However, avian influenza is very contagious among birds and can make some domesticated birds, comprising chickens, ducks, and turkeys, very sick and kill them. Infected birds shed flu virus in their saliva, nasal secretions, and feces. Susceptible birds become infected when they gets contacted with contaminated secretions or excretions or with surfaces that are contaminated with secretions or excretions from infected birds.

Domesticated birds may become infected with avian influenza virus through direct contact with infected waterfowl or other infected poultry, or through contact with surfaces or materials like that of water or feed that have been contaminated with the virus.

Types of bird flu disease

Infection with avian influenza viruses in domestic poultry causes two main forms of disease that are famed by low and high extremes of virulence. The low pathogenic form might go undetected and usually causes only mild symptoms. However, the highly pathogenic form spreads more speedily through flocks of poultry.

This form might cause disease that affects multiple internal organs and has a mortality rate that can reach 90-100% often within 48 hours. There are many different sub-types of type A influenza viruses. These subtypes vary because of changes in certain proteins on the surface of the influenza A virus.

There are 16 known HA sub-types and 9 called as NA sub-types of influenza A viruses. Many different combinations of HA and NA proteins are probable. Each combination presents a different sub-type. All are known as subtypes of influenza A viruses can be found in birds.

Symptoms of bird flu symptoms

Generally, avian influenza virus refers to influenza A viruses found chiefly in birds, but infections with these viruses can take place in humans. The risk from avian influenza is usually low to most people, because the viruses do not generally infect humans. However, confirmed cases of human infection from numerous subtypes of avian influenza infection have been reported since 1997.

Most cases of bird influenza infection in humans have resulted from contact with infected poultry or surfaces contaminated with secretion and excretions from infected birds. The spread of bird influenza viruses from one ill person to another has been reported very seldom, and transmission has not been observed to continue beyond one person. Symptoms of bird influenza in humans have ranged from typical human influenza-like symptoms, and other serious and life-threatening complications. The symptoms of bird influenza might depend on which virus caused the infection.