H9N2

Influenza A virus subtype H7N7 is a subtype of the species Influenza A virus. This subtype is known to infect both birds and mammals, including humans, and has been associated with outbreaks of influenza in poultry and humans.

Virology

The H7N7 virus is an orthomyxovirus, which is a family of RNA viruses. The virus has a segmented, negative-sense RNA genome. The "H" in H7N7 stands for hemagglutinin type 7, and the "N" stands for neuraminidase type 7. These are two proteins on the surface of the virus that are critical for its ability to infect host cells and spread.

Hemagglutinin (HA)

The hemagglutinin protein is responsible for binding the virus to the cell that is being infected. It recognizes and binds to sialic acid residues on the surface of the host cell. The H7 subtype is one of several hemagglutinin subtypes found in influenza viruses.

Neuraminidase (NA)

The neuraminidase protein helps the virus to be released from the host cell after replication. It cleaves sialic acid residues, allowing the newly formed viral particles to escape and infect other cells.

Epidemiology

H7N7 has been isolated from a variety of avian species, and it has been responsible for several outbreaks in poultry. Notably, an outbreak in the Netherlands in 2003 resulted in the culling of millions of birds and also led to human infections.

Human Infections

Human infections with H7N7 are rare but can occur, particularly in individuals who have close contact with infected birds. Symptoms in humans can range from mild conjunctivitis to severe respiratory illness. There is concern about the potential for H7N7 to acquire mutations that could facilitate human-to-human transmission.

Prevention and Control

Control measures for H7N7 outbreaks in poultry include culling of infected and exposed birds, vaccination, and biosecurity measures to prevent the spread of the virus. For humans, personal protective equipment and antiviral medications may be used to prevent infection in those exposed to the virus.

Research

Ongoing research is focused on understanding the molecular mechanisms of H7N7 pathogenicity and transmission, as well as developing effective vaccines and antiviral drugs.

Also see

• Influenza A virus subtype H5N1
• Influenza A virus subtype H1N1
• Influenza pandemic
• Zoonosis