|Severe acute respiratory syndrome|
|SARS coronavirus (SARS-CoV) is causative of the syndrome.|
Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the SARS coronavirus (SARS-CoV). Between November 2002 and July 2003, an outbreak of SARS in southern China caused an eventual 8,098 cases, resulting in 774 deaths reported in 37 countries,with the majority of cases in China (9.6% fatality rate) according to the World Health Organization (WHO). No cases of SARS have been reported worldwide since 2004. In late 2017, Chinese scientists traced the virus through the intermediary of civet cats to cave-dwelling horseshoe bats in Yunnan province.
Respiratory disease is a medical term that encompasses pathological conditions affecting the organs and tissues that make gas exchange difficult in higher organisms, and includes conditions of the upper respiratory tract, trachea, bronchi, bronchioles, alveoli, pleura and pleural cavity, and the nerves and muscles of breathing. Respiratory diseases range from mild and self-limiting, such as the common cold, to life-threatening entities like bacterial pneumonia, pulmonary embolism, acute asthma and lung cancer.
The World Health Organization (WHO) is a specialized agency of the United Nations that is concerned with international public health. It was established on 7 April 1948, and is headquartered in Geneva, Switzerland. The WHO is a member of the United Nations Development Group. Its predecessor, the Health Organisation, was an agency of the League of Nations.
Initial symptoms are flu-like and may include fever, muscle pain, lethargy symptoms, cough, sore throat, and other nonspecific symptoms. The only symptom common to all patients appears to be a fever above 38 °C (100 °F). SARS may eventually lead to shortness of breath and/or pneumonia; either direct viral pneumonia or secondary bacterial pneumonia.[ citation needed ]
Influenza-like illness (ILI), also known as acute respiratory infection (ARI) and flu-like syndrome/symptoms, is a medical diagnosis of possible influenza or other illness causing a set of common symptoms.
Myalgia, or muscle pain, is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections. Longer-term myalgias may be indicative of a metabolic myopathy, some nutritional deficiencies or chronic fatigue syndrome.
Lethargy is a state of tiredness, weariness, fatigue, or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to inadequate sleep, overexertion, overworking, stress, lack of exercise, improper nutrition, boredom, or a symptom of an illness or a disorder. It may also be a side-effect of medication or caused by an interaction between medications or medication(s) and alcohol. When part of a normal response, lethargy often resolves with rest, adequate sleep, decreased stress, physical exercise and good nutrition. Lethargy's symptoms can last days or even months.
The average incubation period for SARS is 4–6 days, although rarely it could be as short as 1 day or as long as 14 days.
Incubation period is the time elapsed between exposure to a pathogenic organism, a chemical, or radiation, and when symptoms and signs are first apparent. In a typical infectious disease, incubation period signifies the period taken by the multiplying organism to reach a threshold necessary to produce symptoms in the host.
The primary route of transmission for SARS is contact of the mucous membranes with respiratory droplets or fomites. Whilst diarrhea is common in people with SARS, the fecal-oral route does not appear to be a common mode of transmission.The basic reproduction number of SARS, R0, ranges from 2 to 4 depending on different analyses. Control measures introduced in April 2003 reduced this down to 0.4.
In medicine, public health, and biology, transmission is the passing of a pathogen causing communicable disease from an infected host individual or group to a particular individual or group, regardless of whether the other individual was previously infected.
A fomes or fomite is any nonliving object or substance capable of carrying infectious organisms, such as viruses or bacteria, and hence transferring them from one individual to another. Skin cells, hair, clothing, and bedding are common hospital sources of contamination.
Diarrhea is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin with loss of the normal stretchiness of the skin and irritable behaviour. This can progress to decreased urination, loss of skin color, a fast heart rate, and a decrease in responsiveness as it becomes more severe. Loose but non-watery stools in babies who are exclusively breastfed, however, are normal.
SARS may be suspected in a patient who has:
For a case to be considered probable, a chest X-ray must be positive for atypical pneumonia or respiratory distress syndrome.
Atypical pneumonia, also known as walking pneumonia, is the type of pneumonia not caused by one of the pathogens most commonly associated with the disease. Its clinical presentation contrasts to that of "typical" pneumonia. A variety of microorganisms can cause it. When it develops independently from another disease it is called primary atypical pneumonia (PAP).
The World Health Organization (WHO) has added the category of "laboratory confirmed SARS" for patients who would otherwise be considered "probable" but who have not yet had a positive chest X-ray changes, but have tested positive for SARS based on one of the approved tests (ELISA, immunofluorescence or PCR).
When it comes to the chest X-ray the appearance of SARS is not always uniform but generally appears as an abnormality with patchy infiltrates.
There is no vaccine for SARS. Isolation and quarantine remain the most effective means to prevent the spread of SARS. Other preventative measures include:
Many public health interventions were made to try to control the spread of the disease, which is mainly spread through respiratory droplets in the air. These interventions included earlier detection of the disease; isolation of people who are infected; droplet and contact precautions; and the use of personal protective equipment (PPE), including masks and isolation gowns.A screening process was also put in place at airports to monitor air travel to and from affected countries. Although no cases have been identified since 2004, the CDC is still working to make federal and local rapid response guidelines and recommendations in the event of a reappearance of the virus.
SARS is most infectious in severely ill patients, which usually occurs during the second week of illness. This delayed infectious period meant that quarantine was highly effective; people who were isolated before day five of their illness rarely transmitted the disease to others.
Antibiotics are ineffective, as SARS is a viral disease. Treatment of SARS is mainly supportive with antipyretics, supplemental oxygen and mechanical ventilation as needed. Antiviral medications are used as well as high doses of steroids to reduce swelling in the lungs.
People with SARS must be isolated, preferably in negative pressure rooms, with complete barrier nursing precautions taken for any necessary contact with these patients, to limit the chances of medical personnel getting infected with SARS.
Some of the more serious damage caused by SARS may be due to the body's own immune system reacting in what is known as cytokine storm.
As of 2017, there is no cure or protective vaccine for SARS that has been shown to be both safe and effective in humans.The identification and development of novel vaccines and medicines to treat SARS is a priority for governments and public health agencies around the world. MassBiologics, a non-profit organization engaged in the discovery, development and manufacturing of biologic therapies, is cooperating with researchers at NIH and the CDC in developing a monoclonal antibody therapy that demonstrated efficacy in animal models.
Several consequent reports from China on some recovered SARS patients showed severe long-time sequelae. The most typical diseases include, among other things, pulmonary fibrosis, osteoporosis, and femoral necrosis, which have led to the complete loss of working ability or even self-care ability of these cases. As a result of quarantine procedures, some of the post-SARS patients have been documented suffering from posttraumatic stress disorder (PTSD) and major depressive disorder.
SARS was a relatively rare disease; at the end of the epidemic in June 2003, the incidence was 8422 cases with a case-fatality rate of 11%.
The case-fatality ratio ranges from 0% to 50% depending on the age group of the patient.Patients under 24 were least likely to die; those 65 and older were most likely to die.
|Probable cases of SARS by country and region, 1 November 2002 – 31 July 2003.|
|Country or Region||Cases||Deaths||SARS cases dead due to other causes||Fatality (%)|
|China, People's Republic of *||5,328||349||19||6.6|
|Republic of Ireland||1||0||0||0|
|(*) Figures for the People's Republic of China exclude Hong Kong and Macau, which are reported separately by the WHO.|
|(**) Since 11 July 2003, 325 Taiwanese cases have been 'discarded'. Laboratory information was insufficient or incomplete for 135 discarded cases; 101 of these patients died.|
|Source:World Health Organization.|
The viral outbreak can be genetically traced to a colony of cave-dwelling horseshoe bats in China's Yunnan province.
The SARS epidemic appears to have started in Guangdong Province, China in November 2002 where the first case was reported that same month. The patient, a farmer from Shunde, Foshan, Guangdong, was treated in the First People's Hospital of Foshan. The patient died soon after, and no definite diagnosis was made on his cause of death. Despite taking some action to control it, Chinese government officials did not inform the World Health Organization of the outbreak until February 2003. This lack of openness caused delays in efforts to control the epidemic, resulting in criticism of the People's Republic of China from the international community. China has since officially apologized for early slowness in dealing with the SARS epidemic.
The outbreak first appeared on 27 November 2002, when Canada's Global Public Health Intelligence Network (GPHIN), an electronic warning system that is part of the World Health Organization's Global Outbreak Alert and Response Network (GOARN), picked up reports of a "flu outbreak" in China through Internet media monitoring and analysis and sent them to the WHO. While GPHIN's capability had recently been upgraded to enable Arabic, Chinese, English, French, Russian, and Spanish translation, the system was limited to English or French in presenting this information. Thus, while the first reports of an unusual outbreak were in Chinese, an English report was not generated until 21 January 2003.The first super-spreader, Zhou Zoufeng was admitted to the Sun Yat-sen Memorial Hospital in Guangzhou on January 31, which soon spread the disease to nearby hospitals.
Subsequent to this, the WHO requested information from Chinese authorities on 5 and 11 December. Despite the successes of the network in previous outbreak of diseases, it didn't receive intelligence until the media reports from China several months after the outbreak of SARS. Along with the second alert, WHO released the name, definition, as well as an activation of a coordinated global outbreak response network that brought sensitive attention and containment procedures.By the time the WHO took action, over 500 deaths and an additional 2,000 cases had already occurred worldwide.
In early April, after Jiang Yanyong pushed to report the danger to China,there appeared to be a change in official policy when SARS began to receive a much greater prominence in the official media. Some have directly attributed this to the death of American James Earl Salisbury. It was around this same time that Jiang Yanyong made accusations regarding the undercounting of cases in Beijing military hospitals. After intense pressure, Chinese officials allowed international officials to investigate the situation there. This revealed problems plaguing the aging mainland Chinese healthcare system, including increasing decentralization, red tape, and inadequate communication.
Many healthcare workers in the affected nations risked and lost their lives by treating patients and trying to contain the infection before ways to prevent infection were known.
The epidemic reached the public spotlight in February 2003, when an American businessman traveling from China, Johnny Chen, became afflicted with pneumonia-like symptoms while on a flight to Singapore. The plane stopped in Hanoi, Vietnam, where the victim died in The French Hospital of Hanoi. Several of the medical staff who treated him soon developed the same disease despite basic hospital procedures. Italian doctor Carlo Urbani identified the threat and communicated it to WHO and the Vietnamese government; he later succumbed to the disease.
The severity of the symptoms and the infection among hospital staff alarmed global health authorities, who were fearful of another emergent pneumonia epidemic. On 12 March 2003, the WHO issued a global alert, followed by a health alert by the United States Centers for Disease Control and Prevention (CDC). Local transmission of SARS took place in Toronto, Ottawa, San Francisco, Ulaanbaatar, Manila, Singapore, Taiwan, Hanoi and Hong Kong whereas within China it spread to Guangdong, Jilin, Hebei, Hubei, Shaanxi, Jiangsu, Shanxi, Tianjin, and Inner Mongolia.[ citation needed ]
The disease spread in Hong Kong from Liu Jianlun, a Guangdong doctor who was treating patients at Sun Yat-Sen Memorial Hospital.He arrived in February and stayed on the ninth floor of the Metropole Hotel in Kowloon, infecting 16 of the hotel visitors. Those visitors traveled to Canada, Singapore, Taiwan (Republic of China), and Vietnam, spreading SARS to those locations.
Another larger cluster of cases in Hong Kong centred on the Amoy Gardens housing estate. Its spread is suspected to have been facilitated by defects in its drainage system. Concerned citizens in Hong Kong worried that information was not reaching people quickly enough and created a website called sosick.org, which eventually forced the Hong Kong government to provide information related to SARS in a timely manner.The first cohort of affected people were discharged from hospital on 29 March 2003.
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The first case of SARS in Toronto, Canada was identified on February 23, 2003.Beginning with an elderly woman, Kwan Sui-Chu, returning from a trip to Hong Kong, the virus killed her on March 5 and eventually infected 257 individuals in the province of Ontario. The trajectory of this outbreak is typically divided into two phases, the first centring around her son Tse Chi Kwai, who infected other patients at the Scarborough Grace Hospital and died on March 13. The second major wave of cases was clustered around accidental exposure among patients, visitors, and staff within the North York General Hospital. The WHO officially removed Toronto from its list of infected areas by the end of June, 2003.
The official response by the Ontario provincial government and Canadian federal government has been widely criticized in the years following the outbreak. Brian Schwartz, vice-chair of the Ontario's SARS Scientific Advisory Committee, described public health officials’ preparedness and emergency response at the time of the outbreak as “very, very basic and minimal at best”. [ citation needed ]Critics of the response often cite poorly outlined and enforced protocol for protecting healthcare workers and identifying infected patients as a major contributing factor to the continued spread of the virus. The atmosphere of fear and uncertainty surrounding the outbreak resulted in staffing issues in area hospitals when healthcare workers elected to resign rather than risk exposure to SARS.
The CDC and Canada's National Microbiology Laboratory identified the SARS genome in April 2003.Scientists at Erasmus University in Rotterdam, the Netherlands demonstrated that the SARS coronavirus fulfilled Koch's postulates thereby confirming it as the causative agent. In the experiments, macaques infected with the virus developed the same symptoms as human SARS victims.
In late May 2003, studies were conducted using samples of wild animals sold as food in the local market in Guangdong, China. The results found that the SARS coronavirus could be isolated from masked palm civets (Paguma sp.), even if the animals did not show clinical signs of the virus. The preliminary conclusion was the SARS virus crossed the xenographic barrier from asian palm civet to humans, and more than 10,000 masked palm civets were killed in Guangdong Province. The virus was also later found in raccoon dogs (Nyctereuteus sp.), ferret badgers (Melogale spp.), and domestic cats. In 2005, two studies identified a number of SARS-like coronaviruses in Chinese bats.
Phylogenetic analysis of these viruses indicated a high probability that SARS coronavirus originated in bats and spread to humans either directly or through animals held in Chinese markets. The bats did not show any visible signs of disease, but are the likely natural reservoirs of SARS-like coronaviruses. In late 2006, scientists from the Chinese Centre for Disease Control and Prevention of Hong Kong University and the Guangzhou Centre for Disease Control and Prevention established a genetic link between the SARS coronavirus appearing in civets and humans, bearing out claims that the disease had jumped across species.
In December 2017, "after years of searching across China, where the disease first emerged, researchers reported ... that they had found a remote cave in Yunnan province, which is home to horseshoe bats that carry a strain of a particular virus known as a coronavirus. This strain has all the genetic building blocks of the type that triggered the global outbreak of SARS in 2002." The research was "published in the journal Public Library of Science Pathogens" and "was led by Shi Zheng-Li and Cui Jie of the Wuhan Institute of Virology, China... In their paper, the Chinese team warn that another deadly outbreak of SARS could emerge at any time. As they point out, the cave where they discovered their strain is only a kilometre from the nearest village."
The World Health Organization declared severe acute respiratory syndrome contained on 9 July 2003. In the following years, four SARS cases were reported in China between December 2003 and January 2004. There were also three separate laboratory accidents that resulted in infection. In one of these cases, an ill lab worker spread the virus to several other people.Study of live SARS specimens require a BSL-3 facility; some studies of inactivated SARS specimens can be done at BSL-2 facilities.
Fear of contracting the virus from consuming infected wild animals resulted in public bans and reduced business for meat markets throughout southern China and Hong Kong. [ citation needed ]In China, Cantonese foodways, which often incorporate a wide range of meat sources, were frequently indicted as an important contributing factor to the origins of the SARS outbreak.
Toronto's Asian minority population faced increased discrimination over the course of the city's outbreak. Local advocacy groups reported Asians being passed over by real-estate agents and taxi drivers and shunned on public transportation. [ citation needed ]In Boston and New York City, rumors and April Fools pranks gone awry resulted in an atmosphere of fear and substantial economic loss in the cities’ Chinatowns.
Coronaviruses are species of virus belonging to the subfamily Coronavirinae in the family Coronaviridae, in the order Nidovirales. Coronaviruses are enveloped viruses with a positive-sense single-stranded RNA genome and with a nucleocapsid of helical symmetry. The genomic size of coronaviruses ranges from approximately 26 to 32 kilobases, the largest for an RNA virus.
The following is a timeline of the 2002–04 outbreak of severe acute respiratory syndrome (SARS).
The Severe acute respiratory syndrome-related coronavirus, sometimes shortened to SARS-CoV, is the virus that causes severe acute respiratory syndrome (SARS). On April 16, 2003, following the outbreak of SARS in Asia and secondary cases elsewhere in the world, the World Health Organization (WHO) issued a press release stating that the coronavirus identified by a number of laboratories was the official cause of SARS. Samples of the virus are being held in laboratories in New York City, San Francisco, Manila, Hong Kong, and Toronto.
The SARS conspiracy theory began to emerge during the severe acute respiratory syndrome (SARS) outbreak in China in the spring of 2003, when Sergei Kolesnikov, a Russian scientist and a member of the Russian Academy of Medical Sciences, first publicized his claim that the SARS coronavirus is a synthesis of measles and mumps. According to Kolesnikov, this combination cannot be formed in the natural world and thus the SARS virus must have been produced under laboratory conditions. Another Russian scientist, Nikolai Filatov, head of Moscow's epidemiological services, had earlier commented that the SARS virus was probably man-made. However, independent labs concluded these claims to be premature since the SARS virus is a coronavirus, whereas measles and mumps are paramyxoviruses. The primary differences between a coronavirus and a parmyxovirus are in their structures and method of infection, thus making it implausible for a coronavirus to have been created from two paramyxoviruses.
Coronaviridae is a family of enveloped, positive-sense, single-stranded RNA viruses. The viral genome is 26–32 kb in length. The particles are typically decorated with large (~20 nm), club- or petal-shaped surface projections, which in electron micrographs of spherical particles create an image reminiscent of the solar corona. Members of this family are thus referred to as coronaviruses.
Viral pneumonia is a pneumonia caused by a virus. Viruses are one of the two major causes of pneumonia, the other being bacteria; less common causes are fungi and parasites. Viruses are the most common cause of pneumonia in children, while in adults bacteria are a more common cause.
Human coronavirus NL63 or HCoV-NL63 is a species of Alphacoronavirus that was identified in late 2004 in a seven-month-old child with bronchiolitis in the Netherlands. Infection with the virus has been confirmed worldwide, and has an association with many common symptoms and diseases. Associated diseases include mild to moderate upper respiratory tract infections, severe lower respiratory tract infection, croup and bronchiolitis. The virus is found primarily in young children, the elderly, and immunocompromised patients with acute respiratory illness. It also has a seasonal association in temperate climates. A study performed in Amsterdam estimated the presence of HCoV-NL63 in approximately 4.7% of common respiratory illnesses. Further studies confirmed that the virus is not an emerging virus, but rather one that continually circulates the human population.
Canine coronavirus is a virus of the family Coronaviridae that causes a highly contagious intestinal disease worldwide in dogs. It was discovered in 1971 in Germany during an outbreak in sentry dogs.
Yuen Kwok-yung (袁國勇) is a Hong Kong microbiologist, physician and surgeon. He graduated from the University of Hong Kong with distinction in Medicine. He is a Fellow of the Royal College of Physicians, Surgeons and Pathologists. After years of clinical and laboratory training, he established the infectious disease service and rapid molecular diagnosis for cytomegalovirus and tuberculosis at the Queen Mary Hospital, the teaching hospital of the University of Hong Kong. His major research interest is on microbial hunting and novel microbes in emerging infectious diseases.
