September 14, 2010

UK study shows higher costs of swine flu

Rates of swine flu in pig herds are much higher than previously thought, according to findings from the Royal Vet College (RVC) and COSI Consortium.

Findings showed that out of 20 pigs on each of the 146 farrow-to-finish farms involved in the study, at least one pig tested positive on 59% of the farms. Researchers also discovered most common strain of swine flu in England, AH1N1, was similar to bird flu.

This prevalence of swine flu was much higher than expected, explained RVC's Barbara Weiland. "This highlights the importance of sub clinical infection, and the fact that swine flu virus is a significant production disease that has been underestimated in the past," Weiland said.

Those farms that tested positive for the swine flu virus were also more likely to be infected with other pig pathogens, and had poor respiratory scores in slaughterhouse and monitoring programmes. While the infection may not appear to have much effect on the herd, it does, said Merial vet advisor Ricardo Neto.

Neto noted that the disease has significant economic effects and in some cases can be quite disastrous. In sows, it can affect return to oestrus, cause abortion, increase the number of still born piglets and decrease lactation. Therefore, there is a strong economic case for considering preventative treatment.