Influenza A and Livestock in Ontario
Update for Veterinarians

As of July 7, 2005 there have been at least 24 confirmed cases of H3N2 influenza A virus on Ontario swine farms. There has also been one case detected in a poultry operation. Cases continue to be detected through laboratory submissions and clinical history. However, the incidence of new cases does not appear to be escalating. Cases are concentrated in southwestern Ontario, although the virus has also been detected in eastern Ontario. In order to better track the spread of this virus in the province, OMAFRA will be covering the diagnostic testing fees on samples submitted to the Animal Health Laboratory from suspected cases of influenza in swine and poultry until at least July 31, 2005.

Veterinarians should continue to stress strict biosecurity with their clients. Influenza viruses are usually transmitted by direct contact between infected and susceptible individuals, or via contaminated clothing and equipment. Based on the epidemiological investigations of affected swine farms in western Canada, and anecdotal evidence from Ontario, there is some concern that airborne spread may be playing a role in some cases. In addition to routine biosecurity measures, veterinarians should help their clients evaluate their premises for the presence of major risk factors, such as proximity to major livestock transportation routes, and determine if additional precautions are warranted.

A bivalent vaccine which contains H1 and H3 antigens is licensed for use in swine. Veterinarians should consult the OMAFRA contact listed below or a member of the Ontario Association of Swine Veterinarians (OASV) for advice on the appropriate use of influenza vaccines for their clients. There is currently no influenza vaccine licensed for use in poultry in Canada. However, the Canadian Food Inspection Agency will be meeting with poultry industry leaders and veterinarians in affected provinces to discuss the selective use of vaccination in poultry.

While this H3N2 strain does not pose a significant threat to human health, a possible case of infection in a farm worker from an infected swine operation is currently being investigated by public health authorities. Clinical infection of humans with livestock and poultry subtypes is known to occur, and those in close contact with infected animals are most at risk. Veterinarians should consider wearing personal protective equipment when dealing with influenza suspect herds or flocks. Specific recommendations from the Ministry of Health and Long Term Care are included in the attached documents being sent to swine and poultry industry associations for distribution to producers and farm workers.

Unless the risk associated with this situation changes, OMAFRA will not be issuing further updates. For more information, contacts and resources are listed below.

Contacts

OMAFRA media contact through Communications Branch (519) 826-3198

OMAFRA technical assistance for veterinarians:

Dr. Tim Blackwell (519) 846-3413 (swine)
Dr. Babak Sanei (519) 824-4120 x 54650 (poultry)

AHL contact for submissions:

Dr. Susy Carman (519) 824-4120 x 54551
Dr. Davor Ojkic (519) 824-4120 x 54524
Dr. Jim Fairles (519) 824-4120 x 54611

General Information on Influenza in Poultry

http://www.poultryindustrycouncil.ca/avian_influenza.html
http://www.oie.int/eng/AVIAN_INFLUENZA/home.htm

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