Summary

Report type Follow-up report No. 1
Start date 21/04/2009
Date of first confirmation of the event 01/05/2009
Report date 11/06/2009
Date submitted to OIE 11/06/2009
Reason for notification Emerging disease
Morbidity 25 %
Mortality 0 %
Zoonotic impact Possible transmission of the novel A/H1N1 influenza virus from humans to pigs.
Causal agent Novel A/H1N1 2009 influenza virus
Serotype Other
This event pertains to the whole country
Related reports Immediate notification (02/05/2009)
Follow-up report No. 1 (11/06/2009)

Outbreaks There are no new outbreaks in this report

EpidemiologySource of the outbreak(s) or origin of infection Possible transmission from humans to pigs.

Epidemiological comments On 5 May 2009, CFIA reported that the full sequence of the virus detected in swine on an Alberta farm confirmed that the virus found in the pigs was the same as the novel H1N1 influenza A virus causing illness in humans around the world.
The CFIA developed a strategy/approach/plan to resolve the animal health issues associated with this farm, in line with the public health concerns. Public health and animal health authorities, nationally and internationally, were engaged in discussion. All groups and organizations supported the “controlled marketing with no cull” approach which the CFIA advocated.
Clinical signs of respiratory disease observed in the herd at the beginning of the outbreak have resolved and hogs in all affected subpopulations have since recovered. Crowding conditions in the barn forced a limited cull of approximately 500 mature hogs to alleviate animal welfare concerns and to allow a period of time to do testing in the herd. The hogs were humanely destroyed and transported to a rendering establishment. The rendered material was buried in landfill due to concerns about negative public perception of incorporating it into animal feeds.
PCR tests on samples collected on 14 and 25 May showed evidence of continued virus presence but at a low prevalence. Isolating virus from these samples has not been successful, to date.
Research activities to determine the virulence of the novel H1N1 virus for animals and the associated risk have been undertaken. The preliminary results indicate that the novel virus produces clinical signs similar to the traditional influenza A viruses in swine.
The initial risk management decisions in this herd were precautionary due to the lack of information to determine the risk to the swine and human populations of North America. It was first suggested that a virus negative test was needed to release movement restrictions. However, although additional information provided insight to the lower risk this virus would pose to the human and animal community, it became difficult to modify the initial precautionary approach and identify alternate criteria for the release of the quarantine. In spite of clinical recovery and negative status of market weight animals, market forces resulted in there being no slaughter facility willing to receive the animals.
Due to an impending and further overcrowding situation in the barns and an inability to market the animals following lifting of restrictions, the owner petitioned the Alberta provincial government for the destruction of the herd for economic reasons, to allow him to exit the situation and resume operation with a replacement herd. The culling of the herd was NOT an ordered destruction as the result of animal or human disease considerations.
The quarantine will be lifted when appropriate cleaning and disinfection measures have been completed on the infected premises. The trace out/ trace in investigation is complete. No additional farms at-risk were identified.


Control measuresMeasures applied Quarantine
No vaccination
No treatment of affected animals

Measures to be applied Disinfection of infected premises/establishment(s)



Future ReportingThe event is continuing. Weekly follow-up reports will be submitted.