Influenza A virus (IAV) causes influenza in birds and some mammals, and is the only species of the genus Alphainfluenzavirus of the virus family Orthomyxoviridae. Strains of all subtypes of influenza A virus have been isolated from wild birds, although disease is uncommon. Some isolates of influenza A virus cause severe disease both in domestic poultry and, rarely, in humans. Occasionally, viruses are transmitted from wild aquatic birds to domestic poultry, and this may cause an outbreak or give rise to human influenza pandemics.
Avian influenza, known informally as avian flu or bird flu, is a variety of influenza caused by viruses adapted to birds. The type with the greatest risk is highly pathogenic avian influenza (HPAI). Bird flu is similar to swine flu, dog flu, horse flu and human flu as an illness caused by strains of influenza viruses that have adapted to a specific host. Out of the three types of influenza viruses, influenza A virus is a zoonotic infection with a natural reservoir almost entirely in birds. Avian influenza, for most purposes, refers to the influenza A virus.
Influenza A virus subtype H5N1 (A/H5N1) is a subtype of the influenza A virus which can cause illness in humans and many other animal species. A bird-adapted strain of H5N1, called HPAI A(H5N1) for highly pathogenic avian influenza virus of type A of subtype H5N1, is the highly pathogenic causative agent of H5N1 flu, commonly known as avian influenza. It is enzootic in many bird populations, especially in Southeast Asia. One strain of HPAI A(H5N1) is spreading globally after first appearing in Asia. It is epizootic and panzootic, killing tens of millions of birds and spurring the culling of hundreds of millions of others to stem its spread. Many references to "bird flu" and H5N1 in the popular media refer to this strain.
In virology, influenza A virus subtype H1N1 (A/H1N1) is a subtype of Influenza A virus. Well known outbreaks of H1N1 strains in humans include the Spanish flu, the 1977 Russian flu pandemic and the 2009 swine flu pandemic. It is an orthomyxovirus that contains the glycoproteins hemagglutinin and neuraminidase. For this reason, they are described as H1N1, H1N2 etc., depending on the type of H or N antigens they express with metabolic synergy. 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.
The Pandemic Preparedness and Response Act is a bill introduced on October 5, 2005, by U.S. Senators Harry Reid, Evan Bayh, Dick Durbin, Ted Kennedy, Barack Obama, and Tom Harkin in response to the growing threat of an outbreak of avian influenza. The bill calls for:
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 most recent, the 2009 swine flu pandemic, resulted in under 300,000 deaths and is considered relatively mild. These pandemics occur irregularly.
The European Centre for Disease Prevention and Control (ECDC) is an agency of the European Union (EU) whose mission is to strengthen Europe's defences against infectious diseases. It covers a wide spectrum of activities, such as: surveillance, epidemic intelligence, response, scientific advice, microbiology, preparedness, public health training, international relations, health communication, and the scientific journal Eurosurveillance.
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.
Transmission and infection of H5N1 from infected avian sources to humans has been a concern since the first documented case of human infection in 1997, due to the global spread of H5N1 that constitutes a pandemic threat.
Influenza A virus subtype H7N7 (A/H7N7) is a subtype of Influenza A virus, a genus of Orthomyxovirus, the viruses responsible for influenza. Highly pathogenic strains (HPAI) and low pathogenic strains (LPAI) exist. H7N7 can infect humans, birds, pigs, seals, and horses in the wild; and has infected mice in laboratory studies. This unusual zoonotic potential represents a pandemic threat.
Disease surveillance is an epidemiological practice by which the spread of disease is monitored in order to establish patterns of progression. The main role of disease surveillance is to predict, observe, and minimize the harm caused by outbreak, epidemic, and pandemic situations, as well as increase knowledge about which factors contribute to such circumstances. A key part of modern disease surveillance is the practice of disease case reporting.
OFFLU is the joint OIE-FAO global network of expertise on animal influenzas. OFFLU aims to reduce negative impacts of animal influenza viruses by promoting effective collaboration between animal health experts and with the human health sector. OFFLU analyses and shares information and biological material to identify and reduce health threats early, and shares information about animal influenza viruses with the World Health Organization (WHO) to assist with the early preparation of human vaccines. It was established in 2005, initially to support the global effort to control H5N1 highly pathogenic avian influenza.
The global spread of H5N1 in birds is considered a significant pandemic threat.
The global spread of H5N1 in birds is considered a significant pandemic threat.
The global spread of H5N1 in birds is considered a significant pandemic threat.
GISAID is a global science initiative and primary source established in 2008 that provides open access to genomic data of influenza viruses and the coronavirus responsible for the COVID-19 pandemic. On January 10, 2020, the first whole-genome sequences of SARS-CoV-2 were made available on GISAID, which enabled global responses to the pandemic, including the development of the first vaccines and diagnostic tests to detect SARS-CoV-2. The database has become the world's largest repository for SARS-CoV-2 sequences. GISAID facilitates genomic epidemiology and real-time surveillance to monitor the emergence of new COVID-19 viral strains across the planet.
Human mortality from H5N1 or the human fatality ratio from H5N1 or the case-fatality rate of H5N1 is the ratio of the number of confirmed human deaths resulting from confirmed cases of transmission and infection of H5N1 to the number of those confirmed cases. For example, if there are 100 confirmed cases of humans infected with H5N1 and 10 die, then there is a 10% human fatality ratio. H5N1 flu is a concern due to the global spread of H5N1 that constitutes a pandemic threat. The majority of H5N1 flu cases have been reported in southeast and east Asia. The case-fatality rate is central to pandemic planning. Estimates of case-fatality (CF) rates for past influenza pandemics have ranged from to 2-3% for the 1918 pandemic to about 0.6% for the 1957 pandemic to 0.2% for the 1968 pandemic. As of 2008, the official World Health Organization estimate for the case-fatality rate for the outbreak of H5N1 avian influenza was approximately 60%. Public health officials in Ontario, Canada argue that the true case-fatality rate could be lower, pointing to studies suggesting it could be 0-1%, but warned that it was unlikely to be as low as the 0.1–0.4% rate that was built into many pandemic plans.
H2N3 is a subtype of the influenza A virus. Its name derives from the forms of the two kinds of proteins on the surface of its coat, hemagglutinin (H) and neuraminidase (N). H2N3 viruses can infect birds and mammals.
This is a timeline of influenza, briefly describing major events such as outbreaks, epidemics, pandemics, discoveries and developments of vaccines. In addition to specific year/period-related events, there's the seasonal flu that kills between 250,000 and 500,000 people every year, and has claimed between 340 million and 1 billion human lives throughout history.
Health security is a concept that encompasses activities and measures across sovereign boundaries that mitigates public health incidents to ensure the health of populations. It is an evolving paradigm within the fields of international relations and security studies. Proponents of health security posit that all states have a responsibility to protect the health and wellbeing of their populations. Opponents suggest health security impacts civil liberties and the equal distribution of resources.