PRRS Outbreak Affects Pigs in Chile
CHILE - The Chilean veterinary authorities have reported three outbreaks of porcine reproductive and respiratory syndrome (PRRS), also known as blue ear disease, at a pig farm in Metro de Santiago.
4 November 2013
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The World Organisation for Animal Health (OIE) received follow-up report no. 2 on 30 October 2013. According to the report, antibody detection ELISA and real-time reverse transcriptase/polymerase chain reaction (RRT-PCR) tests were conducted on 24 October confirming the presence of the PRRS arterivirus.
A total of 75 pigs were found susceptible, out of which three cases were reported. All 75 pigs were slaughtered. No animals were found dead.
According to the OIE, the first outbreak (3 September) concerns a non-industrial fattening farm that buy and sell animals of the porcine species. These animals are fed with waste.
On 3 September, clinical signs of diarrhea and mortality were observed in piglets. This event was not notified to the official Service.
Subsequently, on 25 September, the establishment was sampled within the surveillance programme of exotic diseases for other diseases (not included PRRS) and sera from this sampling were used subsequently, on 25 October, for the diagnosis of PRRS.
The second outbreak, which took place on 23 October, concerns a backyard adjacent to the first outbreak. This farm bought pigs from the farm related to the first outbreak.
The third outbreak also occurred on 23 October and concerns a backyard adjacent to the first outbreak as well. This farm too bought pigs from the farm related to the first outbreak.
While the source of the first outbreak has not been determined, introduction of pigs from the first outbreak has been identified as the source of the two later outbreaks.
According to the OIE, genotyping indicates that the current strain has no relation with the strain eradicated in 2007; therefore, it would be a new strain of the virus. Sequencing of the circulating strain shows a similarity between 95 per cent and 97.7 per cent with strains from Mexico and the United States of America. The strains in the outbreaks occurring in industrial-type farms have a similarity of 99.2 per cent with the strains in the backyard outbreaks.
