Transcript AVIAN INFLUENZA

AVIAN INFLUENZA:
Zoonosis
Vicente C. Manalo, Jr., DVM
Maria Fidelis Manalo, MD,
MSc Epidemiology
Avian Influenza
• A Viral disease of Domestic and
Wild Birds characterized by the
full range of responses from
almost no signs of the disease
to very high mortality. The
incubation period is also highly
variable, and ranges from a few
days to a week (3 to 7 days).
Aetiology of Avian Influenza
• Influenzavirus A genus of the
Orthomyxoviridae family.
• They are enveloped, negative
stranded RNA viruses.
• Influenza A viruses can be
divided into 15 Haemagglutinin
(H) antigens. 9 Neuraminidase
(N) antigens.
• Extreme antigenic variability
brought about by genetic
reassortment in host cells.
Influenza Viruses
• 2 Pathotypes:
 HPAI
 LPAI
Ecology of Avian
Influenza Viruses
• The greatest variety of Avian
Influenza viruses has been isolated
from wild birds, particularly from
waterfowls.
• Serve as reservoirs and gene pools
• These birds perpetuate only viruses
of low pathogenecity
• Natural host of AI viruses to which
the viruses are well adapted.
• Waterfowls are resistant to the
disease induced by HPAI viruses.
Ecology of Avian
Influenza Viruses
• Domestic Poultry does not appear
to be the natural host of these
viruses, therefore the degree of
adaptation to the host is low and
this could possibly explain why
documented virus mutation has
virtually always occurred in
domestic poultry
Highly Pathogenic Avian Influenza
Worldwide Occurrences
Recent News
• Indonesia: Poultry Disease Outbreak
Devastating Regional Sector.
• An article in the Jakarta Post on Dec. 18:
• Many poultry farmers forced out of
business in the face of the current
outbreak of ND. A spokesperson for 1 of
the Sleman and Kulonprogo Regency
district sector said: Out of 25 members of
the neighborhood unit, only 3 still have
chickens. The others’ birds are all dead. He
added that only 25 % of farmers in his area
are still operating. The virus had also
spread to other areas of the regency. Some
estimates suggest that a number of district
have lost up to 80 % of their poultry
South Korea – Latest Developments
• The Government is doing its best to
support the industry but public are not
buying poultry or eggs despite
assurances that this form of AI does not
pose a health hazard.
• First confirmed case of bird flu – Dec.
15, 2003: 49 suspected farms
• 14 cases confirmed positive for AI
• 7 cases are from ducks
• 1 from broiler breeder
• 2 from broilers
• 4 from layers
• 17 cases were negative
• The other 18 farms are being tested
Taiwan – Latest
Developments
• Taipei (Reuters, Jan 5,2004)
Taiwan reported its first case
of a highly contagious bird flu
Wednesday (Dec. 31,2003), but
said six ducks smuggled from
mainland China that had tested
positive (H5N1) had been
destroyed.
Avian Influenza
Differential Diagnosis
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Infectious Bronchitis
TRT/APV
Newcastle Disease
Respiratory viruses – Mixed
infections
Avian Influenza
Diagnosis
1. Clinical Signs
2. Virus Isolation and
Characterisation
3. Serology
4. PCR
5. Histopathology and
Immunochemistry
3 Categories of Transmission
• Intercontinental
• Transport of live poultry, frozen poultry meat and
untreated hatching eggs over long distances. Trade of
poultry by-products unheated and egg products and
possibly frozen poultry semen. Least importance are
free living migrating birds
• International
• Trade of commercial poultry including live birds,
vehicles, crates, containers. Also, international
exhibitions, shows, bird markets and similar events.
Least important are birds which displays seasonal
migration pattern.
• Local
• Farm personnel, technical crew (debeaker,
vaccinators, catchers, etc.). Also, contaminated
poultry manure and waste stuff as well as airborne
particle and dust. Significant are live birds in close
vicinity to poultry houses
BIOSECURITY
• DEFINITION : all procedures
used to prevent the introduction
of disease
• OBJECTIVES :
- prevent the entry of disease
- control the spread of
disease
BIOSECURITY IS EVERYONE’S
RESPONSIBILITY!
