The 1918–1920 flu pandemic, also known as the Great Influenza epidemic or by the common misnomer Spanish flu, was an exceptionally deadly global influenza pandemic caused by the H1N1 influenza A virus. The earliest documented case was March 1918 in the state of Kansas in the United States, with further cases recorded in France, Germany and the United Kingdom in April. Two years later, nearly a third of the global population, or an estimated 500 million people, had been infected in four successive waves. Estimates of deaths range from 17 million to 50 million, and possibly as high as 100 million, making it one of the deadliest pandemics in history.
Influenza A virus (IAV) is a pathogen that causes the flu in birds and some mammals, including humans. It is an RNA virus whose subtypes have been isolated from wild birds. Occasionally, it is transmitted from wild to domestic birds, and this may cause severe disease, outbreaks, or human influenza pandemics.
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.
The global spread of H5N1 influenza in birds is considered a significant pandemic threat. While other H5N1 influenza strains are known, they are significantly different on a genetic level from a recent, highly pathogenic, emergent strain of H5N1, which was able to achieve hitherto unprecedented global spread in 2008. The H5N1 strain is a fast-mutating, highly pathogenic avian influenza virus (HPAI) found in multiple bird species. It is both epizootic and panzootic. Unless otherwise indicated, "H5N1" in this timeline refers to the recent highly pathogenic strain of H5N1.
Thiomersal is a mercury compound which is used as a preservative in some vaccines. Anti-vaccination activists promoting the incorrect claim that vaccination causes autism have asserted that the mercury in thiomersal is the cause. There is no scientific evidence to support this claim. The idea that thiomersal in vaccines might have detrimental effects originated with anti-vaccination activists and was sustained by them and especially through the action of plaintiffs' lawyers.
The social impact of H5N1 is the effect or influence of H5N1 in human society, especially the financial, political, social, and personal responses to both actual and predicted deaths in birds, humans, and other animals. Billions of dollars are raised and spent to research H5N1 and prepare for a potential avian influenza pandemic. Over ten billion dollars were lost, and over two hundred million birds were killed to contain H5N1. People reacted by buying less chicken causing poultry sales and prices to fall. Many individuals stockpiled supplies for a possible flu pandemic.
The elbow bump is an informal greeting where two people touch elbows. Interest in this greeting was renewed during the avian flu scare of 2006, the 2009 swine flu pandemic, the Ebola outbreak of 2014, and the COVID-19 pandemic when health officials supported its use as an alternative to hand-shaking to reduce the spread of germs. During the latter pandemic, authorities advised that even an elbow bump was too risky, and suggested greeting from a distance.
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 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. While the 2009 H1N1 virus strain was commonly referred to as "swine flu", there is no evidence that it is endemic to pigs or of transmission from pigs to people; instead, the virus spreads from person to person. On April 25, the World Health Organization declared a public health emergency, followed concurringly by the Obama administration on April 26.
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).
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.
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. For other names, see the Nomenclature section below.
The 2009 flu pandemic in Oceania, part of an epidemic in 2009 of a new strain of influenza A virus subtype H1N1 causing what has been commonly called swine flu, has afflicted at over 22,000 people in Oceania, with 56 confirmed deaths. Almost all of the cases in Oceania have been in Australia, where the majority of cases have resulted from internal community spread of the virus. In addition, the government of New Zealand, where most of the remainder of cases in Oceania have occurred, is on high alert for any people travelling into the country with flu-like symptoms.
The 2009 swine flu pandemic in New Zealand was caused by a novel strain of the A/H1N1 influenza virus. A total of 3,175 cases and 69 deaths were recorded, although a seroprevalence study estimated that around 800,000 individuals may have been infected during the initial wave of the pandemic.
Big Pharma conspiracy theories are conspiracy theories which claim that pharmaceutical companies, especially large corporations, act in sinister and secretive ways, such as concealing effective treatments, or even intentionally causing and worsening a wide range of diseases, in pursuit of profitability, or for other nefarious reasons. Some theories have included the claim that natural alternative remedies to health problems are being suppressed, the claim that drugs for the treatment of HIV/AIDS are ineffective and harmful, the claim that a cure for all cancers has been discovered but hidden from the public, claims that COVID-19 vaccines are ineffective, and that alternative cures are available for COVID-19. In most cases the conspiracy theorists have blamed pharmaceutical companies' search for profits. A range of authors have shown these claims to be false, though some of these authors nevertheless maintain that other criticisms of the pharmaceutical industry are legitimate.
Planning and preparing for pandemics has happened in countries and international organizations. The World Health Organization writes recommendations and guidelines, though there is no sustained mechanism to review countries' preparedness for epidemics and their rapid response abilities. National action depends on national governments. In 2005–2006, before the 2009 swine flu pandemic and during the decade following it, the governments in the United States, France, UK, and others managed strategic health equipment stocks, but they often reduced stocks after the 2009 pandemic in order to reduce costs.
In the waning months of 2022, the first northern hemisphere autumn with the nearly full relaxation of public health precautions related to the COVID-19 pandemic, hospitals in the United States and Canada began to see overwhelming numbers of pediatric care patients, primarily driven by a massive upswing in respiratory syncytial virus (RSV) cases, but also flu, rhinovirus, enterovirus, and SARS-CoV-2.
