The Global Influenza Surveillance and Response System (GISRS) is a global network of laboratories that has the purpose to monitor the spread of influenza with the aim to provide the World Health Organization with influenza control information. [1] It was established in 1952 to conduct global influenza surveillance and to inform vaccine development. [2] GISRS is coordinated by WHO and endorsed by national governments. Several millions of respiratory specimens are tested by GISRS annually to monitor the spread and evolution of influenza viruses through a network of laboratories in 127 countries representing 91% of the world's population. [3] [4] As well as human viruses, GISRS monitors avian and other potentially zoonotic influenza viruses. [5] GISRS operates FluNet, an online tool used for virological surveillance of influenza. [1]
In addition to the influenza pandemics of 1957, 1968 and 2009, GISRS has coordinated the world’s response to episodic human cases of infection with the avian influenza A(H5N1) virus since 1997, the first outbreaks of severe acute respiratory syndrome (SARS) in 2002, and the Middle East respiratory syndrome (MERS) in 2012 in some countries. [4]
In 1947, the WHO Interim Committee of the United Nations agreed to begin a Global Influenza Programme (GIP) for the study and control of influenza. A major outbreak of influenza in Europe was an immediate concern, as well as the identification of appropriate viruses for a vaccine against the virus strains which might be circulating. The establishment of regional influenza centers began in 1948. Five years after the creation of GIP, the Global Influenza Surveillance Network (GISN) was established in response to a need for an influenza surveillance system to inform the methods for disease prevention and control. GISN would later be renamed Global Influenza Surveillance and Response System (GISRS), [6] evolving as an integrated scientific and technical global collaboration to fulfil the objectives and activities of GIP. [7] GISRS gained momentum between the 1957 and 1968 pandemics. The growing network of national influenza centers focused on understanding disease activity and characteristics of influenza viruses globally. Through these efforts, the realization that the viruses were not only present in tropical countries but might circulate for much of the year was confirmed. [8]
As of 2015, GISRS comprised 142 national influenza centers in 115 countries, [9] 6 WHO collaborating centers, 4 WHO essential regulatory laboratories, and 13 WHO H5 reference laboratories. [10]
GISRS is considered an "effective early warning system" for changes in influenza viruses circulating in the global population, which helps mitigate the consequences of a pandemic and maintain the efficacy of seasonal influenza vaccines. [11]
A pandemic is an epidemic of an infectious disease that has a sudden increase in cases and spreads across a large region, for instance multiple continents or worldwide, affecting a substantial number of individuals. Widespread endemic diseases with a stable number of infected individuals such as recurrences of seasonal influenza are generally excluded as they occur simultaneously in large regions of the globe rather than being spread worldwide.
A zoonosis or zoonotic disease is an infectious disease of humans caused by a pathogen that can jump from a non-human to a human and vice versa.
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.
Avian influenza, also known as avian flu or bird flu, is a disease caused by the influenza A virus, which primarily affects birds but can sometimes affect mammals including humans. Wild aquatic birds are the primary host of the influenza A virus, which is enzootic in many bird populations.
Influenza A virus subtype H5N1 (A/H5N1) is a subtype of the influenza A virus, which causes influenza (flu), predominantly in birds. It is enzootic in many bird populations, and also panzootic. A/H5N1 virus can also infect mammals that have been exposed to infected birds; in these cases, symptoms are frequently severe or fatal.
The Hong Kong flu, also known as the 1968 flu pandemic, was a flu pandemic that occurred in 1968 and 1969 and which killed between one and four million people globally. It is among the deadliest pandemics in history, and was caused by an H3N2 strain of the influenza A virus. The virus was descended from H2N2 through antigenic shift, a genetic process in which genes from multiple subtypes are reassorted to form a new virus.
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.
Influenza A virus subtype H1N1 (A/H1N1) is a subtype of influenza A virus (IAV). Some human-adapted strains of H1N1 are endemic in humans and are one cause of seasonal influenza (flu). Other strains of H1N1 are endemic in pigs and in birds. Subtypes of IAV are defined by the combination of the antigenic H and N proteins in the viral envelope; for example, "H1N1" designates an IAV subtype that has a type-1 hemagglutinin (H) protein and a type-1 neuraminidase (N) protein.
