1] [2] Tests for viral presence are used to diagnose individual cases and to allow public health authorities to trace and contain outbreaks. Antibody tests instead show whether someone once had the disease. They are less useful for diagnosing current infections because antibodies may not develop for weeks after infection. [3] It is used to assess disease prevalence, which aids the estimation of the infection fatality rate. [4]

Contents

Individual jurisdictions have adopted varied testing protocols, including whom to test, how often to test, analysis protocols, sample collection and the uses of test results. [5] [6] [7] This variation has likely significantly impacted reported statistics, including case and test numbers, case fatality rates and case demographics. [8] [9] [10] [11] Because SARS-CoV-2 transmission occurs days after exposure (and before onset of symptoms) there is an urgent need for frequent surveillance and rapid availability of results. [12]

Test analysis is often performed in automated, high-throughput, medical laboratories by medical laboratory scientists. Alternatively, point-of-care testing can be done in physician's offices and parking lots, workplaces, institutional settings or transit hubs.

Methods

Explanation of the underlying pathophysiology pertaining to diagnosis of COVID-19 Covid-19-Time-Course-05.gif
Explanation of the underlying pathophysiology pertaining to diagnosis of COVID-19

Positive viral tests indicate a current infection, while positive antibody tests indicate a prior infection. [14] Other techniques include a CT scan, checking for elevated body temperature, checking for low blood oxygen level, and the deployment of detection dogs at airports. [15] [16] [17]

Detection of the virus

Reverse transcription polymerase chain reaction

Polymerase chain reaction (PCR) is a process that amplifies (replicates) a small, well-defined segment of DNA many hundreds of thousands of times, creating enough of it for analysis. Test samples are treated with certain chemicals [18] [19] that allow DNA to be extracted. Reverse transcription converts RNA into DNA.

Reverse transcription polymerase chain reaction (RT-PCR) first uses reverse transcription to obtain DNA, followed by PCR to amplify that DNA, creating enough to be analyzed. [19] RT-PCR can thereby detect SARS-CoV-2, which contains only RNA. The RT-PCR process generally requires a few hours. [20]

Real-time PCR (qPCR) [21] provides advantages including automation, higher-throughput and more reliable instrumentation. It has become the preferred method. [22] [23]

The combined technique has been described as real-time RT-PCR [24] or quantitative RT-PCR [25] and is sometimes abbreviated qRT-PCR, [26] rRT-PCR [27] or RT-qPCR, [28] although sometimes RT-PCR or PCR are used. The Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines propose the term RT-qPCR, [29] but not all authors adhere to this.

Average sensitivity for rapid molecular tests were 95.2% (ranging from 68% to 100%) and average specificity was 98.9% (ranging from 92% to 100%) between test results of different company brands and sampling methods. [30]

Samples can be obtained by various methods, including a nasopharyngeal swab, sputum (coughed up material), [31] throat swabs, [32] deep airway material collected via suction catheter [32] or saliva. [33] [34] Drosten et al. remarked that for 2003 SARS, "from a diagnostic point of view, it is important to note that nasal and throat swabs seem less suitable for diagnosis, since these materials contain considerably less viral RNA than sputum, and the virus may escape detection if only these materials are tested." [35]

Sensitivity of clinical samples by RT-PCR is 63% for nasal swab, 32% for pharyngeal swab, 48% for feces, 72–75% for sputum, and 93–95% for bronchoalveolar lavage. [36]

The likelihood of detecting the virus depends on collection method and how much time has passed since infection. According to Drosten tests performed with throat swabs are reliable only in the first week. Thereafter the virus may abandon the throat and multiply in the lungs. In the second week, sputum or deep airways collection is preferred. [32]

Collecting saliva may be as effective as nasal and throat swabs, [33] although this is not certain. [37] [34] Sampling saliva may reduce the risk for health care professionals by eliminating close physical interaction. [38] It is also more comfortable for the patient. [39] Quarantined people can collect their own samples. [38] A saliva test's diagnostic value depends on sample site (deep throat, oral cavity, or salivary glands). [34] Some studies have found that saliva yielded greater sensitivity and consistency when compared with swab samples. [40] [41] [42]

On 15 August 2020, the US FDA granted an emergency use authorization for a saliva test developed at Yale University that gives results in hours. [43] [44]

Viral burden measured in upper respiratory specimens declines after symptom onset. [45]

Isothermal amplification assays

Isothermal nucleic acid amplification tests also amplify the virus's genome. They are faster than PCR because they don't involve repeated heating and cooling cycles. These tests typically detect DNA using fluorescent tags, which are read out with specialized machines. CRISPR gene editing technology was modified to perform the detection: if the CRISPR enzyme attaches to the sequence, it colors a paper strip. The researchers expect the resulting test to be cheap and easy to use in point-of-care settings. [46] [47] The test amplifies RNA directly, without the RNA-to-DNA conversion step of RT-PCR. [48]

Antigen

An antigen is the part of a pathogen that elicits an immune response. Antigen tests look for antigen proteins from the viral surface. In the case of a coronavirus, these are usually proteins from the surface spikes. [49] SARS-CoV-2 antigens can be detected before onset of COVID-19 symptoms (as soon as SARS-CoV-2 virus particles) with more rapid test results, but with less sensitivity than PCR tests for the virus. [50]

Antigen tests may be one way to scale up testing to much greater levels. [49] Isothermal nucleic acid amplification tests can process only one sample at a time per machine. RT-PCR tests are accurate but require too much time, energy and trained personnel to run the tests. [49] "There will never be the ability on a [PCR] test to do 300 million tests a day or to test everybody before they go to work or to school," Deborah Birx, head of the White House Coronavirus Task Force, said on 17 April 2020. "But there might be with the antigen test." [51]

Samples may be collected via nasopharyngeal swab, a swab of the anterior nares, or from saliva. The sample is then exposed to paper strips containing artificial antibodies designed to bind to coronavirus antigens. Antigens bind to the strips and give a visual readout. The process takes less than 30 minutes, can deliver results at point of care, and does not require expensive equipment or extensive training. [49]

Swabs of respiratory viruses often lack enough antigen material to be detectable. [52] This is especially true for asymptomatic patients who have little if any nasal discharge. Viral proteins are not amplified in an antigen test. [49] [53] According to the WHO the sensitivity of similar antigen tests for respiratory diseases like the flu ranges between 34% and 80%. "Based on this information, half or more of COVID-19 infected patients might be missed by such tests, depending on the group of patients tested," the WHO said. While some scientists doubt whether an antigen test can be useful against COVID-19, [53] others have argued that antigen tests are highly sensitive when viral load is high and people are contagious, making them suitable for public health screening. [54] [55] Routine antigen tests can quickly identify when asymptomatic people are contagious, while follow-up PCR can be used if confirmatory diagnosis is needed. [56]

Imaging

Typical visible features on CT initially include bilateral multilobar ground-glass opacities with a peripheral or posterior distribution. [57] COVID-19 can be identified with higher precision using CT than with RT-PCR. [58]

Subpleural dominance, crazy paving, and consolidation may develop as the disease evolves. [57] [59] Chest CT scans and chest x-rays are not recommended for diagnosing COVID-19. Radiologic findings in COVID-19 lack specificity. [60] [57]

Antibody tests

Antibody tester.jpg
Corona antibody test.jpg
Left: Automated analyzer for immunoassays, used, for example, to find SARS-CoV-2 antibodies. Right: Example of quantitative results for SARS-CoV-2 antibody test.

The body responds to a viral infection by producing antibodies that help neutralize the virus. Blood tests (serology tests) can detect the presence of such antibodies. [61] Antibody tests can be used to assess what fraction of a population has once been infected, which can then be used to calculate the disease's mortality rate. [4]

SARS-CoV-2 antibodies' potency and protective period have not been established. [4] [62] Therefore, a positive antibody test may not imply immunity to a future infection. Further, whether mild or asymptomatic infections produce sufficient antibodies for a test to detect has not been established. [63] Antibodies for some diseases persist in the bloodstream for many years, while others fade away. [49]

The most notable antibodies are IgM and IgG. IgM antibodies are generally detectable several days after initial infection, although levels over the course of infection and beyond are not well characterized. [64] IgG antibodies generally become detectable 10–14 days after infection and normally peak around 28 days after infection. [65] [66] This pattern of antibody development seen with other infections, often does not apply to SARS-CoV-2, however, with IgM sometimes occurring after IgG, together with IgG or not occurring at all. [67] Generally, however, median IgM detection occurs 5 days after symptom onset, whereas IgG is detected a median 14 days after symptom onset. [68] IgG levels significantly decline after two or three months. [69]

Average specificity of antigen tests is 99.5%, and average sensitivity is 56.8%, but there is extreme variation in sensitivity results (ranging from 0 to 94%) between test results of different company brands. [30]

Genetic tests verify infection earlier than antibody tests. Only 30% of those with a positive genetic test produced a positive antibody test on day 7 of their infection. [63]

Types

Rapid diagnostic test (RDT)

RDTs typically use a small, portable, positive/negative lateral flow assay that can be executed at point of care. RDTs may process blood samples, saliva samples, or nasal swab fluids. RDTs produce colored lines to indicate positive or negative results. [70]

Enzyme-linked immunosorbent assay (ELISA)

ELISAs can be qualitative or quantitative and generally require a lab. These tests usually use whole blood, plasma, or serum samples. A plate is coated with a viral protein, such as a SARS-CoV-2 spike protein. Samples are incubated with the protein, allowing any antibodies to bind to it. The antibody-protein complex can then be detected with another wash of antibodies that produce a color/fluorescent readout. [70]

Neutralization assay

Neutralization assays assess whether sample antibodies prevent viral infection in test cells. These tests sample blood, plasma or serum. The test cultures cells that allow viral reproduction (e.g., VeroE6 cells). By varying antibody concentrations, researchers can visualize and quantify how many test antibodies block virus replication. [70]

Chemiluminescent immunoassay

Chemiluminescent immunoassays are quantitative lab tests. They sample blood, plasma, or serum. Samples are mixed with a known viral protein, buffer reagents and specific, enzyme-labeled antibodies. The result is luminescent. A chemiluminescent microparticle immunoassay uses magnetic, protein-coated microparticles. Antibodies react to the viral protein, forming a complex. Secondary enzyme-labeled antibodies are added and bind to these complexes. The resulting chemical reaction produces light. The radiance is used to calculate the number of antibodies. This test can identify multiple types of antibodies, including IgG, IgM, and IgA. [70]

Neutralizing vis-à-vis binding antibodies

Most if not all large scale COVID-19 antibody testing looks for binding antibodies only and does not measure the more important neutralizing antibodies (NAb). [71] [72] [73] A NAb is an antibody that defends a cell from an infectious particle by neutralizing its biological effects. Neutralization renders the particle no longer infectious or pathogenic. [74] A binding antibody binds to the pathogen but the pathogen remains infective; the purpose can be to flag the pathogen for destruction by the immune system. [75] It may even enhance infectivity by interacting with receptors on macrophages. [76] Since most COVID-19 antibody tests return a positive result if they find only binding antibodies, these tests cannot indicate that the subject has generated protective NAbs that protect against re-infection. [72] [73]

It is expected that binding antibodies imply the presence of NAbs [73] and for many viral diseases total antibody responses correlate somewhat with NAb responses [77] but this is not established for COVID-19. A study of 175 recovered patients in China who experienced mild symptoms reported that 10 individuals had no detectable NAbs at discharge, or thereafter. How these patients recovered without the help of NAbs and whether they were at risk of re-infection was not addressed. [72] An additional source of uncertainty is that even if NAbs are present, viruses such as HIV can evade NAb responses. [71]

Studies have indicated that NAbs to the original SARS virus (the predecessor to the current SARS-CoV-2) can remain active for two years [78] and are gone after six years. [79] Nevertheless, memory cells including Memory B cells and Memory T cells [80] can last much longer and may have the ability to reduce reinfection severity. [79]

Other tests

Following recovery, many patients no longer have detectable viral RNA in upper respiratory specimens. Among those who do, RNA concentrations three days following recovery are generally below the range in which replication-competent virus has been reliably isolated. [81]

No clear correlation has been described between length of illness and duration of post-recovery shedding of viral RNA in upper respiratory specimens. [82]

Infectivity

Infectivity is indicated by the basic reproduction number (R0, pronounced "R naught") of the disease. [83] SARS-CoV-2 is estimated to have an R0 of 2.2 to 2.5. [84] [85] This means that in a population where all individuals are susceptible to infection, each infected person is expected to infect 2.2 to 2.5 others in the absence of interventions. [86] R0 can vary according factors such as geography, population demographics and density. [87] In New York state R0 was estimated to be 3.4 to 3.8. [88]

On average, an infected person begins showing symptoms five days after infection (the "incubation period") and can infect others beginning two to three days before that. [84] [89] One study reported that 44% of viral transmissions occur within this period. [84] [90] According to the CDC, a significant number of infected people who never show symptoms are nevertheless contagious. [90] [85] In vitro studies have not found replication-competent virus after 9 days from infection. [91] The statistically estimated likelihood of recovering replication-competent virus approaches zero by 10 days. [92]

Infectious virus has not been cultured from urine or reliably cultured from feces; [93] these potential sources pose minimal if any risk of transmitting infection and any risk can be sufficiently mitigated by good hand hygiene.

