May 2009
Influenza A(H1N1) – Biosecurity and Surveillance
The importance of biosecurity and surveillance for influenza on pig farms has been highlighted by the confirmation of a findingby the Canadian Food Inspection Agency, of H1N1 flu virus in a swine herd in Alberta. The pigs were probably infected by a farm worker who had recently returned from Mexico and had been exhibiting flu-like symptoms. The farm has 220 sows and their piglets in two barns and 1,800 growers in four barns. Canada has reported to OIE the possible transmission of the novel A/H1N1 influenza virus from humans to pigs. Clinical signs (respiratory) were observed in the grower population. Mortality had slightly increased in the last few days in weanlings but at the point of reporting it was not certain how much o that increase was attributable to influenza A(H1N1) virus infection.
OIE report: www.oie.int/wahis/public.php?page=single_report&pop=1&reportid=8065
Biosecurity
The advice to pig farmers in the UK is that they should take sensible precautions to protect their pigs from influenza.
- People with flu–like symptoms or who are living with anyone who has flu–like symptoms should not be allowed to come in contact with pigs if it can be avoided.
- People with flu–like symptoms should be encouraged to contact their GP by telephone or seek advice from NHS Direct.
- Any potential visitors should be asked about whether they or any family member have had flu–like symptoms in the previous 7 days.
- It may also be sensible not to allow anyone who has been in Mexico in the previous 7 days to come in contact with pigs.
- All incoming stock should be isolated and quarantined to prevent pig to pig transmission of Swine Influenza viruses.
- Spread on contaminated surfaces, clothing and equipment is a very real risk with influenza and thorough cleansing and disinfecting of all equipment that is shaed between units and ensuring that people take sensible precautions (i.e. showering–in, appropriate changing of clothes etc) is very important.
As the situation will continue to evolve rapidly advice should be kept under review.
Surveillance
The Veterinary Laboratories Agency (VLA) has run a national swine influenza surveillance programme since 1991, funded by Defra and the Scottish Government. This provides free of charge laboratory testing for the detection of swine influenza viruses from clinical samples from affected pigs submitted by veerinary surgeons to VLA Regional Laboratories and Scottish Agricultural College (SAC) Veterinary Services, via the SAC Disease Surveillance Centres. Information Swine Flu Surveillance for Farmers and Vets in Great Britain can be downloaded from the VLA website (www.defra.gov.uk/vla/diseases/dis_si.htm).
Farmers should get in touch with their vet if they see clinical signs that might be suggestive of swine flu. Vets can contact their regional veterinary laboratory for further advice on sampling, if required.
Clinical signs
Clinical signs of influenza in pigs may include:
- sudden onset of high fever
- coughing (“barking”); sneezing
- discharge from the nose or eyes
- breathing difficulties
- eye redness or inflammation
- depression, going off feed
- fevers in infected pigs are common
- reduced fertility or elevated abortion rates among sows.
Food safety
The World Health Organization (WHO)is coordinating the global response to human cases of influenza A(H1N1) and monitoring the corresponding threat of an influenza pandemic. From 30 April 2009 WHO will refer to the new influenza virus as influenza A(H1N1). A Joint FAO/WHO/OIE Statement on influenza A(H1N1) and the safety of pork was reissued on May 7, 2009. The statement makes it clear that Influenza viruses are not known to be transmissible to people through eating processed pork r other food products derived from pigs. In the UK the current system of ante–mortem inspection does not allow sick pigs to be slaughtered for human consumption. Processors may levy disposal charges for carcases condemned as unfit for human consumption.
WHO – http://www.who.int/csr/disease/swineflu/en/index.html
OIE – http://www.oie.int/eng/en_index.htm
FAO – http://www.fao.org/ag/againfo/programmes/en/empres/AH1N1/Background.html
Further information
The situation continues to evolve rapidly and there are links to further information below:
