The 2009 flu pandemic in the United States was caused by a novel strain of the Influenza A/H1N1 virus, commonly referred to as "swine flu", that was first detected on 15 April 2009. [114] While the 2009 H1N1 virus strain was commonly referred to as "swine flu", there is no evidence that it is endemic to pigs (i.e. actually a swine flu) or of transmission from pigs to people; instead, the virus spreads from person to person. [115] On April 25, the World Health Organization declared a public health emergency, followed concurringly by the Obama administration on April 26. [114]
The U.S. Centers for Disease Control and Prevention (CDC) reported that during the outbreak about half of all influenza viruses being reported were 2009 H1N1 viruses, with the other half being those of the regular seasonal influenza. Unique to this particular strain, about 60% of the 2009 H1N1 influenza cases were occurring among people between 5 years and 24 years of age, and 40% of the hospitalizations were occurring among children and young adults. About 80% of the deaths were in people younger than 65 years of age. The CDC noted that this differed greatly from typical seasonal influenza epidemics, during which about 70% to 90% of deaths are estimated to occur in people 65 years and older. Antibody studies showed that children had no existing cross-reactive antibody to the 2009 H1N1 influenza virus, while about one-third of adults older than 60 years of age had cross-reactive antibody. [116]
By April 21, 2009, CDC had begun working to develop a virus that could be used to make a vaccine to protect against the new virus. Following preparation for distribution beginning in June, the first doses were administered in October 2009. [117] On August 10, 2010, WHO declared an end to the global 2009 H1N1 influenza pandemic. However, the virus continues to circulate as a seasonal flu virus, and cause illness, hospitalization, and deaths worldwide every year. [118] From April 12, 2009, to April 10, 2010, the CDC estimates there were 60.8 million cases (range: 43.3 - 89.3 million), 274,304 hospitalizations (range: 195,086 - 402,719), and 12,469 deaths (range: 8868 - 18,306) in the United States due to the virus. [119]
A follow-up study done in September 2010 showed that the risk of serious illness resulting from the 2009 H1N1 flu was no higher than that of the yearly seasonal flu. [120] For comparison, the CDC estimates the global H1N1 death toll at 284,000 and the WHO estimates that 250,000 to 500,000 people die of seasonal flu annually. [121]
The earliest reported cases in the US began appearing in early April 2009, in California. [122] [123] In late April, the Centers for Disease Control and Prevention (CDC) activated its Emergency Operations Center and declared a public health emergency. [124] On April 25, the World Health Organization (WHO) declared a public health emergency of international concern. WHO declared H1N1 a pandemic on June 11.[ citation needed ]
By the end of May, the flu had infected people in all 50 states. As of June 16, the total number of confirmed cases was 27,717 [125] and on June 25, the CDC said there were over one million (1,000,000) cases, most of which had not been reported or diagnosed. [126] [127] Deaths relating to influenza began appearing in the US in late April, and by early June, 15 states had reported fatalities related to or directly occurring from the virus.
By October 5, the first doses of an H1N1 vaccine were given in the U.S. The CDC distributed vaccines for the flu [128] using mechanisms already in place for its Vaccines for Children (VFC) program. [129]
On October 24, and the CDC said more than 1,000 had died from the flu. President Obama declared a national emergency. [130] [114] [131] On December 10, 2009, the CDC reported an estimated 50 million Americans or 1 in 6 had been infected and 10,000 had died. [132] On December 23, 2009, the CDC reported a reduction of the disease by 59% percent. On February 12, the CDC reported 57 million Americans had been sickened, 257,000 had been hospitalized and 11,690 people had died (including 1,180 children) due to flu from April through to mid-January. [133] [134]
The Centers for Disease Control and Prevention (CDC) identified the first two A/09(H1N1) swine flu cases in California on April 17, 2009, via the Border Infectious Disease Program, [135] for a San Diego County child, and a naval research facility studying a special diagnostic test, where influenza sample from the child from Imperial County was tested. [136] By April 21, enhanced surveillance was established to search for additional cases in both California and Texas and the CDC determined that the virus strain was genetically similar to the previously known A(H1N1) swine flu circulating among pigs in the United States since about 1999.[ citation needed ]