Patterns and duration of illness and infectivity have not been fully described. However, available data indicate that SARS-CoV-2 RNA shedding in upper respiratory specimens declines after symptom onset. At 10 days recovery of replication-competent virus in viral culture (as a proxy of the presence of infectious virus) approaches zero. Although patients may produce PCR-positive specimens for up to six weeks, [94] it remains unknown whether these samples hold infectious virus. After clinical recovery, many patients do not continue to shed. Among recovered patients with detectable RNA in upper respiratory specimens, concentrations after three days are generally below levels where virus has been reliably cultured. These data were generated from adults across a variety of age groups and with varying severity of illness. Data from children and infants were not available. [91]

History

Timeline of total number of tests in different countries Full-list-cumulative-total-tests-per-million.svg
Timeline of total number of tests in different countries

January

Public Health England announced a test on the 10th, [96] using a real-time RT-PCR (RdRp gene) assay based on oral swabs. [97] The test detected the presence of any type of coronavirus, including specifically identifying SARS-CoV-2. It was rolled out to twelve laboratories across the United Kingdom on 10 February. [98]

Scientists from China first released information on the viral genome on 11 January 2020, [99] [100] sending multiple genomic sequences to GISAID, an indispensable mechanism for sharing influenza genetic sequence data. [101] That day the Malaysian Institute for Medical Research (IMR) produced "primers and probes" specific to a SARS-CoV-2 RT-PCR test. [102] The IMR's materials were used to diagnose Malaysia's first patient on 24 January. [103] BGI Group was one of the first companies to receive emergency use approval from China's National Medical Products Administration for a nucleic acid test. [104]

The German nucleic acid testing protocol was published on the 17th. Another early PCR test was developed by Charité University hospital in Berlin, working with academic collaborators in Europe and Hong Kong, and published on the 23rd. It used rtRT-PCR, and formed the basis of 250,000 kits distributed by the World Health Organization (WHO). [105]

The first case in South Korea was confirmed on 19 January. [106]

In Russia, the first COVID‑19 test was developed by the State Research Center of Virology and Biotechnology VECTOR. Production began on 24 January. [107]

In the US, the Centers for Disease Control and Prevention (CDC) developed its SARS-CoV-2 Real Time PCR Diagnostic Panel. [108] The protocol became available on the 28th. [109] One of three tests in early kits failed due to faulty reagents.[ citation needed ]

February

South Korean company Kogenebiotech's clinical grade, nucleic acid test (PowerChek Coronavirus) was approved by Korea Centers for Disease Control and Prevention (KCDC) on 4 February. [110]

In Wuhan, BGI opened a makeshift 2000-sq-meter emergency detection laboratory named "Huo-Yan" (Chinese :火眼, "Fire Eye") on the 5th. [111] [112] It processed more than 10,000 samples/day. [113] [112] Construction required 5 days. [114] The Wuhan Laboratory was followed by Huo-Yan labs in Shenzhen, Tianjin, Beijing, and Shanghai, in a total of 12 cities across China.[ citation needed ]

On 11 February, the test was approved by the Federal Service for Surveillance in Healthcare in Russia. [115]

In the United States, the CDC refused to let other labs process tests that month, allowing an average of fewer than 100 samples/day to be processed.[ citation needed ] Tests using two components were not determined to be reliable until the 28th, and only then were state and local laboratories permitted to begin testing. [116] The test was approved by the FDA under an EUA.[ citation needed ]

March

Due to limited testing, no countries had reliable data on the prevalence of the virus in their population. [117] Testing variability distorts reported case fatality rates, which were probably overestimated in many countries due to sampling bias. [8] [118] Shortages of reagent and other supplies became a bottleneck for mass testing in the EU and UK [119] and the US. [120] [121]

By 4 March, China reached 50,000 tests per day. [122] Early in March, China reported accuracy problems with its PCR tests. [123] A study examined 1070 samples from 205 Wuhan patients and reported varied sensitivity according to the methods and location of sample collection. Samples from bronchoalveolar lavage fluid specimens returned the highest sensitivity. [124] The authors argued that CT scans showed even higher sensitivity. [125]

US commercial labs began testing in early March. As of the 5th, LabCorp announced nationwide availability of COVID‑19 testing based on RT-PCR. [126] Quest Diagnostics made nationwide testing available as of 9 March. [127] US testing demand grew rapidly, causing backlogs of hundreds of thousands of tests at private US labs. Supplies of swabs and chemical reagents continued strained. [128] On 25 May, the US required each state to take responsibility for meeting its testing needs. [129] In March, the FDA issued EUAs for nucleic acid tests to Hologic (3/16), [130] Abbott Laboratories (3/18), [131] Thermo Fisher Scientific (3/19) [132] Cepheid (3/21) [133] [134] and LabCorp (4/30). [131]

On 12 March, Mayo Clinic announced a nucleic acid test. [135]

On 16 March, the WHO called for ramping up testing programmes as the best way to slow the spread. [136] [137] Several European countries initially conducted more tests than the US. [138] [139] By 19 March, drive-in tests were offered in several large cities. [140]

As of 22 March, according to the president of the Robert Koch Institute, Germany had capacity for 160,000 tests per week. [141] As of 26 March, German Health Minister Jens Spahn estimated that Germany was conducting 200,000 tests per week. [142] Germany has a large medical diagnostics industry, with more than a hundred testing labs that provided the technology and infrastructure to enable rapid increases in testing. Costs are borne by insurance when the test is ordered by a physician. [143] As of the end of March at least 483,295 samples were tested and 33,491 (6.9%) had tested positive. [144]

On 26 March, it was reported that 80% of test kits that Czechia purchased from China gave inaccurate results. [145] [146] Slovakia purchased 1.2 million antibody-based test kits from China that were found to be inaccurate. [147] China accused Czechia and Slovakia of incorrect use of those tests. [148] Ateş Kara of the Turkish Health Ministry said the test kits Turkey purchased from China had a "high error rate". [149] [150]

Spain purchased test kits from Chinese firm Shenzhen Bioeasy Biotechnology Co Ltd, but found that results were unacceptable. The maker explained that the incorrect results may stem from failure to collect samples or use the kits correctly. On 27 March, the Spanish ministry switched to another vendor, Shenzhen Bioeasy. [151]

By 31 March, the United Arab Emirates was testing more of its population per head than any other country. [152] UAE implemented a combination of drive-through sample collection, and a mass-throughput laboratory from Group 42 and BGI. The lab conduced tens of thousands RT-PCR tests per day and was the first to be operational at that scale other than China. [153]

By the month's end, testing had surpassed 200k/week. [154]

April

The FDA gave an EUA for the US' first antibody test on the 2nd. [155] [62]

On 5 April, the U.S. subsidiary of China's BGI Group sent a proposal to the state of California offering to build in California, at cost ($10 million), the world's largest COVID-19 testing site, in 2 weeks, and train Americans to operate it. California's consultants recommended against it, because of the risk of security and commercial competition. [156]

As of 7 April, the World Health Organization (WHO) had accepted two diagnostic tests for procurement under the Emergency Use Listing procedure (EUL). [157]

On 13 April, Health Canada approved a nucleic acid test from Spartan Bioscience. Institutions may "test patients" with a handheld DNA analyzer "and receive results without having to send samples away to a [central] lab". [158] [159]

By the start of April, the United Kingdom was delivering around 10,000 swab tests per day. [160] The British NHS announced that it was piloting a scheme to test suspected cases at home, to remove the risk of one patient infecting others at a hospital or disinfecting an ambulance used to transport a patient. [161]

The UK purchased 3.5 million antibody test kits from China, but in early April 2020 announced these were not usable. [162] [163] On 21 April 2020, the Indian Council of Medical Research (ICMR) advised Indian states to stop using test kits purchased from China after receiving complaints from one state. Rajasthan health minister Raghu Sharma on 21 April said the kits gave only 5.4 percent accurate results. [164]

Antibody survey results found from 2% to 30% positive. [165] On preliminary data, WHO concluded that 2% to 3% of the world population had developed antibodies. [166]

By month end, testing had surpassed 750k/week. [154]

May

A video compilation of free testing sites in California.

In May antibody tests were conducted on 5,603 major league baseball employees and 0.7% tested positive, showing that they had been infected. 70% of those who tested positive had had no symptoms. [167] [168] [169] The US was conducting an average of 2.5 million tests per week for the week ending 17 May. This grew to 3.2 million by 14 June. [170] [171]

Attempts to culture virus from upper respiratory specimens were largely unsuccessful when viral burden is low but detectable (i.e., Ct values[ when defined as? ] higher than 33-35). [91]

On 1 May, Quotient Limited announced the CE Mark for its MosaiQ COVID-19 antibody test, [172] designed as a serological disease screen specific to the Coronavirus. [173] The test has a 100% sensitivity and 99,8% specificity claim. [174] [175]

On 3 May, Roche received an EUA for a selective ELISA serology test. [176] [177]

On 8 May, the FDA granted its first EUA for antigen test: "Sofia 2 SARS Antigen FIA" by Quidel Corp. [178] [56]

The FDA announced on 14 May a review of 15 adverse event reports about the Abbott ID Now device for low sensitivity. [179]

On 21 May, researchers at Ben-Gurion University in Israel reported a one-minute coronavirus test with 90% accuracy, based on the "change in the resonance in the THz spectral range" shown by the coronavirus through THz spectroscopy. [180]

Nearly two million antibody tests imported into Australia and costing $20 million were declared unusable. [181] [182] [183]

In early May Harvard's Global Health Institute estimated that the US needed to test more than 900k per day. [184] [185] Other recommendations ranged up to 23m per day. [186] [187] [188] [189]

As of 24 May, countries that publicised their testing data had typically performed tests equal to 2.6 percent of their population, although no country had tested more than 17.3%. [190]

On 29 May Siemens received an EUA for its anti-spike RBD-targeting serology test that it believes detects neutralizing antibodies. [191]

By month end, testing had surpassed 1.4m/week. [154]

June

In June, researchers announced a nucleic acid diagnostic test using reverse transcription-loop-mediated isothermal amplification (RT-LAMP), an existing technology used in pathogenic microorganism identification, genetically modified ingredients, tumor detection, and embryo sex identification. The test identified virus in samples of serum, urine, saliva, oropharyngeal swabs and nasopharyngeal swabs. Once commercialized the test has the potential to provide rapid (30-45 minute) diagnosis at point of care. The test was 100% selective and highly sensitive, detecting virus at a concentration of .06 fg/ml. [192]

As of 14 June 2020, the percentage testing positive in the US as a whole had fallen below 5%. [193] As of late June, test numbers crossed 600k/day. [170]

November

On 6 November, the U.S. Food and Drug Administration (FDA) authorized the first serology test that detects neutralizing antibodies from recent or prior SARS-CoV-2 infection, which are antibodies that bind to a specific part of a pathogen and have been observed in a laboratory setting to decrease SARS-CoV-2 viral infection of cells. [194] The FDA issued an emergency use authorization (EUA) for the cPass SARS-CoV-2 Neutralization Antibody Detection Kit, which specifically detects this type of antibody. [194] The FDA granted Lucira Health emergency use authorization for the first US at-home rapid molecular diagnostic test. With a prescription from a healthcare provider, consumers can use the test kit to take a nasal swab then perform a 30 minute SARS-CoV-2 detection test at home. [195]

Testing protocols

A sample collection kiosk for COVID-19 testing in India Covid-testing kiosk.jpg
A sample collection kiosk for COVID-19 testing in India

Drive-through testing

In drive-through testing, the person undergoing testing remains in a vehicle while a healthcare professional approaches the vehicle and obtains a sample, all while taking appropriate precautions such as wearing personal protective equipment (PPE). [196] [197] Drive-through centers helped South Korea accelerate its testing program. [198]

Home collection

In Hong Kong test subjects can stay home and receive a specimen tube. They spit into it, return it and later get the result. [199]

Pooled testing

In Israel, researchers at Technion and Rambam Hospital developed a method for testing samples from 64 patients simultaneously, by pooling the samples and only testing further if the combined sample was positive. [200] [201] [202] Pool testing was then adopted in Israel, Germany, Ghana [203] [204] [205] South Korea, [206] Nebraska, [207] China [208] and the Indian states of Uttar Pradesh, [209] West Bengal, [210] Punjab, [211] Chhattisgarh [212] and Maharashtra. [213]

Open source, multiplexed designs released by Origami Assays can test as many as 1122 patient samples using only 93 assays. [214] These balanced designs can be run in small laboratories without robotic liquid handlers.

