Influenza A

Influenza is a pleomorphic, enveloped, single-stranded RNA virus of the family Orthomyxoviridae. There are four subtypes: Genus Influenzavirus A, Genus Influenzavirus B, Genus Influenzavirus C, and Genus "Tthogoto-like Viruses." Influenza A and B cause epidemics of respiratory illness in humans and animals. Animal hosts include: birds, pigs, ducks, whales, horses, and seals.

Variations in the two surface proteins of influenza A, hemagglutinin (H) and neuraminidase (N), are used to describe specific viruses. At least 15 types of hemagglutinin and 9 types of neuraminidase are recognized, although not all forms are seen in human infections.

Graphic from American Health Consultants web site

Significant change in these proteins is often associated with epidemics. Worldwide epidemics occur when changes to these proteins are marked, such as when a form of influenza A only seen in animals suddenly begins to infect humans.

Human vaccines against influenza A & B are annually designed to protect against the threat of changes in endemic influenza strains.

In recent years, influenza strains normally only detected in birds (H5N1 and H9N2) have caused disease in humans. The cross-species movement of influenza merits close surveillance.

The following web sites contain detailed information regarding influenza:

CDC

The Big Picture Book of Viruses: Orthomyxoviridae

All the Virology on the Web


College of Public Health

Virus Safety and Food

The virus is inactivated at temperatures reached during conventional cooking practices (at least 70° C at the centre of the product (“piping” hot) or when the meat is not pink in any part). Consumption of properly cooked poultry is safe. It should therefore be emphasized that consumption of any raw poultry ingredients must be considered a high-risk practice and discouraged.

Influenza
 an acute febrile highly contagious viral disease