Influenza A virus subtype H9N2

Influenza A virus subtype H9N2 is a subtype of the Influenza A virus, which is part of the Orthomyxoviridae family. This subtype is known to infect birds, pigs, and humans, and is considered a potential candidate for a new influenza pandemic.

Overview

Influenza A virus subtype H9N2 is an avian influenza virus that has been isolated from a wide variety of bird species. The virus was first identified in the United States in 1966 from turkeys exhibiting a mild respiratory disease. Since then, H9N2 viruses have been detected and isolated worldwide in wild birds, poultry, pigs, and humans.

Infection in Birds

In birds, H9N2 viruses can cause mild to severe disease, ranging from mild respiratory symptoms and drop in egg production to severe respiratory disease and high mortality. The virus is transmitted between birds through direct contact, airborne transmission, and through contaminated water or feed.

Infection in Humans

Human infections with H9N2 have been reported in several countries, including China, Hong Kong, Bangladesh, Pakistan, and Egypt. Most human infections with H9N2 have been mild, with symptoms including fever, cough, sore throat, and sometimes pneumonia. However, severe and fatal infections have also been reported, particularly in people with underlying health conditions.

Prevention and Control

Vaccination is the primary method for controlling H9N2 in poultry. However, the virus can mutate rapidly, leading to the emergence of new strains that may not be covered by existing vaccines. Therefore, continuous surveillance and rapid response to outbreaks are crucial for the control of H9N2.

Research

Research on H9N2 is ongoing to better understand its epidemiology, pathogenesis, and potential for human-to-human transmission. This research is crucial for the development of effective vaccines and antiviral drugs, and for the preparation of pandemic influenza plans.

See Also

• Influenza A virus
• Influenza pandemic
• Avian influenza
• Influenza vaccine