Multi-tiered testing

One study proposed a rapid immune response assay as a screening test, with a confirmatory nucleic acid test for diagnosis, followed by a rapid antibody test to determine course of action and assess population exposure/herd immunity. [215]

Required volume

Required testing levels are a function of disease spread. The more the cases, the more tests are needed to manage the outbreak. COVID-19 tends to grow exponentially at the beginning of an outbreak, meaning that the number of required tests initially also grows exponentially. If properly targeted testing grows more rapidly than cases, it can be contained.

WHO recommends increasing testing until fewer than 10% are positive in any given jurisdiction. [216]

United States

Number of tests done per day in the US.
Blue: CDC lab
Orange: Public health lab
Gray: Data incomplete due to reporting lag
Not shown: Testing at private labs; total exceeded 100,000 per day by 27 March. Lab-specimens-tested.jpg
Number of tests done per day in the US.
Blue: CDC lab
Orange: Public health lab
Gray: Data incomplete due to reporting lag
Not shown: Testing at private labs; total exceeded 100,000 per day by 27 March.

Economist Paul Romer reported that the US has the technical capacity to scale up to 20 million tests per day, which is his estimate of the scale needed to fully remobilize the economy. [187] The Edmond J. Safra Center for Ethics estimated on 4 April that this capacity could be available by late July. [218] Romer pointed to single-molecule real-time sequencing equipment from Pacific Biosciences [219] [187] and to the Ion Torrent Next-Generation Sequencing equipment from ThermoFisher Scientific. [220] [187] According to Romer, "Recent research papers suggest that any one of these has the potential to scale up to millions of tests per day." This plan requires removing regulatory hurdles. Romer estimated that $100 billion would cover the costs. [187]

Romer also claimed that high test accuracy is not required if tests are administered frequently enough. He ran model simulations in which 7% of the population is tested every day using a test with a 20% false negative rate and a 1% false positive rate. The average person would be tested roughly every two weeks. Those who tested positive would go into quarantine. Romer's simulation indicated that the fraction of the population that is infected at any given time (known as the attack rate) peaks reaches roughly 8% in about thirty days before gradually declining, in most runs reaching zero at 500 days, with cumulative prevalence remaining below 20%. [221]

Available tests

A temporary drive-in testing site for COVID-19 set up with tents in a parking lot BGSU COVID-19 Drive-Thru Testing Site Close Up.jpg
A temporary drive-in testing site for COVID-19 set up with tents in a parking lot

Countries around the world developed tests independently and in partnership with others.

Nucleic acid tests

Tests developed in China, France, Germany, Hong Kong, Japan, the United Kingdom, and the US targeted different parts of the viral genome. WHO adopted the German system for manufacturing kits sent to low-income countries without the resources to develop their own.

PowerChek Coronavirus looks for the "E" gene shared by all beta coronaviruses, and the RdRp gene specific to SARS-CoV-2. [222]

US President Donald Trump displays a COVID-19 testing kit from Abbott Laboratories in March 2020. President Trump Delivers Remarks During a Coronavirus Update Briefing (49720569077).jpg
US President Donald Trump displays a COVID-19 testing kit from Abbott Laboratories in March 2020.

Abbott Laboratories' ID Now nucleic acid test uses isothermal amplification technology. [223] The assay amplifies a unique region of the virus's RdRp gene; the resulting copies are then detected with "fluorescently-labeled molecular beacons". [224] The test kit uses the company's "toaster-size" ID Now device, which is widely deployed in the US. [225] The device can be used in laboratories or in point of care settings, and provides results in 13 minutes or less. [224]

Primerdesign offers its Genesig Real-Time PCR Coronavirus (COVID‑19). Cobas SARS-CoV-2 Qualitative assay runs on the Cobas® 6800/8800 Systems by Roche Molecular Systems. They are offered by the United Nations and other procurement agencies.

Antigen tests

Quidel's "Sofia 2 SARS Antigen FIA" [56] [178] is a lateral flow test that uses monoclonal antibodies to detect the virus's nucleocapsid (N) protein. [226] The result is read out by the company's Sofia 2 device using immunofluorescence. [226] The test is simpler and cheaper but less accurate than nucleic acid tests. It can be deployed in laboratories or at point of care and gives results in 15 minutes. [178] A false negative result occurs if the sample's antigen level is positive but below the test's detection limit, requiring confirmation with a nucleic acid test. [226]

Serology (antibody) tests

Antibodies are usually detectable 14 days after the onset of the infection. Multiple jurisdictions survey their populations using these tests. [227] [228] The test requires a blood draw.[ citation needed ]

Private US labs including Quest Diagnostics and LabCorp offer antibody testing upon request. [229]

Antibody tests are available in various European countries. [230] Quotient Limited developed a CE marked COVID-19 antibody test. [231] [232] [233]

Roche offers a selective ELISA serology test. [234]

A summary review in BMJ has noted that while some "serological tests … might be cheaper and easier to implement at the point of care [than RT-PCR]", and such testing can identify previously infected individuals, "caution is warranted … using serological tests for … epidemiological surveillance". The review called for higher quality studies assessing accuracy with reference to a standard of "RT-PCR performed on at least two consecutive specimens, and, when feasible, includ[ing] viral cultures." [235] [236] CEBM researchers have called for in-hospital 'case definition' to record "CT lung findings and associated blood tests" [237] and for the WHO to produce a "protocol to standardise the use and interpretation of PCR" with continuous re-calibration. [238]

Accuracy

The location of sample collection impact on sensitivity for COVID-19 in 205 Wuhan patients [124]
Samples sourcePositive rate
Bronchoalveolar lavage fluid specimens93% (14/15)
Sputum72% (75/104)
Nasal swabs63% (5/8)
Fibrobronchoscope brush biopsy46% (6/13)
Pharyngeal swabs32% (126/398)
Feces29% (44/153)
Blood1% (3/307)

Accuracy is measured in terms of specificity and selectivity. Test errors can be false positives (the test is positive, but the virus is not present) or false negatives, (the test is negative, but the virus is present). [239]

Sensitivity and specificity

Sensitivity indicates whether the test accurately identifies whether the virus is present. Each test requires a minimum level of viral load in order to produce a positive result. A 90% sensitive test will correctly identify 90% of infections, missing the other 10% (a false negative). Even relatively high sensitivity rates can produce high rates of false negatives in populations with low incidence rates. [239]

Specificity indicates how well-targeted the test is to the virus in question. Highly specific tests pick up only the virus in question. Non-selective tests pick up other viruses as well. A 90% specific test will correctly identify 90% of those who are uninfected, leaving 10% with a false positive result. [239]

Low-specificity tests have a low positive predictive value (PPV) when prevalence is low. For example, suppose incidence is 5%. Testing 100 people at random using a test that has a specificity of 95% would yield on average 5 people who are actually negative who would incorrectly test positive. Since 5% of the subjects actually are positive, another five would also test positive correctly, totaling 10 positive results. Thus, the PPV is 50%, [240] an outcome no different from a coin toss. In this situation retesting those with a positive result increases the PPV to 94.5%, meaning that only 4.5% of the second tests would return the incorrect result, on average less than 1 incorrect result. [241]

Causes of test error

Improper sample collection, exemplified by failure to acquire enough sample and failure to insert a swab deep into the nose. This results in insufficient viral load, one cause of low clinical sensitivity.

The time course of infection also affects accuracy. Samples may be collected before the virus has had a chance to establish itself or after the body has stopped its progress and begun to eliminate it. A May 2020 review of PCR-RT testing found that the median probability of a false-negative result decreased from 100% on day 1, to 67% on day 4. On the day of symptom onset, the probability was 38%, which decreased to 20% 3 days later. [242]

Improper storage for too long a time can cause RNA breakdown and lead to wrong results as viral particles disintegrate. [243]

Improper design and manufacture can yield inaccurate results. Millions of tests made in China were rejected by various countries throughout the period of March 2020 through May 2020.

Test makers typically report the accuracy levels of their tests when seeking approval from authorities. In some jurisdictions, these results are cross-validated by additional assessments. Reported results may not be achieved in clinical settings due to such operational inconsistencies.

PCR-based test

Detection of SARS-CoV-2 by nasal swab over six weeks in patients who experienced mild to moderate illness Fig4-positivity-rate(1).png
Detection of SARS-CoV-2 by nasal swab over six weeks in patients who experienced mild to moderate illness

RT-PCR is the most accurate diagnostic test. [123] It typically has high sensitivity and specificity in a laboratory setting: however, in one study sensitivity dropped to 66–88% clinically. [244]

In one study sensitivity was highest at week one (100%), followed by 89.3%, 66.1%, 32.1%, 5.4% and zero by week six. [245] [246]

A Dutch CDC-led laboratory investigation compared 7 PCR kits. [247] Test kits made by BGI, R-Biopharm AG, BGI, KH Medical and Seegene showed high sensitivity. [248]

High sensitivity kits are recommended to assess people without symptoms, while lower sensitivity tests are adequate when diagnosing symptomatic patients. [247]

The University of Oxford's Centre for Evidence-Based Medicine (CEBM) has pointed to mounting evidence [249] [250] that "a good proportion of 'new' mild cases and people re-testing positives via RT-PCR after quarantine or discharge from hospital are not infectious, but are simply clearing harmless virus particles which their immune system has efficiently dealt with" and have called for "an international effort to standardize and periodically calibrate testing" [251] On 7 September, the UK government issued "guidance for procedures to be implemented in laboratories to provide assurance of positive SARS-CoV-2 RNA results during periods of low prevalence, when there is a reduction in the predictive value of positive test results." [252]

Isothermal nucleic amplification test

One study reported that the ID Now COVID-19 test showed sensitivity of 85.2%. Abbott responded that the issue could have been caused by analysis delays. [253] Another study rejected the test in their clinical setting because of this low sensitivity. [254]

Confirmatory testing

The WHO recommends countries that do not have testing capacity and national laboratories with limited experience on COVID‑19 send their first five positives and the first ten negative COVID‑19 samples to one of the 16 WHO reference laboratories for confirmatory testing. [255] [256] Out of the sixteen reference laboratories, seven are in Asia, five in Europe, two in Africa, one in North America and one in Australia. [257]

National responses

Iceland

Iceland [258] managed the pandemic with aggressive contact tracing, inbound travel restrictions, testing, and quarantining, but with less aggressive lock-downs.

India

Italy

Researchers tested the entire population of , the site of Italy's first COVID‑19 death. They tested about 3,400 people twice, at an interval of ten days. About half the people testing positive had no symptoms. All discovered cases were quarantined. Along with restricting travel to the commune, new infections were completely eliminated. [259]

Japan

Unlike other Asian countries, Japan did not experience a pandemic of SARS or MERS, so the country's PCR testing system was not well developed. [260] [261] Japan preferentially tested patients with severe illness and their close contacts at the beginning. Japan's Novel Coronavirus Expert Meeting chose cluster measures to identify infections clusters. [260] [261] The Expert Meeting analyzed the outbreak from Wuhan and identified conditions leading to clusters (closed spaces, crowded spaces and close-contact), and asked people to avoid them. [261] [262]

In January, contact tracers took action shortly after the first infection was found. Only administrative tests were carried out at first, until insurance began covering PCR tests on 6 March. Private companies began to test, and the test system gradually expanded. [260] [263]

On 3 April, those with positive tests were legally permitted to recuperate at home or in a hotel if they had asymptomatic or mild illness, ending the hospital bed shortage. [264] The first wave (from China) was contained, [265] but a second wave (caused by returnees from Europe and the US) in mid-March led to spreading infection in April. [261] On 7 April, Japan declared a state of emergency, (less strict than a lockdown, because it did not block cities or restrict outings). [261] [264] [266] On 13 May, antigen test kits became covered by insurance, and were combined with a PCR test for diagnosis. [267] [268]

Japan's PCR test count per capita remained far smaller than in some other countries even though its positive test rate was lower. Excess mortality was observed in March. [262] [ failed verification ] [266] [ failed verification ] [269] The Expert Meeting stated, "The Japanese health care system originally carries out pneumonia surveillance, allowing it to detect most of the severely ill patients who develop pneumonia. There are a large number of CT scanners in Japan and they have spread to small hospitals all over the country, so pneumonia patients are rarely missed. In that sense, it meets the same standards as other countries that mainly carry out PCR tests." [262] [269] The group recommended using CT scans data and doctor's findings for diagnosis. [270] [271] On the Diamond Princess cruise ship, many people who initially tested negative later tested positive. Half of coronavirus-positives there who remained mild or asymptomatic had pneumonia findings on CT scans and their CT image showed a frosted glass shadow that is characteristic of infection. [272] [273]

As of 18 July, Japan's daily PCR testing capacity was about 32,000, more than three times the 10,000 cases as of April. When the antigen test is added to it, the number is about 58,000. The number of tests per 1,000 people in the United States is about 27 times that of Japan, the UK is 20 times, Italy is 8 times, and South Korea is twice (as of 26 July). [274] [275] [276] The number of those infected with coronavirus and inpatients has increased in July, but the number of serious cases has not increased. This is thought to be due to the proper testing of those infected in July compared to those in April. In April, the number of tests could not catch up with the increase in the number of infected people, and the test standards were strict, so the test positive rate exceeded 30% at the peak. It means that there were quite a few cases where the those infected was not PCR tested. It is thought that the severe case was preferentially tested though there were a lot of mild cases and asymptomatic carriers mainly in the young during the first wave. In other words, it became possible to grasp the actual situation of infection much better than before by strengthening the testing system. [277] At the end of July, accommodation facilities for mild and asymptomatic carriers became full, and the authorities requested hospitals to prepare beds for the mild. However, it became difficult to treat patients with other illnesses and to maintain the ICU system including the staff due to the occupation of hospital beds by patients with mild symptoms. [278] [279] [280]

Russia

On 27 April, Russia tested 3 million people and had 183,000 positive results. [281] On 28 April Anna Popova, head of Federal Service for Surveillance in Healthcare (Roszdravnadzor) stated that 506 laboratories were testing; that 45% of those who tested positive had no symptoms; that 5% of patients had a severe form; and 40% of infections were from family members. Illness improved from six days to one day after symptoms appeared. Antibody testing was carried out on 3,200 Moscow doctors, finding 20% immunity. [282]

Singapore

With contact tracing, inbound travel restrictions, testing, and quarantining, Singapore arrested the initial spread without complete lockdown. [283]

Slovakia

In late October 2020 Slovakia tested 3.62 million people in a weekend, from a population of 5.4m, representing 67% of the total (or 82% of the adult population), 38,359 tested positive, representing 1.06% of those tested. The government considered the mass test would significantly assist in controlling the virus and avoid a lockdown and may repeat the exercise at a later date. [284]

South Korea

South Korea's broad testing approach helped reduce spread. Testing capacity, largely in private sector labs, was built up over several years by the South Korean government in the early 2000s. [285]

The government exploited the resident registration number (RRN) system. Authorities mobilized young men who were eligible for military service as social service agents, security and public health doctors. Public health doctors were mainly dispatched to public health centers and life treatment centers where mildly ill patients were accommodated. They performed PCR tests and managed mild patients. Social service agents worked in pharmacies to fill staff shortages. Korea's 10k PCR tests per million residents was the world's highest as of 13 April rising to 20k by mid-June. Twenty-seven Korean companies exported test kits worth $48.6 million in March, and were asked to provide test kits or humanitarian assistance by more than 120 countries. Korean authorities set up a treatment center to isolate and manage patients with asymptomatic and minor illnesses in one facility in order to vacate hospital beds for the more severely ill.

Centers were sited mainly at national facilities and corporate training centers. The failure of Korea's MERS quarantine in May 2015 left Korea more prepared for COVID-19 than countries that did not face that pandemic. Then President Park Geun-hye allowed Korean CDC-approved private sector testing for infectious diseases in 2016. Korea already had a system for isolating, testing and treating infectious disease patients separately from others. Patients with respiratory illness but no epidemiological relevance were treated at the National Hospital, and those with epidemiological relevance were treated at selected clinics. [106] [286] [287] [288] [289] [290] [291] [292] [293]

Korea established a large scale drive-through/walk-through" test testing program. However, the most common method was "mobile examination". In Daegu City, 54% of samples were collected by 23 March in home or hospital. Collecting samples door-to-door of avoided the risk of travel by possibly infected patients, but required additional staff. Korea solved the problem by drafting more than 2,700 public insurance doctors. [106] [289] [288]

The government disclosed personal information to the public via KCDC without patient consent. The authorities used digital surveillance to trace possible spread. [286] [289] [290] [292] [293] [294] [295] [296] [297] [298]

Taiwan

Health insurance IDs and national identification card numbers were used to trace contacts. [299] [300] [301] [302]

United States

New York State

New York State's control measures consisted of PCR tests, stay-at-home measures and strengthening the healthcare system. On 29 February before its first case, the state allowed testing at the Wordsworth Center. They managed to convince the CDC to approve tests at state laboratories and the FDA to approve a test kit. As of 13 March the state was conducting more than 1,000 daily tests, growing to 10,000/day on 19 March. In April, the number exceeded 20,000. Many people queued at hospitals to get tested. On 21 March New York City health officials directed medical providers to test only those entering the hospital, for lack of PPE. [292] [303] [304] [305] [306]

USS Theodore Roosevelt

Following an outbreak, 94% of the 4,800 aircraft carrier crew were tested. Roughly 60 percent of the 600-plus sailors who tested positive were asymptomatic. [307] Five infected sailors who completed quarantine subsequently developed flu-like symptoms and again tested positive. [308]

Delayed testing

A shortage of trained medical laboratory scientists, assay reagents, analyzers, transport medium, and PPE coupled with high demand had limited initially limited the availability of testing and led to significantly increased turnaround times.[ citation needed ]

Testing statistics by country

Testing strategies vary by country and over time, [309] with some countries testing very widely, [7] while others have at times focused narrowly on only testing the seriously ill. [310] The country that tests only people showing symptoms will have a higher figure for "% (Confirmed cases as percentage of tested samples or tested cases)" than the country that also tests others. [311] If two countries are alike in every respect, including which people they test, the one that tests more people will have a higher "Confirmed / million people". Studies have also found that countries that test more, relative to the number of deaths, have lower estimated case fatality rates [8] and younger age distributions of cases. [10]

COVID-19 testing statistics by country
LocationDate [lower-alpha 1] TestedUnits [lower-alpha 2] Confirmed
(cases)
%Tested/
million
people
Confirmed/
million
people
Ref.
Flag of Afghanistan.svg Afghanistan 23 November136,808samples45,01732.93,5141,156 [312]
Flag of Albania.svg Albania 19 November165,617samples30,62318.557,84710,696 [313]
Flag of Algeria.svg Algeria 2 November230,553samples58,57425.45,2881,343 [314] [315]
Flag of Andorra.svg Andorra 23 November170,771samples6,3043.72,202,27581,297 [316]
Flag of Antigua and Barbuda.svg Antigua and Barbuda 18 November4,2301393.343,9321,444 [317]
Flag of Argentina.svg Argentina 23 November3,690,837samples1,374,63137.281,33330,292 [318]
Flag of Armenia.svg Armenia 22 November487,088samples126,22425.9165,01742,763 [319]
Flag of Australia (converted).svg Australia 24 November9,775,730samples27,8480.28389,4711,109 [320]
Flag of Austria.svg Austria 25 November2,929,927samples259,2458.8329,10929,120 [321]
Flag of Azerbaijan.svg Azerbaijan 21 November1,592,280samples89,8985.6160,8699,082 [322]
Flag of the Bahamas.svg Bahamas 21 November41,734samples7,41317.8108,22119,223 [323]
Flag of Bahrain.svg Bahrain 25 November2,003,210samples86,1854.31,276,38054,914 [324]
Flag of Bangladesh.svg Bangladesh 22 November2,649,072samples447,34116.916,0842,716 [325]
Flag of Barbados.svg Barbados 22 November44,484samples2590.58154,983902 [326]
Flag of Belarus.svg Belarus 26 November3,158,352samples130,0124.1332,74513,697 [327]
Flag of Belgium (civil).svg Belgium 26 November5,794,351samples567,5329.8503,16649,283 [328]
Flag of Belize.svg Belize 23 November28,827samples5,24918.270,57012,850 [329]
Flag of Bhutan.svg Bhutan 26 November198,422samples3860.19267,523520 [330]
Flag of Bolivia.svg Bolivia 17 November346,623cases143,47341.430,33012,554 [331]
Flag of Bosnia and Herzegovina.svg Bosnia and Herzegovina 18 November383,166samples75,57719.7111,98722,089 [332]
Flag of Botswana.svg Botswana 19 November377,9579,5942.5167,6784,256 [333]
Flag of Brazil.svg Brazil 18 November16,631,388samples5,945,84935.879,14228,294 [334] [335]
Flag of Brunei.svg Brunei 21 November75,2451480.20163,754322 [336]
Flag of Bulgaria.svg Bulgaria 23 November914,723samples121,82013.3131,61517,528 [337]
Flag of Burkina Faso.svg Burkina Faso 17 November67,316samples2,6864.03,220128 [314] [338]
Flag of Burundi.svg Burundi 16 November62,2156411.05,24354 [339]
Flag of Cambodia.svg Cambodia 23 November219,8783060.1413,53119 [340] [341]
Flag of Cameroon.svg Cameroon 16 July135,000samples16,15712.05,086609 [342]
Flag of Canada (Pantone).svg Canada 25 November11,090,768cases347,4663.1292,6739,169 [343]
Flag of Chile.svg Chile 26 November5,174,795samples545,66210.5271,34128,612 [344]
Flag of the People's Republic of China.svg China 31 July160,000,000samples91,4180.06111,16364 [345] [346] [347] [348]
Flag of Colombia.svg Colombia 22 November6,044,047samples1,248,41720.7125,24325,869 [349]
Flag of Costa Rica.svg Costa Rica 20 November366,844samples129,41835.373,37725,886 [350]
Flag of Croatia.svg Croatia 24 November692,048cases108,01415.6169,77626,498 [351]
Flag of Cuba.svg Cuba 21 November1,032,492samples7,8460.7691,156693 [352]
Flag of Cyprus.svg Cyprus [lower-alpha 3] 25 November594,637samples9,4531.6688,82310,950 [353]
Flag of the Czech Republic.svg Czechia 25 November2,953,451samples502,53417.0276,18046,992 [354]
Flag of Denmark.svg Denmark [lower-alpha 4] 25 November7,051,961samples74,2041.11,210,66712,739 [355] [356]
Flag of Djibouti.svg Djibouti 17 November88,9055,6566.496,4476,136 [357]
Flag of Dominica.svg Dominica 21 November5,655cases771.478,9531,075 [358]
Flag of the Dominican Republic.svg Dominican Republic 20 November676,578samples137,77020.462,19612,665 [359]
Flag of the Democratic Republic of the Congo.svg DR Congo 18 November76,66411,91815.5856133 [360]
Flag of Ecuador.svg Ecuador 24 November626,364samples186,43629.836,66310,913 [361]
Flag of Egypt.svg Egypt 18 November709,186samples111,28415.77,0871,112 [360]
Flag of El Salvador.svg El Salvador 19 November524,508samples37,2507.180,8655,743 [362]
Flag of Equatorial Guinea.svg Equatorial Guinea 22 November69,6785,1377.453,2313,924 [363]
Flag of Estonia.svg Estonia 26 November458,690samples10,9552.4345,3058,247 [364]
Flag of Eswatini.svg Eswatini 19 November60,7866,15610.153,4965,418 [365]
Flag of Ethiopia.svg Ethiopia 18 November1,574,870samples103,9286.613,699904 [366]
Flag of the Faroe Islands.svg Faroe Islands 25 November165,822samples5000.303,182,1539,595 [367]
Flag of Fiji.svg Fiji 18 November14,787samples350.2416,49539 [368]
Flag of Finland.svg Finland 26 November1,872,653samples23,1481.2337,8274,176 [369]
Flag of France.svg France [lower-alpha 5] 25 November20,098,815samples2,170,09710.8299,88432,379 [370]
Flag of Gabon.svg Gabon 16 November270,727samples9,0843.48,713292 [371]
Flag of Georgia.svg Georgia [lower-alpha 6] 23 November1,133,765108,6909.6305,03329,242 [372]
Flag of Germany.svg Germany 25 November27,859,242samples993,1283.6332,20211,842 [373]
Flag of Ghana.svg Ghana 19 November578,117samples50,9418.818,6051,639 [374]
Flag of Greece.svg Greece 25 November2,467,145samples97,2883.9229,1089,035 [375]
Flag of Greenland.svg Greenland 25 November12,983samples180.14231,504321 [376]
Flag of Grenada.svg Grenada 18 June5,465samples240.4449,034215 [377]
Flag of Guatemala.svg Guatemala 21 November508,814samples118,62923.329,4746,872 [378]
Flag of Guinea.svg Guinea 18 November164,947cases12,7437.712,560970 [379]
Flag of Haiti.svg Haiti 18 November34,886cases9,21426.43,050805 [380]
Flag of Honduras (darker variant).svg Honduras 18 November253,377samples103,48840.826,42810,794 [381]
Flag of Hungary.svg Hungary 24 November1,528,302samples181,88111.9158,20418,828 [382]
Flag of Iceland.svg Iceland 24 November484,907samples5,3121.11,331,21114,583 [383]
Flag of India.svg India 27 November137,062,749samples9,309,7876.899,3316,747 [384] [385]
Flag of Indonesia.svg Indonesia 26 November3,690,126cases516,75314.013,6871,917 [386] [387]
Flag of Iran.svg Iran 18 November5,626,631samples801,89414.367,6419,640 [388]
Flag of Iraq.svg Iraq 19 November3,202,083samples529,22616.579,60913,157 [389]
Flag of Ireland.svg Ireland 25 November1,911,609samples70,9303.7388,42014,412 [390]
Flag of Israel.svg Israel 25 November5,758,516331,2995.8627,62836,109 [391]
Flag of Italy.svg Italy 26 November21,188,898samples1,509,8757.1351,04525,015 [392]
Flag of Cote d'Ivoire.svg Ivory Coast 17 November205,598samples21,00410.27,794796 [393]
Flag of Jamaica.svg Jamaica 20 November108,576samples10,2409.439,8443,758 [394]
Flag of Japan.svg Japan 17 November3,531,962119,3263.427,998946 [395]
Flag of Jordan.svg Jordan 25 November2,435,340samples198,0218.1228,49618,579 [396]
Flag of Kazakhstan.svg Kazakhstan 7 September2,571,562samples106,3614.1137,8595,702 [397]
Flag of Kenya.svg Kenya 17 November798,585samples71,7299.016,7901,508 [398]
Flag of Kosovo.svg Kosovo 17 November122,377cases30,49524.967,59416,844 [399]
Flag of Kuwait.svg Kuwait 24 November1,062,076samples140,79513.3247,57032,819 [400]
Flag of Kyrgyzstan.svg Kyrgyzstan 3 November426,462samples60,27914.165,3739,240 [401]
Flag of Laos.svg Laos 19 November74,068cases250.0310,3984 [402]
Flag of Latvia.svg Latvia 21 November572,558samples12,7442.2298,2126,638 [403]
Flag of Lebanon.svg Lebanon 22 November1,472,523samples116,4767.9215,74017,065 [404]
Flag of Lesotho.svg Lesotho 22 November25,3902,0868.212,6491,039 [405]
Flag of Liberia.svg Liberia 19 November33,0781,5514.76,520306 [406]
Flag of Libya.svg Libya 17 November375,22875,46520.154,66510,994 [314] [407]
Flag of Lithuania.svg Lithuania 23 November1,267,700samples48,2263.8453,66917,259 [408]
Flag of Luxembourg.svg Luxembourg [lower-alpha 7] 25 November1,325,017samples32,1002.42,116,27551,269 [409]
Flag of Madagascar.svg Madagascar 18 November93,734cases17,34118.53,569660 [410]
Flag of Malawi.svg Malawi 23 November71,970samples6,0098.33,762314 [411]
Flag of Malaysia.svg Malaysia 18 November2,451,545cases50,3902.174,8061,538 [412]
Flag of Maldives.svg Maldives 25 November240,745samples12,8545.3613,40532,751 [413]
Flag of Malta.svg Malta 26 November415,971samples9,4052.3842,79919,055 [414]
Flag of Mauritius.svg Mauritius 22 November289,552samples4940.17228,717390 [415]
Flag of Mexico.svg Mexico 20 November2,277,753cases1,025,96945.017,7057,975 [416]
Flag of Moldova.svg Moldova [lower-alpha 8] 17 November420,228samples90,91221.6159,15334,431 [417]
Flag of Mongolia.svg Mongolia 17 November101,9704340.430,407129 [418]
Flag of Montenegro.svg Montenegro 4 August24,469cases3,36113.738,7655,325 [419]
Flag of Morocco.svg Morocco 22 November3,796,876cases324,9418.6102,8678,803 [420]
Flag of Mozambique.svg Mozambique 19 November216,448samples14,7236.86,925471 [421]
Flag of Myanmar.svg Myanmar 21 November1,004,357samples77,8487.818,4591,431 [422]
Flag of Namibia.svg Namibia 19 November144,428samples13,6629.552,5824,974 [423]
Flag of Nepal.svg Nepal 25 November1,690,509samples226,02613.460,1708,045 [424]
Flag of the Netherlands.svg Netherlands 24 November4,085,548cases493,74412.1234,46528,335 [425]
Flag of New Caledonia.svg New Caledonia 25 November17,273samples320.1963,642118 [426]
Flag of New Zealand.svg New Zealand 24 November1,237,736samples1,6750.14248,363336 [427] [428]
Flag of Nigeria.svg Nigeria 21 November739,216samples66,2289.03,612324 [429]
Flag of North Korea.svg North Korea 19 June922cases00360 [430]
Flag of North Macedonia.svg North Macedonia 19 November303,281samples51,21316.9146,00924,656 [431]
Flag of the Turkish Republic of Northern Cyprus.svg Northern Cyprus [lower-alpha 9] 24 November256,724samples10620.41787,4973,258 [432]
Flag of Norway.svg Norway 25 November2,201,799samples33,7141.5410,2036,281 [433]
Flag of Oman.svg Oman 1 July194,945samples41,19421.141,9478,864 [434]
Flag of Pakistan.svg Pakistan 18 November5,055,382samples365,9277.222,8931,657 [435]
Flag of Palestine.svg Palestine 24 November631,951samples87,83813.9125,09017,387 [436]
Flag of Panama.svg Panama 22 November832,079samples154,78318.6199,21137,057 [437]
Flag of Papua New Guinea.svg Papua New Guinea 22 November31,555samples6121.93,53268 [438]
Flag of Paraguay.svg Paraguay 21 November420,258samples75,85718.158,92110,635 [439]
Flag of Peru.svg Peru 25 November4,982,778samples954,45919.2151,80129,078 [440]
Flag of the Philippines.svg Philippines 21 November5,457,998samples416,8527.654,0504,128 [441]
Flag of Poland.svg Poland 17 November5,480,117cases752,94013.7142,76319,615 [442]
Flag of Portugal.svg Portugal 25 November4,353,234samples274,0116.3423,60626,664 [443]
Flag of Qatar.svg Qatar 25 November1,092,622cases137,85112.6379,24447,847 [444]
Flag of Romania.svg Romania 24 November3,939,421samples430,60510.9203,04622,194 [445]
Flag of Russia.svg Russia 21 November72,429,063samples2,089,3292.9493,55914,237 [446] [447]
Flag of Rwanda.svg Rwanda 22 November607,283samples5,6650.9346,886437 [448]
Flag of Saint Lucia.svg Saint Lucia 19 November14,591samples2031.480,2191,116 [449]
Flag of Saudi Arabia.svg Saudi Arabia 21 November9,218,646samples355,0343.9264,79810,198 [450]
Flag of Senegal.svg Senegal 16 November224,060samples15,8017.114,132997 [451]
Flag of Serbia.svg Serbia 24 November1,660,185cases133,0298.0238,40319,103 [452]
Flag of Singapore.svg Singapore 23 November4,448,110samples58,1901.3779,87810,202 [453] [454]
Flag of Slovakia.svg Slovakia 25 November1,524,523samples109,5047.2279,32520,063 [455]
Flag of Slovenia.svg Slovenia 24 November492,680samples69,30614.1235,27533,096 [456]
Flag of South Africa.svg South Africa 22 November5,290,966cases767,67914.589,21112,944 [457]
Flag of South Korea.svg South Korea 17 November2,774,553cases28,9981.053,657561 [458]
Flag of Spain.svg Spain 19 November21,917,246samples1,617,3557.4468,98834,608 [459] [460]
Flag of Sri Lanka.svg Sri Lanka 23 November736,959samples20,1712.734,008931 [461]
Flag of Sudan.svg Sudan 18 November95,990samples15,04715.72,189343 [360]
Flag of Sweden.svg Sweden 5 July597,850cases72,69312.257,8897,039 [462]
Flag of Switzerland.svg Switzerland [lower-alpha 10] 26 November2,652,082samples313,97811.8308,07036,472 [463]
Flag of the Republic of China.svg Taiwan [lower-alpha 11] 24 November248,625samples6180.2510,53326 [464]
Flag of Tanzania.svg Tanzania 18 November3,88050913.1658.5 [314]
Flag of Thailand.svg Thailand 19 November939,971samples3,8880.4113,53956 [465]
Flag of The Gambia.svg The Gambia 17 November23,348samples3,70515.910,7401,704 [466]
Flag of Togo.svg Togo 18 November137,8122,7522.016,009320 [467]
Flag of Trinidad and Tobago.svg Trinidad and Tobago 21 November35,954cases6,32417.626,3604,636 [468]
Flag of Tunisia.svg Tunisia 19 November427,192samples86,26520.236,1467,299 [469]
Flag of Turkey.svg Turkey 22 November17,245,617samples446,8222.6207,3915,373 [470]
Flag of Uganda.svg Uganda 21 November609,268samples17,9682.913,320393 [471]
Flag of Ukraine.svg Ukraine 21 November4,154,333samples612,66514.798,84014,577 [472]
Flag of the United Arab Emirates.svg United Arab Emirates 25 November16,073,324samples162,6621.01,674,41716,945 [473]
Flag of the United Kingdom.svg United Kingdom 23 November41,533,643samples1,538,7943.7614,89922,782 [474]
Flag of the United States.svg United States 26 November186,027,239samples12,706,1676.8562,03938,389 [475]
Flag of Uruguay.svg Uruguay 22 November399,366samples4,6991.2115,0771,354 [476]
Flag of Uzbekistan.svg Uzbekistan 14 July1,400,000samples13,8720.9941,132408 [477]
Flag of Venezuela.svg Venezuela 21 November2,276,409samples99,4354.478,8043,442 [478]
Flag of Vietnam.svg Vietnam 15 October1,260,799samples1,1240.0912,77111 [479]
Flag of Zambia.svg Zambia 21 November361,046samples17,3944.820,8081,002 [480]
Flag of Zimbabwe.svg Zimbabwe 18 November267,433samples8,9813.417,993604 [481]
  1. Local time.
  2. For some countries it is unclear whether they report samples or cases. One person tested twice is recorded as one case and two samples.
  3. Excluding Northern Cyprus.
  4. The autonomous territories of Greenland and the Faroe Islands are listed separately.
  5. Testing data from 4 May to 12 May is missing because of the transition to the new reporting system SI-DEP.
  6. Excluding Abkhazia and South Ossetia.
  7. Data for residents only.
  8. Excluding Transnistria.
  9. Northern Cyprus is not recognized as a sovereign state by any country except Turkey.
  10. Includes data for Liechtenstein.
  11. Not a United Nations member.