It was established that the virus was a combination of human, North American swine, and Eurasian swine influenza viruses; the viruses from the initial two Californian cases were also noted to be resistant to amantadine and rimantadine, two common influenza antiviral drugs. [137] No contact with pigs was found for any of the seven Californian nor either of the two Texas cases, suggesting human-to-human transmission of the virus.[ citation needed ]
On April 28, 2009, the director of the Centers for Disease Control and Prevention confirmed the first official US death of swine flu. Tests confirmed that a 23-month-old toddler from Mexico, who was probably infected there, died on April 27 from the flu while visiting Texas. [138]
Cases of H1N1 spread rapidly across the United States, with particularly severe outbreaks in Texas, New York, Utah, and California. Early cases were associated with recent travel to Mexico; many were students who had traveled to Mexico for spring break. [139] On May 4, 2009, the CDC reported one death, 286 confirmed cases of H1N1 flu across 36 states, 35 hospitalizations, and expected H1N1 to eventually spread to all states. A large number of cases, according to medics, have happened in the days that preceded the launch of the alert and came out only in these days due to a massive backlog. [140] By May 5, 2009, the number had risen to 403 [125] and a second death was reported in Texas. [141] The CDC and government officials had expressed cautious optimism about the severity and spread of H1N1. [142] [143]
Changes in surveillance of cases of influenza-like illness, including new guidelines for identifying cases to test, increased laboratory testing, and new test kits able to distinguish this novel strain, resulted in a spike in the percent of cases tested positive for influenza. Of the positive cases, about a third were due to the novel strain. Also found were a substantial number of cases where the strain could not be subtyped. [144]
The proportion of US deaths due to pneumonia and influenza climbed above the epidemic threshold in the 2007–2008 winter flu season but not in the 2008–2009 season. Although the 2009 H1N1 outbreak reached epidemic levels of infection early in 2009, it did not contribute to epidemic levels of pneumonia and influenza related deaths until October 2009.[ citation needed ]
2009 US Swine Flu Summary | |
---|---|
Number of Confirmed Cases/Deaths | See Table Above |
Number of States/Territories with Reported Cases | 56 |
Number of States/Territories with Confirmed Deaths | 55 |
Earliest Confirmed Infection in US | March 28, 2009 [145] |
First Death Inside the US | April 27, 2009 [138] |
First Death of US Citizen | May 5, 2009 [146] |
Number of People Hospitalized | 9,079 (as of September 3) [147] |
Fatalities | 593 (as of September 3) [147] |
In early October 2009, the Centers for Disease Control and Prevention announced that swine flu was widespread across the country. It also said there was significant flu activity in virtually all states, which was considered to be quite unusual for this time of year. There was particular worry about pregnant women. As of late August, 100 had been hospitalized in intensive care units and 28 had died since the beginning of the outbreak in April. On October 1, it was acknowledged that a recruit in basic training in Fort Jackson, South Carolina, was the Army's first swine flu death. The recruit fell ill on September 1 and died of pneumonia on September 10.[ citation needed ]
Dell Children's Medical Center in Austin, Texas, erected two tents in its parking lot to handle emergency room visits, and hospitals around Colorado Springs recorded a 30 percent spike in flu visits. As pediatric cases were increasing, the Dept. of Health and Human Services released 300,000 courses of children's liquid Tamiflu from the national pandemic stockpile in late September, with the first batches sent to Texas and Colorado.[ citation needed ]
In late September, the disease centers reported that 936 had died of flu symptoms or of flu-associated pneumonia since August 30, when it began a new count of deaths, including some without laboratory-confirmed swine flu. [148]
The Agriculture Department reported on October 16 that three pigs at the Minnesota State Fair, in St. Paul, were tested positive in late August for H1N1 virus, which were the first cases in the country, although infected pigs had been found in eight other countries. There were 103 pigs tested at the Fair, including the three infected, though all appeared healthy. Scientists said the virus was already spreading widely among people, and, in fact, was more common in humans than in pigs, so humans were more likely to catch it from others than from pigs. [149]
