The veterinary authority sent Follow Up Report No. 1 dated 10 March to the World Organisation for Animal Health (OIE).

On 16 February, three out of six samples collected in annual survey at the slaughterhouse tested serological-positive. Twenty samples taken later from the farm of 582 fattening pigs at Le Cerneux-Péquignot in canton Neuchatel were all negative. All pigs have been slaughtered.

The outbreak is described as 'resolved'.

The report adds that Switzerland conducts annual surveys to demonstrate freedom from PRRS. Sampling takes place at the slaughterhouse.

Serological samples from fattening pigs were positive for antibodies against PRRS virus, American type, on 28 January 2014.

Tracing back revealed several breeding farms as a possible source. All but one of the breeding farms has since been tested with negative results for antibodies and virus.

The one farm had also seropositive pigs in samples collected on 28 February. The affected farm is an almost closed farm with breeding and fattening unit.

In epidemiological investigation, it became clear that samples taken on 27 January 2014 for a research project were still available for testing. These samples were positive in PCR and virus of American type (type 2) was isolated. The virus showed 100 per cent similarity with field and vaccine virus type 2 in sequencing of ORF7. There is no connection with the virus found in the event in 2012, which was caused by PRRS virus type 1 (European type).