Viral Diseases - NEWCASTLE DISEASE

(Pseudo Fowl Pest) 

AGENT:

Newcastle disease virus, family Paramyxoviridae.

RESERVOIR AND INCIDENCE:

The natural reservoir is wild and domesticated birds. 

TRANSMISSION:

Transmission is by inhalation of infectious aerosols. Intensive conditions favor spread by contact, on inanimate objects and airborne between poultry houses. Human infections occur mainly amongst laboratory workers and those who work with infected chickens or who give live vaccine, especially by aerosol. 

DISEASE IN ANIMALS:

In poultry, respiratory and nervous signs occur, including gasping and coughing; also drooping of wings, twisting of the head and neck; inappetence and paralysis. Egg production ceases. Petechial hemorrhages are characteristic, especially in the preventricular mucosa. Necrosis of the intestinal mucosa give a "bran" like appearance. Congestion and mucoid exudate appears in the lungs and bronchi. 

DISEASE IN HUMANS:

Usually symptoms are confined to painful conjunctivitis lasting a few days, but fever and influenza-like symptoms for up to 3 weeks may follow. 

DIAGNOSIS:

Virus isolation or ELISA. 

TREATMENT:

Symptomatic. 

PREVENTION/CONTROL:

Hygienic precautions are needed when handling infected birds. Avoid inoculation injuries and ensure laboratory safety. Maintain strict hygiene in poultry sheds and quarantine of imported live birds, prohibit importation from infected countries, sterilization of, or prohibition on, waste food fed to poultry. Vaccination of poultry.