In mid-October, it was reported that flu caused by the H1N1 virus was widespread in 41 states, and flu-like illnesses accounted for 6.1 percent of all doctor visits, which was considered high[ citation needed ], particularly for October. Forty-three children had died from H1N1 since August 30, which is approximately the number that usually dies in an entire flu season. Nineteen of the forty-three were teenagers while sixteen were between ages five to eleven. The rest were under five.[ citation needed ] It is reported that the severity of the disease was not increasing. About fifteen to twenty percent of the patients hospitalized for the flu were placed in the intensive care unit, a level similar to that for seasonal flu.[ citation needed ]
Projections of the supply of H1N1 vaccine had decreased significantly from a level of 120 million doses ready in October, estimated during the summer, to an estimate of 28 to 30 million doses by the end of the month. On October 14, 11.4 million doses of the H1N1 vaccine were said to be available. As of November 20, 2009, the CDC reported sharp declines in H1N1 activity throughout the United States, with influenza-like illness (which may also include meningitis, pneumonia, strep pharyngitis, gastroenteritis, and the common cold) accounting for 5.5% of doctors visits, down sharply from 8% in late October, the peak of the second wave. However, taking the vaccine is still urged by the CDC, as a third wave of the disease may sweep across the US, possibly in January/February 2010. [150] [ needs update ] As of December 24, the second wave of H1N1 has clearly peaked, with pneumonia and influenza deaths falling below the epidemic threshold for the first time in 11 weeks, and the proportion of doctors visits due to influenza-like illness falling to baseline (2.3%), down from 5.5% 1 month before, on November 20. However, it was reported that influenza activity was beginning to increase in West Virginia, with 5.2% of patients treated by West Virginia health care providers having influenza-like illness, a major increase from 2% of patients treated by West Virginia health care providers having influenza-like illness in November.[ citation needed ]
On August 10, 2010, WHO declared an end to the global 2009 H1N1 influenza pandemic. However, the virus continues to circulate as a seasonal flu virus, and cause illness, hospitalization, and deaths worldwide every year. [151]
The new strain was identified as a combination of several different strains of Influenzavirus A, subtype H1N1, including separate strains of this subtype circulating in humans (see human influenza) and in pigs (see swine influenza). The strain transmits between humans and was initially reported to have a relatively high mortality rate in Mexico. In April 2009 the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) expressed serious concerns that the new strain had the potential to become an influenza pandemic. [152] On April 25 it was reported that, because the virus was already widespread, containment would be "nearly impossible." [153]
By this time, there had also been speculation that the flu death toll in Mexico could be lower than first thought. Gerald Evans, head of the Association of Medical Microbiology and Infectious Disease Canada and a member of a federal pandemic-planning committee, said on April 29: [154]
There was a lot of speculation and what seemed to be evidence there were dozens and dozens of deaths. Careful analysis showed these people likely died of something else, and not influenza. That's really good news, and that would fit with what we've seen outside of Mexico.
Another Canadian expert, Neil Rau, criticized the WHO's decision to raise its pandemic alert to level 5, saying: [155]
I don't agree with (the WHO) because I think it's a panic metre, not a pandemic metre. [...] If that flu-like illness is not deadly, I don't know what the cause for alarm is for people who are not really sickened by this virus. [...] I'm really eager to know how much worse this is than seasonal flu. So far it's looking like it's not that serious.
CNN noted on April 28, 2009, that in any individual week between January 1 and April 18, there had been at least 800 deaths in the U.S. due to normal influenza, which is higher than the 150 total deaths worldwide from the swine flu up to that time. [156]
As of May 28, 2010, the official U.S. death toll attributed directly to the novel H1N1 and seasonal influenza was 2,117. [157] This total exceeds the 849 U.S. deaths directly attributed to seasonal influenza in 2006. [158] Many of the other deaths commonly attributed to influenza are caused by complicated influenza, where a second infection causes death, usually pneumonia (of which 48,657 of 55,477 official deaths in 2006 occurred in people aged 65 years and older). [158] [159] The final estimate was of over 12,000 deaths over the course of the pandemic (April 2009 – April 2010). [119]
