Avian Influenza

Severe outbreaks of highly pathogenic avian influenza in birds throughout Asia, Africa, and Europe have resulted in human deaths, raising concern about its potential for adaptation to humans due to the extensive direct contact with infected birds.

Avian Influenza is first of all a poultry disease affecting poultry production and international trade.  The control of Avian Influenza really starts with control in poultry.


Avian Influenza viruses affect various types of birds, producing respiratory disease commonly named "bird flu."

Infection of domestic poultry by avian influenza viruses typically produces syndromes ranging from asymptomatic infection to respiratory disease and drops in egg production to severe, systemic disease with near 100% mortality depending on the pathotype involved.

The lethal disease is caused by the Highly Pathogenic Avian Influenza (HPAI) virus which has been associated only with some strains of H5 and H7 viruses.

Low Pathogenic avian influenza (LPAI)- subtypes of H5 (H5N2), H7 (H7N1, H7N7) and H9 (H9N2) causes minor sickness or no noticeable signs of disease. Some low mortality and mild respiratory disease or drops in egg production can be as well reported.

Avian Influenza

Ischemic lesions on the comb and the wattles

Avian Influenza

Ischemic lesions on the wattles

Avian Influenza

Cyanosis of the shanks.

HPAI signs:

  • Sudden death.
  • Drops in egg production.
  • Depression. Reduced feed consumption.
  • Respiratory signs with coughing and nasal and ocular discharge.
  • Swollen face.
  • Cyanosis of comb/wattles.
  • Diarrhea (often green).
  • Nervous signs such as paralysis.