Which Virus Causes Bird Flu?

Bird flu, also known as avian influenza, is caused by several subtypes of influenza A viruses that primarily affect birds, including wild birds and domestic poultry. The avian influenza viruses belong to the Influenza A virus family, and some of them have the potential to infect humans. The most well-known avian influenza virus subtypes that have caused concern are H5N1 and H7N9.

  • H5N1: Highly pathogenic avian influenza (HPAI) H5N1 is one of the most widely known bird flu viruses. It has caused outbreaks in domestic poultry and wild birds in multiple countries. H5N1 has also been responsible for sporadic cases of human infection, often with severe illness and a high mortality rate. Human infections with H5N1 have typically been associated with close contact with infected poultry.
  • H7N9: Influenza A H7N9 is another avian influenza virus that has caused concern. It has caused outbreaks in poultry and has led to human infections in several countries, primarily in China. H7N9 infections in humans have been associated with live poultry markets and exposure to infected birds.

It’s important to note that while avian influenza viruses can infect humans, sustained human-to-human transmission is rare. Most cases of avian influenza in humans have resulted from direct or close contact with infected birds. Public health measures, including monitoring and control of outbreaks in poultry, as well as surveillance and rapid response to human cases, are crucial for preventing the spread of bird flu.

Influenza A viruses are known for their ability to mutate and potentially reassort, which can lead to the emergence of new strains. These changes in the virus can pose challenges in managing and preventing avian influenza. Public health agencies and authorities closely monitor avian influenza viruses to detect and respond to potential threats to human health.