BENEFITS OF BIOSECURITY
• HELPS KEEP OUT diseases
• REDUCES THE RISK of zoonotic
diseases
• LIMITS THE SPREAD of diseases
• HELPS PROTECT the public health
• IMPROVES the overall flock health
• CUTS COSTS of disease treatment
• REDUCES LOSSES and improves
profitability
BETTER BIOSECURITY PROVIDES :
Peace of mind, a healthier flock and
a more viable business!
HOW DISEASES SPREAD
• MOVEMENT of people, animals,
equipment, vehicles
• CONTACT with neighboring
flock
• CONTACT with insects, rodents,
stray animals and pets
• CONTAMINATED water & feeds
• INADEQUATE cleaning and
disinfection
BIOSECURITY INFORMATION
• STRICTLY limit and control access
to the farm – fencing w/ a controlled
entry point
• KEEP an all-in, all-out flock
management
• PROVIDE a security or
decontamination area
• REQUIRE all persons entering the
farm to sign a visitor’s logbook;
vehicle plate numbers must also be
recorded
BIOSECURITY INFORMATION
• CLEAN & DIRTY areas should be
well-defined
• THOROUGHLY clean and disinfect
all equipment & vehicles entering
AND leaving the farm
• BETTER NOT to borrow equipment
or vehicles from other farms
• DON’T USE same vehicles for
transporting birds, feeds,
equipment or waste products
BIOSECURITY INFORMATION
• CLEAN, PROTECTIVE clothing and
footwear must be worn in the farm
• HAVE a designated cleaning &
disinfecting area
• WHEN DISINFECTING, remove all
dirt & solid matter first – Dirt &
manure cannot be disinfected!
• KEEP the farm surroundings clean
& tidy
• FOOTBATH must be provided in
every poultry house; footbath
should be kept clean
BIOSECURITY INFORMATION
• KEEP WILD BIRDS off the poultry
houses – bird-proofing
• KEEP other animals, pets or other
livestock out of the farm
• PEST & RODENT control program
• PROPER DISPOSAL of damaged
eggs, dead birds, litter or manure
• REGULARLY clean & disinfect all
equipment & vehicles before and
after use
BIOSECURITY INFORMATION
• AFTER EVERY CYCLE,
thoroughly clean & disinfect all
houses & equipment
• ONCE CLEANED, a farm should
be closed & left idle; the longer
the down time, the better the
results.
IMPLEMENTING A STABLE
BIOSECURITY PROGRAM IS
INDEED AN EFFORT WORTH
MAKING!
MINIMUM BIOSECURITY
STANDARDS
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No Visitors
A sign-in log
Clean clothing and sanitized footwear
Properly maintained foot pans with
disinfectant solution
Rodent and insect control
No other animals, esp. wild birds
Vaccination
All in, all out
Sanitize hands
IMPORTANT
REMINDERS
• MAKE a flock health plan that
includes basic biosecurity measures
• ENSURE that all records are
accurate & up-to-date
• ALL poultry personnel should be
trained
• LOOK OUT for signs of disease –
early detection is key!
• REPORT immediately if disease is
suspected
BE VIGILANT!
Reminders
• Effective Bird Proofing
• Working Pest Control Program
• For Rodents and Fly
• No other animals especially
waterfowl
• Sign – in Log Book
• Power Sprayer at the farm gate
• Separate foot wear/Foot Dip
• Sanitation/disinfection
Prevention
• Surveillance / Monitoring
• Vaccination
• Biosecurity
Control
• Biosecurity
• Quarantine
• Intensify disinfecting measures
• Monitoring/Surveillance
• Stamping Out / Depopulation
• DIVA Vaccination - only for LPAI
and not for HPAI because it
might prolong the shedding of
the virus
• Proper Disposal
• Avian Influenza Pictures and
Video Clips were taken from
A Color Atlas and Text on Avian
Influenza and CD ROM Avian
Influenza
• Ilaria Capua and Franco Mutinelli
• Published by Papi Editore