Joseph Sriyal Malik Peiris (裴偉士), ( ඡීරිස්), ( பீறிஸ்), FRS, Légion d'Honneur, was born on 10 November 1949, in Sri Lanka. He is referred to in scientific publications and media reports as JSM Peiris, JS Peiris, Joseph Peiris and, most commonly, as Malik Peiris. His close family and friends prefer to use the middle name Sriyal. He is a distinguished old boy of St. Anthony's College Kandy and later studied medicine at the University of Ceylon, Peradeniya, Sri Lanka. This was followed by post graduate study at the Sir William Dunn School of Pathology, University of Oxford, UK, leading to the award of the DPhil degree. After further work in the UK and Sri Lanka, he founded the clinical diagnostic and public health virology laboratory at Queen Mary Hospital, which is part of the University of Hong Kong, in 1995. Malik Peiris and his team of scientists and doctors were strategically placed to face the challenges of the Avian influenza virus outbreak, the Severe Acute Respiratory Syndrome (SARS) coronavirus outbreak, and the Middle Eastern Respiratory Syndrome (MERS) coronavirus outbreak. Original research carried out by the Hong Kong laboratories have made major contributions to the knowledge of the causative viruses of these diseases, and the understanding, diagnosis, treatment and prevention of the diseases that these viruses cause. During the years 2003-2004, Malik Peiris was credited with authoring the highest number of high impact publications in the scientific world. He and his co-workers have published more than 600 scientific papers in a research career spanning more than 35 years and are credited with 32 scientific patents relating to diagnosis of viral infections. He currently holds the Tam Wah-Ching Professorship, Division of Public Health Laboratory Sciences, University of Hong Kong, where he continues to lead ground breaking research with a particular interest in newly emerging virus diseases at the animal-human interface.
W. Ian Lipkin is the John Snow Professor of Epidemiology at the Mailman School of Public Health at Columbia University and Professor of Neurology and Pathology at the College of Physicians and Surgeons at Columbia University. Lipkin is also Director of the Center for Infection and Immunity, an academic laboratory for microbe hunting in acute and chronic diseases.
Middle East respiratory syndrome-related coronavirus (MERS-CoV), or EMC/2012 (HCoV-EMC/2012), is a novel positive-sense, single-stranded RNA virus of the genus Betacoronavirus.
Middle East respiratory syndrome (MERS), also known as camel flu, is a viral respiratory infection caused by the MERS-coronavirus (MERS-CoV). Symptoms may range from mild to severe. They include fever, cough, diarrhea, and shortness of breath. Disease is typically more severe in those with other health problems. Mortality is about one-third of diagnosed cases.
Bat SARS-like coronavirus WIV1, also sometimes called SARS-like coronavirus WIV1, is a newly identified CoV isolated from Chinese rufous horseshoe bats. The discovery confirms that bats are the natural reservoir of the SARS virus. Phylogenetic analysis shows the possibility of direct transmission of SARS from bats to humans without the intermediary Chinese civets, as previously believed. It is a single-stranded, enveloped, positive-sense RNA betacoronavirus.
HCoV-EMC/2012, or Human Coronavirus Erasmus Medical Center/2012 is the name of a novel strain of coronavirus isolated from the sputum of the first person to become infected with what was later named Middle East respiratory syndrome coronavirus, or MERS-CoV.
A bat-borne virus is any virus whose primary reservoir is any species of bat. The viruses species include coronaviruses, hantaviruses, lyssaviruses, lassa virus, Henipavirus, Ebola virus and Marburg virus. Bat-borne viruses are among the most important of the emerging viruses.
Since 2012, an outbreak of Middle East respiratory syndrome coronavirus has affected several countries, primarily in its namesake, the Middle East. The virus, which causes Middle East respiratory syndrome (MERS), is a newly emerged betacoronavirus that was first identified in a patient from Saudi Arabia in April 2012.
The Severe acute respiratory syndrome (SARS) Network refers to the system by which the SARS virus managed to have initial seedings in many different geographical locations, with intense but tightly circumscribed activity, without breaking out into an epidemic.
The rapid spread of Severe acute respiratory syndrome (SARS) in healthcare workers (HCW)—most notably in Toronto hospitals—during the global outbreak of SARS in 2002-2003 contributed to dozens of identified cases, some of them fatal. Researchers have found several key reasons for this development, such as the high-risk performances of medical operations on patients with SARS, inadequate use of protective equipment, psychological effects on the workers in response to the stress of dealing with the outbreak, and lack of information and training on treating SARS. Lessons learned from this outbreak among healthcare workers have contributed to newly developed treatment and prevention efforts and new recommendations from groups such as the Centers for Disease Control and Prevention (CDC).
Since 2004, there haven't been any known cases of SARS reported anywhere in the world.
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