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DIAGNOSES:

Clinical Diagnosis:
• Severe depression, inappetence
• Drastic decline in egg production
• Facial edema with swollen and cyanotic combs and wattles
• Petechial hemorrhages on internal membrane surface.
• Sudden deaths (mortality can reach 100%)
• Virus isolation needed for definitive diagnosis

Lesions
Chickens
• Lesions may be absent in cases of sudden death
• Severe congestion of the musculature
• Dehydration
• Substaneous edema of the head and neck area
• Severe congestion of conjunctiva, sometimes with petechia
• Excessive mucous exudates in the lumen of the trachea, or severe hemorrhagic tracheitis
• Petechia on the inside of the sternum, on the serosa and abdominal fat, serosal surfaces and in the body cavity
• Severe kidney congestion, sometimes with urate deposits in the tubules
• Hemorrhages and degeneration of the ovary
• Hemorrhages on the mucosal surface of the proventriculus, particularly at the juncture with gizzard
• Hemorrhages and erosions of the gizzard lining
• Hemorrhagic foci on the lymphoid tissues in the intestinal mucosa

The lesion in turkeys are similar to those in chickens, but may not be as marked. Ducks infected with HPAI and excreting the virus, may not show any clinical signs or lesions.

Differential diagnosis
• Acute fowl cholera
• Velogenic Newcastle disease
• Infectious laryngotracheitis
• Infectious Bronchitis

LABORATORY DIAGNOSIS
Procedures
Identification of the agent
• Inoculation of 9-11 day old embryonated chicken eggs followed by:
a. demonstration of hemagglutination
b. immunodiffusion test to confirm the presence of influenza A virus
c. subtype determination with monospecific antisera
d. strain virulence evaluation intravenous pathogenicity index (IVPI) in 4 – 8 week-old chickens

Serological tests
• Hemagglutination and hemagglutination inhibition tests
• Agar gel immunodiffusion

Samples
Identification of the agent
• Tracheal and cloacal swabs (or feces) from live birds or from pools of organs and feces from dead birds

Serological tests
• Clotted blood samples or serum
TREATMENT

No specific treatment

Sanitary prophylaxis
a. Avoidance of contact between poultry and wild birds, particularly waterfowl
b. Avoidance of the introduction of birds of
unknown health status into a flock
c. Control of human traffic
d. Proper cleaning and disinfection procedures
e. Practice an “all in-all out” system in the poultry farm

In outbreaks
a. Slaughtering of all birds
b. Disposal of carcasses and all poultry products
c. Cleaning and disinfection
d. Allow at least 21 days before restocking

Medical prophylaxis
In the past it has been considered counterproductive to vaccinate against HPAI as some vaccinated individuals may nonetheless become infected and shed virulent virus.
However, in the recent outbreaks in Pakistan and Mexico, inactivated vaccines have been employed to combat rapidly spreading disease.

Reference: Office of International des Epizooties

For inquiries call Avian Flu Task Force
Bureau of Animal Industry
Visayas Avenue, Diliman, Quezon City
Tel. Nos. (632) 928 – 2743,
(632) 928 –2836, (632) 927 – 0971, (632) 925 – 9227

Source:www.openacademy.ph