See also

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References

  1. "Coronavirus Disease 2019 (COVID-19)". U.S. Centers for Disease Control and Prevention (CDC). 11 February 2020. Retrieved 9 June 2020.
  2. Kobokovich A, West R, Gronvall G. "Global Progress on COVID-19 Serology-Based Testing". Johns Hopkins Center for Health Security. Retrieved 9 June 2020.
  3. "Test for Past Infection". U.S. Centers for Disease Control and Prevention (CDC). 11 February 2020. Archived from the original on 16 May 2020. Retrieved 19 May 2020. Antibody blood tests, also called antibody tests, check your blood by looking for antibodies, which show if you had a previous infection with the virus. Depending on when someone was infected and the timing of the test, the test may not find antibodies in someone with a current COVID-19 infection.
  4. 1 2 3 Abbasi J (April 2020). "The Promise and Peril of Antibody Testing for COVID-19". JAMA. 323 (19): 1881–83. doi: 10.1001/jama.2020.6170 . PMID   32301958 . Retrieved 20 April 2020.
  5. Brotschi M (7 March 2020). "Bund sucht nicht mehr alle Corona-Infizierten". Der Bund (in German). ISSN   0774-6156 . Retrieved 9 June 2020.
  6. Van Beusekom, Mary (24 March 2020). "Italian doctors note high COVID-19 death rate, urge action". CIDRAP News. Retrieved 9 June 2020.
  7. 1 2 Otmani M (22 March 2020). "COVID-19: First results of the voluntary screening in Iceland". Nordic Life Science. Retrieved 9 June 2020.
  8. 1 2 3 Ward, D. (April 2020) "Sampling Bias: Explaining Wide Variations in COVID-19 Case Fatality Rates". WardEnvironment. doi: 10.13140/RG.2.2.24953.62564/1
  9. Henriques M (2 April 2020). "Coronavirus: Why death and mortality rates differ". BBC News. Retrieved 9 June 2020.
  10. 1 2 Ward D (May 2020). Sampling Bias: Explaining Variations in Age Distributions of COVID-19 Cases. Technical Report (Report). WardEnvironment. doi:10.13140/RG.2.2.27321.19047/2.
  11. "Why More Younger People Are Testing Positive for COVID-19". Time. Retrieved 18 August 2020.
  12. Mina MJ, Parker R, Larremore DB (2020). "Rethinking Covid-19 Test Sensitivity – A Strategy for Containment". The New England Journal of Medicine . doi:10.1056/NEJMp2025631. PMID   32997903. S2CID   222158786.
  13. "Siouxsie Wiles & Toby Morris: What we don't know about Covid-19". The Spinoff. 6 May 2020. Retrieved 6 May 2020.
  14. "Testing for COVID-19". U.S. Centers for Disease Control and Prevention (CDC). 20 May 2020. Archived from the original on 19 May 2020. Retrieved 20 May 2020. Two kinds of tests are available for COVID-19: viral tests and antibody tests.
  15. Tanner, Tari (23 September 2020). "Finland deploys coronavirus-sniffing dogs at main airport". Associated Press . Helsinki . Retrieved 28 October 2020.
  16. Jones, Robert; Guest, Claire; Lindsay, Steve; Kleinschmidt, Immo; Bradley, John; Dewhirst, Sarah; et al. (12 August 2020). "Could bio-detection dogs be used to limit the spread of COVID-19 by travellers?". Journal of Travel Medicine . doi:10.1093/jtm/taaa131. ISSN   1708-8305. PMC   7454791 . PMID   32789466 . Retrieved 28 October 2020.
  17. Jendrny, Paula; Twele, Friederike; Meller, Sebastian; von Köckritz-Blickwede, Maren; Osterhaus, Albertus; Ebbers, Janek; et al. (23 July 2020). "Scent dog identification of samples from COVID-19 patients – a pilot study". BMC Infectious Diseases. 20 (1). 536. doi:10.1186/s12879-020-05281-3. ISSN   1471-2334. PMC   7376324 . PMID   32703188 . Retrieved 28 October 2020.
  18. "RNA Extraction". AssayGenie. Retrieved 7 May 2020.
  19. 1 2 "How is the COVID-19 Virus Detected using Real Time RT-PCR?". IAEA. 27 March 2020. Retrieved 5 May 2020.
  20. "Curetis Group Company Ares Genetics and BGI Group Collaborate to Offer Next-Generation Sequencing and PCR-based Coronavirus (2019-nCoV) Testing in Europe". GlobeNewswire News Room. 30 January 2020. Archived from the original on 31 January 2020. Retrieved 1 February 2020.
  21. Bustin SA, Benes V, Garson JA, Hellemans J, Huggett J, Kubista M, et al. (April 2009). "The MIQE guidelines: minimum information for publication of quantitative real-time PCR experiments". Clinical Chemistry. 55 (4): 611–22. doi: 10.1373/clinchem.2008.112797 . PMID   19246619.
  22. "Real-time reverse transcription PCR (qRT-PCR) and its potential use in clinical diagnosis" (PDF). Clinical Science. 23 September 2005. Retrieved 5 May 2020.
  23. "The Basics: RT-PCR". ThermoFisher Scientific. Retrieved 5 May 2020.
  24. Kang XP, Jiang T, Li YQ, Lin F, Liu H, Chang GH, et al. (June 2010). "A duplex real-time RT-PCR assay for detecting H5N1 avian influenza virus and pandemic H1N1 influenza virus". Virology Journal. 7: 113. doi:10.1186/1743-422X-7-113. PMC   2892456 . PMID   20515509.
  25. Joyce C (2002). Quantitative RT-PCR. A review of current methodologies. Methods Mol. Biol. 193. pp. 83–92. doi:10.1385/1-59259-283-X:083. ISBN   978-1-59259-283-8. PMID   12325527.
  26. Varkonyi-Gasic E, Hellens RP (2010). "qRT-PCR of Small RNAs". Plant Epigenetics. Methods in Molecular Biology. 631. pp. 109–22. doi:10.1007/978-1-60761-646-7_10. ISBN   978-1-60761-645-0. PMID   20204872.
  27. "Accelerated Emergency Use Authorization (Eua) Summary Covid-19 Rt-Pcr Test (Laboratory Corporation of America)". FDA. Retrieved 3 April 2020.
  28. Taylor S, Wakem M, Dijkman G, Alsarraj M, Nguyen M (April 2010). "A practical approach to RT-qPCR-Publishing data that conform to the MIQE guidelines". Methods. 50 (4): S1-5. doi:10.1016/j.ymeth.2010.01.005. PMID   20215014.
  29. Bustin SA, Benes V, Garson JA, Hellemans J, Huggett J, Kubista M, et al. (April 2009). "The MIQE guidelines: minimum information for publication of quantitative real-time PCR experiments". Clinical Chemistry. 55 (4): 611–22. doi: 10.1373/clinchem.2008.112797 . PMID   19246619.
  30. 1 2 Dinnes J, Deeks JJ, Adriano A, Berhane S (2020). "Rapid, point-of-care antigen and molecular-based tests for diagnosis of SARS-CoV-2 infection". Cochrane Database of Systematic Reviews . 8: CD013705. doi:10.1002/14651858.CD013705. PMID   32845525. S2CID   221326336.
  31. "Real-Time RT-PCR Panel for Detection 2019-nCoV". U.S. Centers for Disease Control and Prevention (CDC). 29 January 2020. Archived from the original on 30 January 2020. Retrieved 1 February 2020.
  32. 1 2 3 Drosten C (26 March 2020). "Coronavirus-Update Folge 22" (PDF). NDR. Archived (PDF) from the original on 31 March 2020. Retrieved 2 April 2020.
  33. 1 2 "Here's where things stand on COVID-19 tests in the U.S." ScienceNews. 17 April 2020. Retrieved 6 May 2020.
  34. 1 2 3 Xu R, Cui B, Duan X, Zhang P, Zhou X, Yuan Q (April 2020). "Saliva: potential diagnostic value and transmission of 2019-nCoV". International Journal of Oral Science. 12 (1): 11. doi:10.1038/s41368-020-0080-z. PMC   7162686 . PMID   32300101.
  35. Drosten C, Günther S, Preiser W, van der Werf S, Brodt HR, Becker S, et al. (May 2003). "Identification of a novel coronavirus in patients with severe acute respiratory syndrome". The New England Journal of Medicine. 348 (20): 1967–76. doi: 10.1056/NEJMoa030747 . PMID   12690091.
  36. Ghoshal U, Vasanth S, Tejan N (2020). "A guide to laboratory diagnosis of Corona Virus Disease-19 for the gastroenterologists". Indian Journal of Gastroenterology . 39 (3): 236–242. doi:10.1007/s12664-020-01082-3. PMC   7462729 . PMID   32875524.
  37. "COVID-19 saliva tests: What is the benefit?". Mayo Clinic. 16 April 2020. Retrieved 6 May 2020.
  38. 1 2 "New Rutgers Saliva Test for Coronavirus Gets FDA Approval". Rutgers.edu. 13 April 2020. Retrieved 1 May 2020.
  39. "FDA authorizes Covid-19 saliva test for emergency use". CNN. 14 April 2020. Retrieved 1 May 2020.
  40. Wyllie AL, Fournier J, Casanovas-Massana A, Campbell M, Ko AI (2020). "Saliva or Nasopharyngeal Swab Specimens for Detection of SARS-CoV-2". The New England Journal of Medicine . 383 (13): 1283–86. doi:10.1056/NEJMc2016359. PMC   7484747 . PMID   32857487. S2CID   221358482.
  41. Service RF (2020). "Spit shines for easier coronavirus testing". Science . 369 (6507): 1041–42. doi:10.1126/science.369.6507.1041. PMID   32855317. S2CID   221358939.
  42. "Yale University School of Public Health finds saliva samples promising alternative to nasopharyngeal swab". Merck Manual. 29 April 2020. Retrieved 6 April 2020.
  43. "FDA gives emergency approval to 'game changer' COVID-19 saliva test" . Retrieved 15 August 2020.
  44. "Coronavirus (COVID-19) Update: FDA Issues Emergency Use Authorization to Yale School of Public Health for SalivaDirect, Which Uses a New Method of Saliva Sample Processing". U.S. Food and Drug Administration (FDA) (Press release). 15 August 2020. Retrieved 6 November 2020.
  45. Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced
  46. Zimmer C (5 May 2020). "With Crispr, a Possible Quick Test for the Coronavirus". The New York Times . ISSN   0362-4331 . Retrieved 14 May 2020.
  47. "STOPCovid". stopcovid.science. Retrieved 14 June 2020.
  48. Joung J, Ladha A, Saito M, Segel M, Bruneau R, Huang MW, et al. (May 2020). "Point-of-care testing for COVID-19 using SHERLOCK diagnostics". MedRxiv: 2020.05.04.20091231. doi:10.1101/2020.05.04.20091231. PMC   7273289 . PMID   32511521.
  49. 1 2 3 4 5 6 "Developing Antibodies and Antigens for COVID-19 Diagnostics". Technology Networks. 6 April 2020. Retrieved 30 April 2020.
  50. Guglielmi G (2020). "Fast coronavirus tests: what they can and can't do". Nature (journal) . 585 (7826): 496–498. doi:10.1038/d41586-020-02661-2. PMID   32939084. S2CID   221768935.
  51. "Remarks by President Trump, Vice President Pence, and Members of the Coronavirus Task Force in Press Briefing". Whitehouse.gov. 17 April 2020. Retrieved 30 April 2020.
  52. "NIH launches competition to speed COVID-19 diagnostics". AAAS. 29 April 2020. Retrieved 1 May 2020.
  53. 1 2 "What to know about the three main types of coronavirus tests". CNN. 29 April 2020. Retrieved 30 April 2020.
  54. "Rapid Tests". Rapid Tests.
  55. Shaw, Jonathan (3 August 2020). "Failing the Coronavirus-Testing Test". Harvard Magazine.
  56. 1 2 3 Office of the Commissioner (9 May 2020). "Coronavirus (COVID-19) Update: FDA Authorizes First Antigen Test to Help in the Rapid Detection of the Virus that Causes COVID-19 in Patients". FDA.
