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EXOTIC NEWCASTLE DISEASE
Veterinary Services
January 2003
Exotic Newcastle disease (END) is a
contagious and fatal viral disease affecting all species of birds.
Previously known as velogenic viscerotropic Newcastle disease (VVND),
END is probably one of the most infectious diseases of poultry in
the world. END is so virulent that many birds die without showing
any clinical signs. A death rate of almost 100 percent can occur in
unvaccinated poultry flocks. Exotic Newcastle can infect and cause
death even in vaccinated poultry.
Clinical Signs
END affects the respiratory, nervous,
and
digestive systems. The incubation period for the
disease ranges from 2 to 15 days. An infected bird may exhibit the
following signs:
- Respiratory: sneezing, gasping for
air, nasal discharge, coughing;
- Digestive: greenish, watery
diarrhea;
- Nervous: depression, muscular
tremors, drooping wings, twisting of head and neck, circling,
complete paralysis;
- Partial to complete drop in egg
production;
- Production of thin-shelled eggs;
- Swelling of the tissues around the
eyes and in the neck;
- Sudden death;
- Increased death loss in a flock.
How END Spreads
END is spread primarily
through direct contact between healthy birds and the bodily
discharges of infected birds. The disease is transmitted through
infected birds' droppings and secretions from the nose, mouth, and
eyes. END spreads rapidly among birds kept in confinement, such as
commercially raised chickens.
High concentrations of the END virus are in birds' bodily
discharges. Therefore, the disease can be spread easily by
mechanical means. Virus-bearing material can be picked up on shoes
and clothing and carried from an infected flock to a healthy one.
The disease is often spread by vaccination and debeaking crews,
manure haulers, rendering truck drivers, feed delivery personnel,
poultry buyers, egg service
people, and poultry farm owners and employees.
The END virus can survive for several
weeks in a warm and humid environment on birds' feathers, manure,
and other materials. It can survive indefinitely in frozen material.
However, the virus is destroyed rapidly by dehydration and by the
ultraviolet rays in sunlight.
Smuggled pet birds, especially Amazon
parrots from Latin America, pose a great risk of introducing exotic
Newcastle into U.S. poultry flocks. Amazon parrots that are carriers
of thedisease but do not show symptoms are capable of shedding END
virus for more than 400 days.
How Poultry Producers Can
Help Control and Prevent END
The only way to
eradicate END from commercial poultry is by rapidly destroying all
infected flocks and imposing strict quarantine and in-depth
surveillance programs. Poultry producers should strengthen
biosecurity practices to prevent the introduction of the disease to
their flocks. Biosecurity is also important to protect backyard and
hobby flocks. The following are tips on proper biosecurity
practices:
- Permit only essential workers and
vehicles on the premises.
- Provide clean clothing and
disinfection facilities for employees.
- Clean and disinfect vehicles
(including tires and undercarriages) entering and leaving the
premises.
- Avoid visiting other poultry
operations.
- Maintain an "all-in, all-out"
philosophy of flock management with a single age flock.
- Control the movement of all
poultry and poultry products from farm to farm.
- Do not "skim" mature birds from
a flock for sale to a live-poultry market.
- Clean and disinfect poultry
houses between each lot of birds.
- Do not keep pet birds on the farm.
Do not hire employees who own pet birds.
- Exclude vaccination crews,
catching crews, and other service personnel who may have been in
contact with other poultry operations within 24 hours.
- Protect flocks from wild birds
that may try to nest in poultry houses or feed with domesticated
birds.
- Control movements associated with
the disposal and handling of bird carcasses, litter, and manure.
- Take diseased birds to a
diagnostic laboratory for examination.
How Pet Bird and Backyard
Poultry Enthusiasts Can Help Control and Prevent END
END is also a threat to
the caged-bird industry and poultry hobbyists. Birds illegally
smuggled into the United States are not quarantined and tested by
APHIS and therefore may carry the END virus. Owners of pet birds
should:
-
Request certification from
suppliers that birds are legally imported or are of U.S. stock,
are healthy prior to shipment, and will be transported in new or
thoroughly disinfected containers.
-
Maintain records of all sales and
shipments of flocks.
-
Isolate all newly purchased birds
for at least 30 days. Restrict movement of personnel between new
and old birds.
Amazon parrots are difficult to raise
domestically. Anyone who is offering to sell a large number of young
parrots should be suspected of smuggling or purchasing smuggled
birds.
U.S. Department of
Agriculture's (USDA) Role
To prevent END from
being introduced into U.S. poultry flocks, USDA's Animal and Plant
Health Inspection Service (APHIS) requires that all imported birds
(poultry, pet birds, birds exhibited at zoos, and ratites) be tested
and quarantined for diseases before
entering the country.
In addition to international import
restrictions, APHIS has increased surveillance efforts to detect END
if it is accidentally introduced into the United States. APHIS and
State veterinarians trained to diagnose foreign animal diseases
regularly conduct field investigations of suspicious disease
conditions. This surveillance is enhanced by efforts from university
personnel, State animal health officials, USDA-accredited veterinarians,
& industry representatives.
If END were detected in domestic
poultry or pet birds, APHIS would work quickly with its State and
industry counterparts to implement aggressive measures, including
quarantine, control, and cleanup, to prevent opportunities for the
disease to spread.
Reporting Suspicious Cases
Poultry or pet bird
owners or veterinarians who suspect a bird may have END should
immediately contact State or Federal animal health authorities.
Additional Information
For more information,
contact:
USDA, APHIS, Veterinary Services
Emergency Programs
4700 River Road, Unit 41
Riverdale, MD 20737-1231
Telephone (301) 734-8073
Fax (301) 734-7817
The U.S. Department of Agriculture
(USDA) prohibits discrimination in all its programs and activities
on the basis of race, color, national origin, sex, religion, age,
disability, political beliefs, sexual orientation, or marital or
family status. (Not all prohibited bases apply to all programs.)
Persons with disabilities who require alternative means for
communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202)
720–2600 (voice and TDD).
To file a complaint of
discrimination, write USDA, Director, Office of Civil Rights, Room
326–W, Whitten Building, 1400 Independence Avenue, SW, Washington,
DC 20250–9410 or call (202) 720–5964 (voice and TDD). USDA is an
equal opportunity provider and employer.
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