The CDC reported that during the outbreak about half of all influenza viruses being detected through laboratory reports were 2009 H1N1 viruses, with the other half being those of the regular seasonal influenza viruses. Surveillance reports indicated that about 57% of the 2009 H1N1 influenza confirmed and probable cases were occurring among people between 5 years and 24 years of age, and 41% of the hospitalizations were occurring among older children and young adults. The highest rates of hospitalization were among children younger than 5 years of age; the next highest hospitalization rate was in people 5 years to 24 years of age. Antibody studies showed that children had no existing cross-reactive antibody to the 2009 H1N1 influenza virus, while about one-third of adults older than 60 years of age had cross-reactive antibody. One possible explanation for this pre-existing antibody in older adults was that they may have had previous exposure, either through infection or vaccination, to an influenza A H1N1 virus that was more closely related to the 2009 H1N1 flu virus. [160]
Based on data from previous influenza pandemics and seasonal influenza, pregnant women had been recognized as a high-risk group early in the outbreak. People with other previously recognized medical conditions that placed them at high risk of complications from seasonal influenza also appeared to be at increased risk of complications from 2009 H1N1 influenza. One report found that seventy-one percent of hospitalized patients had one or more underlying chronic medical conditions and reported deaths had occurred in people ranging in age from 22 months old to 57 years old. Also, only 13% of hospitalizations had occurred in people 50 years and older, and there were few cases and no deaths in people older than 65 years, which was unusual when compared with seasonal flu. [161]
The Federal response remained at US Pandemic Stage 0, congruent with the World Health Organization (WHO) Pandemic Phases 1, 2 and 3; [162] [163] however, the WHO's Pandemic Phase was raised to 4 on April 27, which is congruent with US Pandemic Stage 2. [164] On April 29, the WHO raised the pandemic alert level to phase 5. [165]
The United States federal government declared a public health emergency, and several U.S. states then indicated that they may follow suit. Secretary of Homeland Security Janet Napolitano noted that this declaration was standard operating procedure, which was also done for the 2009 presidential inauguration and for flooding. [166]
After many days of deliberation the WHO declared that the current influenza had become a true pandemic, raising the Pandemic Alert level to Phase 6, the highest on the WHO scale and congruent with U.S. Federal Government Response Stages 3–6. [167]
An official for the White House said on April 24 that "the White House is taking the situation seriously and monitoring for any new developments. The president has been fully briefed." [168] President Barack Obama stated that "We are closely monitoring the emerging cases of swine flu." He also noted, "This is obviously a cause for concern ... but it is not a cause for alarm." [169] Obama suggested that U.S. schools should consider shutting down, as a future possibility, if their students were to become infected. [170] White House Press Secretary Robert Gibbs said the effort to get a team in place to respond to the health scare had not been hindered by the lack of a secretary of Health and Human Services or appointees in any of the department's 19 key posts. [171] The president's nominee, Kansas Gov. Kathleen Sebelius, was still awaiting confirmation from the U.S. Senate until passing on April 28. The President had not yet made appointments to either the Commissioner of the Food and Drug Administration, the Surgeon General, or the Director of the Centers for Disease Control and Prevention. [171] The current acting Surgeon General, Steven K. Galson, was also currently serving as the Acting Assistant Secretary for Health. [172]
On April 30, it was reported that an aide to Steven Chu, the US Energy Secretary, had fallen ill from the virus after helping arrange President Obama's trip to Mexico. [173] However, the White House stated that the President was not at risk of contracting the flu. [173] Kathleen Sebelius was confirmed as the Secretary of Health and Human Services by the Senate on April 28, 2009, with a vote of 65–31. [174] [175]
On October 24, President Obama declared the 2009 H1N1 swine flu a national emergency. [176] The declaration made it easier for U.S. medical facilities to handle a surge in flu patients by allowing the waiver of some requirements of Medicare, Medicaid and other federal health insurance programs as needed.
