Avian Flu

Avian Influenza

Avian influenza, commonly known as bird flu, is an infectious viral disease of birds, particularly wild waterfowl such as ducks and geese. It can also infect domestic poultry and other bird and animal species. Some strains of avian influenza can infect humans, posing a significant public health concern.

Virology

Avian influenza is caused by viruses of the family Orthomyxoviridae, genus Influenza virus A. These viruses are classified into subtypes based on two proteins on the surface of the virus: hemagglutinin (HA) and neuraminidase (NA). There are 18 different HA subtypes and 11 different NA subtypes, leading to a variety of combinations such as H5N1, H7N9, and H9N2.

Transmission

The primary mode of transmission of avian influenza among birds is through direct contact with infected birds, their droppings, or contaminated water and feed. The virus can also spread through the air in droplets or dust. In humans, infection can occur through direct or close contact with infected birds or contaminated environments.

Symptoms

In birds, symptoms of avian influenza can range from mild to severe and may include ruffled feathers, decreased egg production, respiratory distress, and high mortality rates. In humans, symptoms can range from typical flu-like symptoms such as fever, cough, sore throat, and muscle aches to severe respiratory illness and even death.

Diagnosis

Diagnosis of avian influenza in birds and humans is typically confirmed through laboratory tests, including reverse transcription polymerase chain reaction (RT-PCR), virus isolation, and serological tests.

Prevention and Control

Preventive measures for avian influenza include biosecurity practices in poultry farms, vaccination of poultry, and monitoring and surveillance of wild and domestic birds. In humans, preventive measures include avoiding contact with infected birds and practicing good hygiene.

Treatment

In humans, antiviral medications such as oseltamivir (Tamiflu) and zanamivir (Relenza) can be used to treat avian influenza, although their effectiveness may vary depending on the strain of the virus.

Public Health Impact

Avian influenza poses a significant threat to public health due to its potential to cause pandemics. The H5N1 and H7N9 strains have been of particular concern due to their high mortality rates in humans and potential for human-to-human transmission.

Also see

• Influenza
• Zoonosis
• Pandemic
• Viral Hemagglutinin
• Neuraminidase