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 influenza A virus (IAV). Some human-adapted strains of A/H3N2 are endemic in humans and are one cause of seasonal influenza (flu). Other strains of H1N1 are endemic in pigs and in birds. Subtypes of IAV are defined by the combination of the antigenic H and N proteins in the viral envelope; for example, "H1N1" designates an IAV subtype that has a type-1 hemagglutinin (H) protein and a type-1 neuraminidase (N) protein.
An emergent virus is a virus that is either newly appeared, notably increasing in incidence/geographic range or has the potential to increase in the near future. Emergent viruses are a leading cause of emerging infectious diseases and raise public health challenges globally, given their potential to cause outbreaks of disease which can lead to epidemics and pandemics. As well as causing disease, emergent viruses can also have severe economic implications. Recent examples include the SARS-related coronaviruses, which have caused the 2002–2004 outbreak of SARS (SARS-CoV-1) and the 2019–2023 pandemic of COVID-19 (SARS-CoV-2). Other examples include the human immunodeficiency virus, which causes HIV/AIDS; the viruses responsible for Ebola; the H5N1 influenza virus responsible for avian influenza; and H1N1/09, which caused the 2009 swine flu pandemic. Viral emergence in humans is often a consequence of zoonosis, which involves a cross-species jump of a viral disease into humans from other animals. As zoonotic viruses exist in animal reservoirs, they are much more difficult to eradicate and can therefore establish persistent infections in human populations.
The genetic structure of H5N1, a highly pathogenic avian influenza virus, is characterized by a segmented RNA genome consisting of eight gene segments that encode for various viral proteins essential for replication, host adaptation, and immune evasion.
GISAID, the Global Initiative on Sharing All Influenza Data, previously the Global Initiative on Sharing Avian Influenza Data, is a global science initiative established in 2008 to provide access to genomic data of influenza viruses. The database was expanded to include the coronavirus responsible for the COVID-19 pandemic, as well as other pathogens. The database has been described as "the world's largest repository of COVID-19 sequences". GISAID facilitates genomic epidemiology and real-time surveillance to monitor the emergence of new COVID-19 viral strains across the planet.
The National Institute of Virology in Pune, India is an Indian virology research institute and part of the Indian Council of Medical Research (ICMR). It was previously known as 'Virus Research Centre' and was founded in collaboration with the Rockefeller Foundation. It has been designated as a WHO H5 reference laboratory for SE Asia region.
Influenza, commonly known as "the flu" or just "flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin one to four days after exposure to the virus and last for about two to eight days. Diarrhea and vomiting can occur, particularly in children. Influenza may progress to pneumonia from the virus or a subsequent bacterial infection. Other complications include acute respiratory distress syndrome, meningitis, encephalitis, and worsening of pre-existing health problems such as asthma and cardiovascular disease.
Influenza A virus subtype H7N9 (A/H7N9) is a subtype of the influenza A virus, which causes influenza (flu), predominantly in birds. It is enzootic in many bird populations. The virus can spread rapidly through poultry flocks and among wild birds; it can also infect humans that have been exposed to infected birds.
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 is 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.
Arnold Monto is an American physician and epidemiologist. At the University of Michigan School of Public Health, Monto is the Thomas Francis, Jr. Collegiate Professor Emeritus of Public Health, professor emeritus of both epidemiology and global public health, and co-director of the Michigan Center for Respiratory Virus Research & Response. His research focuses on the occurrence, prevention, and treatment of viral respiratory infections in industrialized and developing countries' populations.
The 1957–1958 Asian flu pandemic was a global pandemic of influenza A virus subtype H2N2 that originated in Guizhou in Southern China. The number of excess deaths caused by the pandemic is estimated to be 1–4 million around the world, making it one of the deadliest pandemics in history. A decade later, a reassorted viral strain H3N2 further caused the Hong Kong flu pandemic (1968–1969).
The Global Influenza Programme (GIP) is a program launched in 1947 by the World Health Organization with the purpose to provide member states with guidance, support and coordination of activities in order to make their health systems better prepared against seasonal, zoonotic and pandemic influenza threats to populations and individuals. GIP was initiated as one of WHO's initial programs.