Avian Flu Signs and Symptoms: An Overview
Avian flu (also called
avian influenza or
bird flu) is an infection caused by avian flu viruses. These flu viruses occur naturally among birds. Wild birds worldwide carry the viruses in their intestines, but usually do not get sick from them. However, this disease is highly contagious among birds and can make some domesticated birds, including chickens, ducks, and turkeys, very sick and even kill them. To date, avian flu transmission to humans has rarely occurred.
Symptoms of Avian Flu in Birds
Infection with avian flu in domestic poultry causes two main forms of the disease that are distinguished by low and high extremes of virulence. The "low pathogenic" form may go undetected and usually causes only mild avian
flu symptoms, which include ruffled feathers and a drop in egg production. The highly pathogenic form of avian flu spreads more rapidly through flocks of poultry. This form may cause disease that affects multiple internal organs and has a mortality rate that can reach 90 to 100 percent, often within 48 hours.
Avian Flu Symptoms in Humans
Symptoms of avian flu in humans can include typical
influenza-like symptoms, such as:
- Fever
- Cough
- Sore throat
- Muscle aches.
Less severe symptoms can also include eye infections (conjunctivitis).
More serious avian flu symptoms include:
- Pneumonia
- Acute respiratory distress
- Viral pneumonia
- Other severe and life-threatening complications.
