Avian Influenza: Protecting Flocks, Protecting People Akrum Hamdy

What is avian influenza? A disease of birds that occurs around the world from time to time Can be mild (low pathogenic) or severe (highly pathogenic) “Asian” strain is called H5N1 highly pathogenic avian influenza (AI) HPAI causes high death rate in flocks

Spread mainly by wild birds Geese and ducks can carry the virus without having symptoms If chickens and turkeys are allowed to commingle with wild geese and ducks, they can get the virus and develop disease Migratory birds can carry the virus long distances Locally, virus can be tracked by humans

Avian and Pandemic Influenza There is a epidemic if you are a chicken in Southeast Asia: H5N1 highly pathogenic avian influenza of specifically Eurasian lineage Over 100 million birds have died or been destroyed Only weakly transmissible to humans through close contact with infected animals No sustained human-to-human transmission

Preventing a Pandemic in Humans If highly pathogenic AI is not allowed to exist in poultry, it will not have the opportunity to mutate to a form in which it can be hazardous to humans Objective is to prevent human pandemic from arising in U.S. U.S. government should assist foreign governments in similar programs overseas

Could Asian AI spread to the US? Most likely route is via mingling of migrating birds in Alaska U.S. has taken 13,000 samples in Alaska with zero H5N1 HPAI and only 313 avian influenza virus (AIV) of any kind Very extensive sampling is being done in remaining 49 states Several detections so far of low-pathogenic, North American H5N1 AIV not related to Asian form

Biologists taking sample in Alaska Samples taken in Alaska in 2006: 13,000 + H5N1 HPAI found: Zero

Preventing HPAI outbreaks in US We have never had highly pathogenic H5N1 AI in North America Industry is working closely with government to detect and eliminate any introduction of the hazardous forms of avian influenza into commercial poultry flocks Surveillance, biosecurity and testing, are all key to preventing outbreaks

Protective sheltered environment Chickens in the U.S. are raised almost entirely in enclosed houses – prevents mingling with migrating birds

Restricted access to farms Sorry, no visitors – prevents accidentally tracking the virus onto the farm

Service vehicles Vehicles that must come on the farm are sanitized

Industry testing program NCC-sponsored testing program requires that every flock of a participating company is tested before going to market. Any flock with H5 or H7 AI – regardless of pathogenicity – will be destroyed on the farm Program is being implemented by companies that produce the vast majority of meat chickens in the U.S.

Laboratory Testing: Avian Influenza Serology – 24 hour test (check for antibodies) Antigen capture – 15 minute test (necropsy and in the field) Polymerase chain reaction (PCR) – 4 hour test (H5 or H7) Virus isolation – 72 hour test (H5 or H7) ***** Positive samples sent to the National Veterinary Services Laboratory (NVSL) – typing, H5 or H7, lineage, and pathogenicity

Control Program for Avian Influenza Response plans – rapid response Tested on previous avian influenza outbreaks – effective Cooperation – state Department of Agriculture, USDA, industry, universities, laboratories, and Health Department Law enforcement, FBI, and emergency management personnel

Avian Influenza Outbreak Call state veterinarian Samples sent to NVSL – overnight Geographic information system – map Department of Agriculture personnel: flock visit – quarantine and collect additional samples Surveillance on surrounding and contact farms In the past it has been the first case – not widespread If several cases or highly pathogenic, USDA personnel assist with control efforts Depopulation – clean-up

Reaction to Outbreak If an outbreak occurs: infected flock would be destroyed on farm immediately and buried on the premises or composted in the growout house Isolation, quarantine and movement controls would be instituted and nearby farms tested Aim is to limit spread of disease and prevent a widespread outbreak

Questions? Akrum Hamdy akrum312@hotmail.com