During the week of April 19, 2009, the CDC activated its Emergency Operations Center (EOC), with RADM Stephen Redd as the Incident Commander, to augment the ongoing investigation of human cases of swine influenza A (H1N1). [177] More than 250 CDC professionals worked from the CDC EOC as part of the agency's response. [178] As of May 4, 2009, the CDC reported that it had deployed 25% of the supplies and medicines in the Strategic National Stockpile to the various states. [179]
As of April 29, only the CDC could confirm U.S. swine flu cases. [180] Besser stated during an April 30 press briefing that California and New York had diagnostic test kits, and that the kits would be sent to all states starting the following day. [181] On May 6, the CDC announced that testing kits were now available for all states. It was expected this would generate an increase in the number of confirmed cases as more states began doing their own tests. [182]
In the United States, the majority of the 70 National Respiratory and Enteric Virus Surveillance System (NREVSS) laboratories do not report the influenza A subtype.[ citation needed ]
However, in 2007, human infection with a novel influenzavirus A became a nationally notifiable condition. Novel influenza A virus infections include all human infections with influenza A viruses that are different from currently circulating human influenza H1 and H3 viruses. These viruses include those that are subtyped as nonhuman in origin and those that are unsubtypable with standard methods and reagents. [183] The new strain responsible for this outbreak was one such virus.[ citation needed ]
Initially the CDC had issued a recommendation that schools close for as long as two weeks if a student catches swine flu. [184] Some school districts closed all schools if a single child was classified as probable. [139] On May 5 the CDC retracted its advice stating that schools that were closed based on previous CDC guidance related to this outbreak may reopen. [185] By that time at least 726 schools nationwide serving more than 480,000 students had closed for at least some period of time. [184] The CDC amended its advice, citing new information on disease severity and the limiting effectiveness of school closure as a control measure. [185] The new advice given stated, "Decisions about school closure should be at the discretion of local authorities based on local considerations, including public concern and the impact of school absenteeism and staffing shortages." [185]
The Food and Drug Administration (FDA) authorized emergency use of medicines and diagnostic tests for flu. (FDA is part of Department of Health and Human Services.) [186] The FDA stated it was also responding to this threat by:
On May 6, 2009, the FDA announced that it had approved a new manufacturing facility for seasonal flu vaccine, owned by Sanofi Pasteur, which could also be used for manufacturing a vaccine for the new H1N1 flu strain. [188] The FDA also issued a warning for consumers to be wary of products claiming to cure or prevent swine flu. [189]
Secretary Napolitano stated that DHS was the principal federal office for incidents such as the H1N1 flu outbreak, and "Under that role, we have been leading a true collaborative effort." [190] The Department of Homeland Security issued a document, dated November 1, 2005, entitled "National Strategy for Pandemic Influenza", detailing planning for potential pandemics. https://web.archive.org/web/20090507013213/http://www.pandemicflu.gov/plan/federal/pandemic-influenza.pdf
The State Department suggested travelers to Mexico stay alert and comply with guidance from Mexican public health officials, but did not impose any travel restrictions on US citizens to Mexico. [191] However, the State Department did recommend US citizens avoid non-essential travel to Mexico. [192]
The Department of Agriculture (USDA) reported no swine in the US have been infected so far, but the USDA is monitoring swine across the US for signs of infection. [193]
The Department of Commerce sent a letter to Russia and China requesting that those countries lift their ban on American pork products. [194]
The Department of Defense (DOD) monitored the swine flu situation and had contingency plans to deal with such outbreaks. [195] As of May 7, 2009, the DOD reported 104 confirmed cases among Armed Forces personnel and their families. DOD maintained a daily summary and map. [196]
The Department of Education provided guidance to schools in the US affected by swine flu, as well as precautions to take. [197]
Schools closed in many states in response to local flu outbreaks. By April 30, 2009, 300 U.S. schools and school districts had announced closures in response to the outbreak, giving 169,000 students time off. [198] On May 4, 2009, about 533 schools in 24 states in the U.S. were closed, affecting about 330,000 students. [199] On September 25, 2009, 42 schools were closed in eight states as the second wave of the pandemic began. [200]
On May 5, Kathleen Sebelius stated in a CDC news conference that school closures for single confirmed cases of H1N1 influenza were unnecessary, but that children displaying an influenza-like illness should stay home. [201]
Several US airlines waived fees for cancellations and flight changes. [202] At least one cruise line changed itinerary to avoid Mexican ports of call. [203]
[ citation needed ]
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Influenza A virus (IAV) is the only species of the genus Alphainfluenzavirus of the virus family Orthomyxoviridae. It is a pathogen with strains that infect birds and some mammals, as well as causing seasonal flu in humans. Mammals in which different strains of IAV circulate with sustained transmission are bats, pigs, horses and dogs; other mammals can occasionally become infected.
Influenza vaccines, colloquially known as flu shots, are vaccines that protect against infection by influenza viruses. New versions of the vaccines are developed twice a year, as the influenza virus rapidly changes. While their effectiveness varies from year to year, most provide modest to high protection against influenza. Vaccination against influenza began in the 1930s, with large-scale availability in the United States beginning in 1945.
Swine influenza is an infection caused by any of several types of swine influenza viruses. Swine influenza virus (SIV) or swine-origin influenza virus (S-OIV) refers to any strain of the influenza family of viruses that is endemic in pigs. As of 2009, identified SIV strains include influenza C and the subtypes of influenza A known as H1N1, H1N2, H2N1, H3N1, H3N2, and H2N3.