  57. 1 2 3 Salehi S, Abedi A, Balakrishnan S, Gholamrezanezhad A (July 2020). "Coronavirus Disease 2019 (COVID-19): A Systematic Review of Imaging Findings in 919 Patients". AJR. American Journal of Roentgenology. 215 (1): 87–93. doi: 10.2214/AJR.20.23034 . PMID   32174129. Known features of COVID-19 on initial CT include bilateral multilobar ground-glass opacification (GGO) with a peripheral or posterior distribution, mainly in the lower lobes and less frequently within the right middle lobe.
  58. Manigandan S, Wu M, Pugazhendhi A, Brindhadevi K (2020). "A systematic review on recent trends in transmission, diagnosis, prevention and imaging features of COVID-19". PROCESS BIOCHEMISTRY . 98: 233–40. doi:10.1016/j.procbio.2020.08.016. PMC   7439988 . PMID   32843849.
  59. Lee EY, Ng MY, Khong PL (April 2020). "COVID-19 pneumonia: what has CT taught us?". The Lancet. Infectious Diseases. 20 (4): 384–85. doi:10.1016/S1473-3099(20)30134-1. PMC   7128449 . PMID   32105641.
  60. "ACR Recommendations for the use of Chest Radiography and Computed Tomography (CT) for Suspected COVID-19 Infection". American College of Radiology. 22 March 2020. Archived from the original on 13 May 2020. Retrieved 20 May 2020.
  61. "The next frontier in coronavirus testing: Identifying the full scope of the pandemic, not just individual infections". STAT. 27 March 2020. Retrieved 30 April 2020.
  62. 1 2 "What Immunity to COVID-19 Really Means". Scientific American. 10 April 2020. Archived from the original on 28 April 2020.
  63. 1 2 Deeks JJ, Dinnes J, Takwoingi Y, Davenport C, Spijker R, Taylor-Phillips S, et al. (June 2020). "Antibody tests for identification of current and past infection with SARS-CoV-2". The Cochrane Database of Systematic Reviews. 6: CD013652. doi:10.1002/14651858.CD013652. PMC   7387103 . PMID   32584464. S2CID   220061130.
  64. "Cellex Emergency Use Authorization". FDA. 1 April 2020. Retrieved 10 April 2020.
  65. "Will an Antibody Test Allow Us to Go Back to School or Work?". The New York Times . 10 April 2020. Retrieved 15 April 2020.
  66. "Mount Sinai Emergency Use Authorization". FDA. 15 April 2020. Retrieved 18 April 2020.
  67. Bauer G (2020). "The variability of the serological response to SARS-corona virus-2: Potential resolution of ambiguity through determination of avidity (functional affinity)". Journal of Medical Virology . doi:10.1002/jmv.26262. PMC   7361859 . PMID   32633840.
  68. Ravi N, Cortade DL, Ng E, Wang SX (2020). "Diagnostics for SARS-CoV-2 detection: A comprehensive review of the FDA-EUA COVID-19 testing landscape". Biosensors and Bioelectronics . 165: 112454. doi:10.1016/j.bios.2020.112454. PMC   7368663 . PMID   32729549.
  69. Goudouris ES (2020). "Laboratory diagnosis of COVID-19". JORNAL DE PEDIATRIA . doi:10.1016/j.jped.2020.08.001. PMC   7456621 . PMID   32882235.
  70. 1 2 3 4 "Global Progress on COVID-19 Serology-Based Testing". Johns Hopkins Center for Health Security. Retrieved 14 June 2020.
  71. 1 2 "A SARS-CoV-2 surrogate virus neutralization test (sVNT) based on antibody-mediated blockage of ACE2-spike (RBD) protein-protein interaction". Research Square. 23 April 2020. Retrieved 28 April 2020.
  72. 1 2 3 "Will antibody tests for the coronavirus really change everything?". Nature. 18 April 2020. Retrieved 20 April 2020.
  73. 1 2 3 "Q&A on COVID-19 Antibody Tests". factcheck.org. 27 April 2020. Retrieved 28 April 2020.
  74. "Neutralising antibody". Biology-Online. 2008. Retrieved 4 July 2009.
  75. Schmaljohn AL (July 2013). "Protective antiviral antibodies that lack neutralizing activity: precedents and evolution of concepts". Current HIV Research. 11 (5): 345–53. doi:10.2174/1570162x113116660057. PMID   24191933.
  76. "Virus neutralization by antibodies". Virology Blog. 24 July 2009. Retrieved 29 April 2020.
  77. "expert reaction to announcement by Roche of its new serology test for COVID-19 antibodies". Science Media Centre. 17 April 2020. Retrieved 28 April 2020.
  78. Cao WC, Liu W, Zhang PH, Zhang F, Richardus JH (September 2007). "Disappearance of antibodies to SARS-associated coronavirus after recovery". The New England Journal of Medicine. NEJM. 357 (11): 1162–63. doi:10.1056/NEJMc070348. PMID   17855683.
  79. 1 2 "Lack of Peripheral Memory B Cell Responses in Recovered Patients with Severe Acute Respiratory Syndrome: A Six-Year Follow-Up Study" (PDF). Journal of Immunology. 19 April 2011. Retrieved 1 May 2020.
  80. Leslie M (May 2020). "T cells found in coronavirus patients 'bode well' for long-term immunity". Science. 368 (6493): 809–10. Bibcode:2020Sci...368..809L. doi: 10.1126/science.368.6493.809 . PMID   32439770. S2CID   218834495.
  81. Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced
  82. Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced
  83. "What Is R0? Gauging Contagious Infections". Healthline.
  84. 1 2 3 He X, Lau EH, Wu P, Deng X, Wang J, Hao X, et al. (May 2020). "Temporal dynamics in viral shedding and transmissibility of COVID-19". Nature Medicine. 26 (5): 672–75. doi: 10.1038/s41591-020-0869-5 . PMID   32296168.
  85. 1 2 "Coronavirus Disease 2019 (COVID-19)". U.S. Centers for Disease Control and Prevention (CDC). 29 April 2020. Retrieved 23 May 2020.
  86. Fraser C, Donnelly CA, Cauchemez S, Hanage WP, Van Kerkhove MD, Hollingsworth TD, et al. (June 2009). "Pandemic potential of a strain of influenza A (H1N1): early findings". Science. 324 (5934): 1557–61. Bibcode:2009Sci...324.1557F. doi:10.1126/science.1176062. PMC   3735127 . PMID   19433588.Free text
  87. "COVID-19 Infections Tracker". COVID-19 Projections Using Machine Learning. Retrieved 11 May 2020.
  88. "About covid19-projections.com". COVID-19 Projections Using Machine Learning. Retrieved 11 May 2020.
  89. "People with COVID-19 may be infectious days before symptoms: study". medicalxpress.com. 15 April 2020. Retrieved 11 May 2020.
  90. 1 2 "50 Percent of People with COVID-19 Aren't Aware They Have Virus". Healthline. 24 April 2020. Retrieved 11 May 2020.
  91. 1 2 3 "Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19". U.S. Centers for Disease Control and Prevention (CDC). 3 May 2020. Archived from the original on 4 May 2020.
  92. Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced
  93. Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced
  94. Symptom-Based Strategy to Discontinue Isolation for Persons with COVID-19 (2020) referenced Xiao AT, Tong YX, Zhang S (April 2020). "Profile of RT-PCR for SARS-CoV-2: a preliminary study from 56 COVID-19 patients". Clinical Infectious Diseases. doi:10.1093/cid/ciaa460. PMC   7188124 . PMID   32306036.
  95. Roser M, Ritchie H, Ortiz-Ospina E (4 March 2020). "Coronavirus Disease (COVID-19) – Statistics and Research". Our World in Data via ourworldindata.org.
  96. "UK defends coronavirus response after Reuters investigation". Reuters. 9 April 2020. Retrieved 12 April 2020. After developing a test for the new virus by Jan. 10
  97. "COVID-19 virus testing in NHS laboratories" (PDF). NHS England and NHS Improvement. 16 March 2020.
  98. "PHE novel coronavirus diagnostic test rolled out across UK". GOV.UK. Retrieved 30 March 2020; "'Increased likelihood' of China virus reaching UK". BBC News. 23 January 2020. Retrieved 30 March 2020; "PHE tells patients with suspected coronavirus to call GP or NHS 111". The Pharmaceutical Journal. 27 January 2020. Retrieved 30 March 2020.
  99. Schnirring, Lisa (11 January 2020). "China releases genetic data on new coronavirus, now deadly". CIDRAP. Archived from the original on 11 January 2020. Retrieved 12 January 2020.
  100. Schnirring, Lisa (13 January 2020). "Thailand finds Wuhan novel coronavirus in traveler from China". CIDRAP. Archived from the original on 13 January 2020. Retrieved 14 January 2020.
  101. Shu Y, McCauley J (March 2017). "GISAID: Global initiative on sharing all influenza data – from vision to reality". Euro Surveillance. 22 (13). doi:10.2807/1560-7917.ES.2017.22.13.30494. PMC   5388101 . PMID   28382917.
  102. "Laboratory Readiness for Detecting the 2019 novel coronavirus (2019-nCoV) infection in Malaysia". Director-General of Health, Malaysia. 9 February 2020.
  103. "Malaysia must ramp up testing". The Star Malaysia. 26 March 2020.
  104. "BGI Sequencer, Coronavirus Molecular Assays Granted Emergency Use Approval in China". GenomeWeb. Retrieved 9 March 2020.
  105. Sheridan C (April 2020). "Coronavirus and the race to distribute reliable diagnostics". Nature Biotechnology. 38 (4): 382–84. doi: 10.1038/d41587-020-00002-2 . PMID   32265548.
  106. 1 2 3 "日本が韓国の新型コロナウイルス対策から学べること──(1)検査体制". Newsweek Japan (in Japanese). 2 April 2020. Retrieved 5 June 2020.
  107. Совещание по вопросам развития ситуации с коронавирусной инфекцией и мерам по её профилактике
  108. {{Cite web |date= |title=CDC Diagnostic Test for COVID-19 |url=https://www.cdc.gov/coronavirus/2019-ncov/lab/testing.html |access-date=15 June 2019 |website=U.S. [[Centers for Disease Control and Prevention] (CDC)}}
  109. "Biden falsely says Trump administration rejected WHO coronavirus test kits (that were never offered)". PolitiFact.
  110. Jeong S (28 February 2020). "Korea approves 2 more COVID-19 detection kits for urgent use". Korea Biomedical Review. Retrieved 12 March 2020.
  111. "Wuhan Test Lab Opens; CDC Ships Diagnostic Kits: Virus Update". Bloomberg. 5 February 2020. Retrieved 7 February 2020.
  112. 1 2 "China virus crisis deepens as whistleblower doctor dies". AFP.com. 27 February 2012. Retrieved 7 February 2020.
  113. 日检测量达万份的"火眼"实验室连夜试运行.
  114. "BGI's Coronavirus Response? Build a Lab in Wuhan". GEN – Genetic Engineering and Biotechnology News. 12 February 2020. Retrieved 27 March 2020.
  115. "В России зарегистрирована отечественная тест-система для определения коронавируса". Interfax-Russia.ru. 14 February 2020.
  116. {{cite press release | author=CDC | title=Transcript for the CDC Telebriefing Update on COVID-19 | website=U.S. [[Centers for Disease Control and Prevention] (CDC) | date=28 February 2020 | url=https://www.cdc.gov/media/releases/2020/t0228-COVID-19-update.html | access-date=6 November 2020}}
  117. Ioannidis, John P.A. (17 March 2020). "A fiasco in the making? As the coronavirus pandemic takes hold, we are making decisions without reliable data". STAT. Retrieved 22 March 2020.
  118. Henriques, Martha. "Coronavirus: Why death and mortality rates differ". bbc.com. Retrieved 8 April 2020.
