15 September 2000

By Peter Crichton

The pig industry ended the week on a pessimistic note following the news of two further positive classical swine fever tracings in mid Norfolk and on the Norfolk/Suffolk border.

This confirms vets fears that the virus is a new “super-strain” with a greatly extended incubation period. Earlier types of CSF normally have a five to 15 day incubation period but the new variant could be as long as 30 days.

This has lead MAFF to embark on a further series of testing in the Essex surveillance zone which is due to be lifted today (15 September).

One of the latest outbreaks has been outside the BQP pyramid which has added to fears of further outbreaks among a much wider circle of producers. However, the cause of this infection is believed to be lateral spread from a nursery unit which had been slaughtered out in August.

Vets have warned that infection can be spread among neighbouring pig units by birds and other wildlife as well as by conventional pig and vehicle movements. Bird infestation is common on many outdoor pig units where feed is freely available on a daily basis. The virus can be spread from recently slaughtered infectious farms to healthy ones as bird flocks search for new feed sources.

MAFF have also introduced much more stringent controls over pig movements with the creation of Movement Restriction Areas within 10km of any suspect farms. Previously MAFF had waited for blood test results before movement restrictions were applied.