In virology, influenza A virus subtype H1N1 (A/H1N1) is a subtype of influenza A virus. Major outbreaks of H1N1 strains in humans include the 1918 Spanish flu pandemic, the 1977 Russian flu pandemic and the 2009 swine flu pandemic. It is an orthomyxovirus that contains the glycoproteins hemagglutinin (H) and neuraminidase (N), antigens whose subtypes are used to classify the strains of the virus as H1N1, H1N2 etc. Hemagglutinin causes red blood cells to clump together and binds the virus to the infected cell. Neuraminidase is a type of glycoside hydrolase enzyme which helps to move the virus particles through the infected cell and assist in budding from the host cells.
An influenza pandemic is an epidemic of an influenza virus that spreads across a large region and infects a large proportion of the population. There have been six major influenza epidemics in the last 140 years, with the 1918 flu pandemic being the most severe; this is estimated to have been responsible for the deaths of 50–100 million people. The 2009 swine flu pandemic resulted in under 300,000 deaths and is considered relatively mild. These pandemics occur irregularly.
Influenza A virus subtype H3N2 (A/H3N2) is a subtype of viruses that causes influenza (flu). H3N2 viruses can infect birds and mammals. In birds, humans, and pigs, the virus has mutated into many strains. In years in which H3N2 is the predominant strain, there are more hospitalizations.
The 2009 swine flu pandemic, caused by the H1N1/swine flu/influenza virus and declared by the World Health Organization (WHO) from June 2009 to August 2010, was the third recent flu pandemic involving the H1N1 virus. The first identified human case was in La Gloria, Mexico, a rural town in Veracruz. The virus appeared to be a new strain of H1N1 that resulted from a previous triple reassortment of bird, swine, and human flu viruses which further combined with a Eurasian pig flu virus, leading to the term "swine flu".
The 2009 swine flu pandemic in Canada was part of an epidemic in 2009 of a new strain of influenza A virus subtype H1N1 causing what has been commonly called swine flu. In Canada, roughly 10% of the populace has been infected with the virus, with 428 confirmed deaths ; non-fatal individual cases are for the most part no longer being recorded. About 40% of Canadians have been immunized against H1N1 since a national vaccination campaign began in October 2009, with Canada among the countries in the world leading in the percentage of the population that has been vaccinated. The widespread effect of H1N1 in Canada raised concerns during the months leading to the XXI Olympic Winter Games, which took place in Vancouver in February 2010.
This article covers the chronology of the 2009 novel influenza A (H1N1) pandemic. Flag icons denote the first announcements of confirmed cases by the respective nation-states, their first deaths, and relevant sessions and announcements of the World Health Organization (WHO), the European Union , and the U.S. Centers for Disease Control (CDC).
In March and April 2009, an outbreak of a new strain of influenza commonly referred to as "swine flu" infected many people in Mexico and other parts of the world, causing illness ranging from mild to severe. Initial reports suggested that the outbreak had started in February due to farming practices at a pig farm half-owned by Smithfield Foods. Smithfield Foods stated that it had found no clinical signs or symptoms of the presence of swine influenza in the company's swine herd, or among its employees at its joint ventures in Mexico, that it routinely administers influenza virus vaccination to their swine herds and that it conducts monthly testing for the presence of swine influenza. The new strain was identified as a combination of several different strains of Influenzavirus A, subtype H1N1, including separate strains of this subtype circulating in humans and in pigs.
The 2009 swine flu pandemic was a global outbreak of a new strain of influenza A virus subtype H1N1, first identified in April 2009, termed Pandemic H1N1/09 virus by the World Health Organization (WHO) and colloquially called swine flu. The outbreak was first observed in Mexico, and quickly spread globally. On 11 June 2009, the WHO declared the outbreak to be a pandemic. The overwhelming majority of patients experienced mild symptoms, but some persons were in higher risk groups, such as those with asthma, diabetes, obesity, heart disease, who were pregnant or had a weakened immune system. In the rare severe cases, around 3–5 days after symptoms manifest, the sufferer's condition declines quickly, often to the point of respiratory failure.
Australia had 37,537 confirmed cases of H1N1 Influenza 2009 and 191 deaths reported by Department of Health but only 77 deaths reported by the Australian Bureau of Statistics. The actual numbers are much larger, as only serious cases warranted being tested and treated at the time. Suspected cases have not been reported by the Department of Health and Ageing since 18 May 2009 because they were changing too quickly to report. Sources say that as many as 1600 Australians may have actually died as a result of this virus. On 23rd of May 2009 the federal government classified the outbreak as CONTAIN phase except in Victoria where it was escalated to the SUSTAIN phase on 3rd of June 2009. This gave government authorities permission to close schools in order to slow the spread of the disease. On 17 June 2009 the Department of Health and Ageing introduced a new phase called PROTECT. This modified the response to focus on people with high risk of complications from the disease. Testing at airports was discontinued. The national stockpile of antiviral drugs were no longer made available to people with the flu unless there were more than mild symptoms or a high risk of dying.
This article deals with the status and efforts regarding the 2009 swine flu pandemic by country and continent/region.
The pandemic H1N1/09 virus is a swine origin influenza A virus subtype H1N1 strain that was responsible for the 2009 swine flu pandemic. This strain is often called swine flu by the public media due to the prevailing belief that it originated in pigs. The virus is believed to have originated around September 2008 in central Mexico.
The 2009 flu pandemic in Asia, part of an epidemic in 2009 of a new strain of influenza A virus subtype H1N1 causing what has been commonly called swine flu, afflicted at least 394,133 people in Asia with 2,137 confirmed deaths: there were 1,035 deaths confirmed in India, 737 deaths in China, 415 deaths in Turkey, 192 deaths in Thailand, and 170 deaths in South Korea. Among the Asian countries, South Korea had the most confirmed cases, followed by China, Hong Kong, and Thailand.
The 2009 swine flu pandemic in North America, part of a pandemic in 2009 of a new strain of influenza A virus subtype H1N1 causing what has been commonly called swine flu, began in the United States or Mexico.
The 2009 swine flu pandemic vaccines were influenza vaccines developed to protect against the pandemic H1N1/09 virus. These vaccines either contained inactivated (killed) influenza virus, or weakened live virus that could not cause influenza. The killed virus was injected, while the live virus was given as a nasal spray. Both these types of vaccine were produced by growing the virus in chicken eggs. Around three billion doses were produced, with delivery in November 2009.
The United States experienced the beginnings of a pandemic of a novel strain of the influenza A/H1N1 virus, commonly referred to as "swine flu", in the spring of 2009. The earliest reported cases in the US began appearing in late March 2009 in California, then spreading to infect people in Texas, New York, and other states by mid-April. Early cases were associated with recent travel to Mexico; many were students who had traveled to Mexico for Spring Break. This spread continued across the country's population and by the end of May there were approximately 0 confirmed cases throughout all 50 states.
The 2009 swine flu pandemic was a global outbreak of a new strain of influenza A virus subtype H1N1, first identified in April 2009, termed Pandemic H1N1/09 virus by the World Health Organization (WHO) and colloquially called swine flu. The outbreak was first observed in Mexico, and quickly spread globally. On 11 June 2009, WHO declared the outbreak to be a pandemic. The overwhelming majority of patients experience mild symptoms", but some persons are in higher risk groups, such as those with asthma, diabetes, obesity, heart disease, or who are pregnant or have a weakened immune system. In the rare severe cases, around 3–5 days after symptoms manifest, the person's condition declines quickly, often to the point respiratory failure.
2009 swine flu pandemic in Taiwan began on May 20, 2009, when a non-citizen who had been living in Taiwan returned from the United States via Hong Kong. By the end of September, more than 90% of influenza A detected in the community were Influenza A (H1N1).
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: CS1 maint: bot: original URL status unknown (link)Reporting of aggregate statistics ended between 21 and 28 October, 2009 were "impractical because of the large number of people infected." (quote from )updated September 2, 2009 at 12:00 PM
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: CS1 maint: bot: original URL status unknown (link)...(n=1,103)...from September 1, 2009 through April 6, 2010
Pandemic (H1N1) 2009 influenza A information for July 20, 2010
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: CS1 maint: bot: original URL status unknown (link)Illinois Cases of H1N1 Flu by County (As of July 31, 2009, 10 a.m.)
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: CS1 maint: bot: original URL status unknown (link)Confirmed H1N1 2009 Hospitalizations and Deaths (As of May 7, 2010, 10 a.m.)
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