  119. "Coronavirus disease 2019 (COVID-19) pandemic: increased transmission in the EU/EEA and the UK" (PDF). European Centre for Disease Prevention and Control. 25 March 2020. pp. 15–16. Retrieved 29 March 2020. the current shortages of laboratory consumables and reagents affect diagnostic capacity and hamper the epidemic response at the national and local levels. The laboratories have experienced delayed or missing deliveries of swabbing material, plastic consumables, RNA extraction and RT-PCR reagents, and PPE. This is affecting laboratories in all EU/EEA countries.
  120. Baird RP (24 March 2020). "Why Widespread Coronavirus Testing Isn't Coming Anytime Soon". The New Yorker . Archived from the original on 28 March 2020. Retrieved 29 March 2020. South Dakota, said that her state's public-health laboratory—the only lab doing COVID-19 testing in the state—had so much trouble securing reagents that it was forced to temporarily stop testing altogether. also noted critical shortages of extraction kits, reagents, and test kits
  121. Ossola A (25 March 2020). "Here are the coronavirus testing materials that are in short supply in the US". Quartz. Archived from the original on 26 March 2020. Retrieved 29 March 2020. extract the virus's genetic material—in this case, RNA—using a set of chemicals that usually come in pre-assembled kits. 'The big shortage is extraction kits' There are no easy replacements here: 'These reagents that are used in extraction are fairly complex chemicals. They have to be very pure, and they have to be in pure solution'
  122. "COVID-19 Local Laboratory Solution". BGI – Global. Retrieved 27 March 2020.
  123. 1 2 Chen, Lulu Yilun (16 March 2020). "Heartbreak in the Streets of Wuhan". Bloomberg BusinessWeek. Retrieved 23 May 2020.
  124. 1 2 Wang W, Xu Y, Gao R, Lu R, Han K, Wu G, Tan W (March 2020). "Detection of SARS-CoV-2 in Different Types of Clinical Specimens". JAMA. 323 (18): 1843–44. doi:10.1001/jama.2020.3786. PMC   7066521 . PMID   32159775.
  125. "Comparing RT-PCR and Chest CT for Diagnosing COVID-19". HCPLive. Retrieved 23 May 2020.
  126. "LabCorp Launches Test for Coronavirus Disease 2019 (COVID-19) | Laboratory Corporation of America Holdings". ir.labcorp.com. Retrieved 16 June 2020.
  127. "Covid19 : COVID-19". questdiagnostics.com.
  128. Stein R (3 April 2020). "Coronavirus Testing Backlogs Continue As Laboratories Struggle To Keep Up With Demand". NPR.org. Retrieved 15 June 2020.
  129. Mandavilli A, Edmondson C (25 May 2020). "'This Is Not the Hunger Games': National Testing Strategy Draws Concerns". The New York Times .
  130. "Hologic's Molecular Test for the Novel Coronavirus, SARS-CoV-2, Receives FDA Emergency Use Authorization". Hologic. 16 March 2020. Retrieved 13 April 2020.
  131. 1 2 "Emergency Use Authorization". FDA. 30 April 2020. Archived from the original on 29 April 2020.
  132. "FDA Approves Abbott Laboratories Coronavirus Test, Company To Ship 150,000 Kits". IBTimes.com. 19 March 2020. Archived from the original on 20 March 2020.
  133. "Sunnyvale company wins FDA approval for first rapid coronavirus test with 45-minute detection time". EastBayTimes.com. 21 March 2020. Archived from the original on 22 March 2020.
  134. "Xpert Xpress SARS-CoV-2 has received FDA Emergency Use Authorization". cepheid.com. Retrieved 13 April 2020.
  135. Plumbo G. "Mayo Clinic develops test to detect COVID-19 infection". Mayo Clinic . Retrieved 13 March 2020.
  136. "'Test, Test, Test': WHO Chief's Coronavirus Message to World". The New York Times . Reuters. 16 March 2020. Archived from the original on 20 March 2020. Retrieved 16 March 2020.
  137. Farge E, Revill J (17 March 2020). "'Test, test, test': WHO chief's coronavirus message to world". Reuters. Retrieved 6 November 2020.
  138. "Daily COVID-19 tests per thousand people". Our World in Data. Retrieved 15 April 2020.
  139. "Total tests for COVID-19 per 1,000 people". Our World in Data. Retrieved 15 April 2020.
  140. "Covid-19 – Tests auf das Coronavirus: Wann, wo und wie?". Deutschlandfunk (in German). 19 March 2020. Retrieved 24 March 2020.
  141. Oltermann P (22 March 2020). "Germany's low coronavirus mortality rate intrigues experts". The Guardian. ISSN   0261-3077 . Retrieved 24 March 2020.
  142. Charisius H (26 March 2020). "Covid-19: Wie gut testet Deutschland?" (in German). Retrieved 26 March 2020.
  143. Weber N, Rydlink K, Irene Berres (5 March 2020). "Coronavirus und Covid-19: So testet Deutschland". Der Spiegel (in German). Retrieved 23 March 2020.
  144. "Coronavirus Disease 2019 Daily Situation Report of the Robert Koch Institute" (PDF). Robert Koch Institute. 26 March 2020. Retrieved 28 April 2020.
  145. "80% of Rapid COVID-19 Tests the Czech Republic Bought From China are Wrong". Prague Morning. 26 March 2020.
  146. Blažek V (23 March 2020). "Úřad dopředu psal, kdy mohou rychlotesty selhat. I tak je stát nasadil". Zeznam Zprávy (in Czech). Retrieved 7 April 2020. Indeed, the rapid tests that arrived from China a few days ago do not really reliably detect the infection at an early stage.
  147. DUDIK, ANDREA; TOMEK, RADOSLAV (1 April 2020). "Europe turned to China for coronavirus testing help. Why some are now regretting it". Fortune. Retrieved 28 June 2020.
  148. "Faulty virus tests cloud China's European outreach over COVID-19". The Jakarta Post. Retrieved 23 May 2020.
  149. "Coronavirus test kits purchased from China are unreliable, says Science Committee member". www.duvarenglish.com. 27 March 2020. Retrieved 28 June 2020.
  150. Soylu, Ragip (27 March 2020). "Coronavirus: Turkey rejects Chinese testing kits over inaccurate results". Middle East Eye. Retrieved 28 June 2020.
  151. "Chinese firm to replace exported coronavirus test kits deemed defective by Spain". 27 March 2020 via www.reuters.com.
  152. Sullivan H, Rawlinson K, Gayle D, Topping A, Mohdin A, Willsher K, Wintour P, Wearden G, Greenfield P (31 March 2020). "Global confirmed virus death toll passes 40,000 – as it happened". The Guardian. ISSN   0261-3077 . Retrieved 1 April 2020.
  153. "VIDEO: UAE sets up COVID-19 detection lab in just 14 days". Gulf Today. 31 March 2020.
  154. 1 2 3 "Coronavirus Pandemic Data Explorer". Our World in Data. Retrieved 28 June 2020.
  155. Romano, Andrew. (7 April 2020). "Fauci once dismissed concerns about 'silent carriers' of coronavirus. Not anymore." Yahoo News Retrieved 17 April 2020.
  156. Jeanne Whalen and Elizabeth Dwoskin (2 July 2020). "California rejected Chinese company's push to help with coronavirus testing. Was that the right move? Advisers told the state to steer clear of BGI, underscoring U.S.-China tech tension". The Washington Post .
  157. "WHO lists two COVID-19 tests for emergency use". World Health Organization (WHO). Retrieved 10 April 2020.
  158. "Health Canada approves new rapid COVID-testing kits". The Globe and Mail Inc. 13 April 2020.
  159. "The power of DNA testing for everyone". Spartan Bioscience. Archived from the original on 22 April 2020. Retrieved 14 April 2020.
  160. "Coronavirus (COVID-19): Scaling up our testing programmes" (PDF). Department of Health and Social Care. 4 April 2020.
  161. "NHS pilots home testing for coronavirus". MobiHealthNews. 24 February 2020. Archived from the original on 25 February 2020.
  162. Kenber B (6 April 2020). Smyth C, Kennedy D (eds.). "Britain has millions of coronavirus antibody tests, but they don't work" via www.thetimes.co.uk. None of the antibody tests ordered by the government is good enough to use, the new testing chief has admitted. Professor John Newton said that tests ordered from China.
  163. "Government's testing chief admits none of 3.5m coronavirus antibody kits work sufficiently". The Independent. 6 April 2020.
  164. "ICMR asks states not to use rapid test kits for two days". The Telegraph. 21 April 2020.
  165. Vogel G (21 April 2020). "Antibody surveys suggesting vast undercount of coronavirus infections may be unreliable". Science | AAAS. Retrieved 31 May 2020.
  166. "WHO Director-General's opening remarks at the media briefing on COVID-19". World Health Organization (WHO). 20 April 2020. Retrieved 31 May 2020.
  167. "MLB antibody study: 0.7% of those tested had been exposed to coronavirus". SFChronicle.com. 11 May 2020. Archived from the original on 19 May 2020. Retrieved 13 May 2020.
  168. Wagner J (15 April 2020). "M.L.B. Employees Become the Subjects of a Huge Coronavirus Study". The New York Times . Retrieved 20 May 2020.
  169. "Fewer than 1% of MLB employees test positive for COVID-19 antibodies". Los Angeles Times. 10 May 2020. Retrieved 20 May 2020.
  170. 1 2 "US Historical Data". The COVID Tracking Project.
  171. "COVID-19: Tests per day". Our World in Data. Retrieved 15 April 2020.
  172. "The MosaiQ COVID-19 Antibody Microarray". Quotient. Retrieved 1 October 2020.
  173. "Quotient Limited Announces CE Mark For Its Sars-Cov-2 (Covid-19) Antibody Microarray". Reuters. Retrieved 1 October 2020.
  174. "Coronavirus: New 'fast and accurate' antibody test developed". BBC News. Retrieved 1 October 2020.
  175. "Quotient Limited Gets CE Mark for Coronavirus Antibody Microarray". 360Dx. Retrieved 1 October 2020.
  176. "Roche's COVID-19 antibody test receives FDA Emergency Use Authorization and is available in markets accepting the CE mark". Roche (Press release). 3 May 2020. Retrieved 8 May 2020.
  177. "Roche Diagnostics GmbH Elecsys Anti-SARS-CoV-2" (PDF). U.S. Food and Drug Administration (FDA). Retrieved 8 May 2020.
  178. 1 2 3 "FDA issues emergency approval of new antigen test that is cheaper, faster and simpler". The Washington Post . 9 May 2020.
  179. Commissioner, Office of the (14 May 2020). "Coronavirus (COVID-19) Update: FDA Informs Public About Possible Accuracy Concerns with Abbott ID NOW Point-of-Care Test". FDA. Retrieved 15 May 2020.
  180. Ho D (21 May 2020). "Israel's Ben-Gurion University develops one-minute coronavirus test". BioWorld.com. Retrieved 7 June 2020.
  181. Mannix L (13 May 2020). "'Flipping a coin': COVID-19 antibody tests 'should not be used'". The Sydney Morning Herald. Retrieved 23 May 2020.
  182. Mannix L (12 May 2020). "The government bought 1.5 million antibody tests. They can't be used". The Sydney Morning Herald. Retrieved 29 May 2020.
  183. Australian Government Department of Health Therapeutic Goods Administration (22 May 2020). "Post-market evaluation of serology-based point of care tests". Therapeutic Goods Administration (TGA). Retrieved 23 May 2020.