Saturday, August 14, 2010

Pigs in Indonesia have asymptomatic H5N1 infections

An international team of researchers reports finding asymptomatic H5N1 avian influenza infections in pigs in Indonesia in 2005, 2006, and 2007, suggesting that the animals offer the virus an opportunity to adapt to mammals. The team sampled pigs in several areas of Indonesia during three rainy seasons: January and February 2005, October 2006 to February 2007, and November 2008 to April 2009, according to their early-release report in Emerging Infectious Diseases (EID). They found H5N1 viruses in 52 of 702 samples (7.4%). All the positive samples were collected in the first two seasons and came from areas where poultry outbreaks of H5N1 had occurred. None of the pigs showed signs of flu-like illness at the time of sample collection.

A phylogenetic analysis showed that the viruses had been introduced into pigs in Indonesia on at least three occasions. The researchers also found one isolate that had the ability to recognize human-type virus receptors. "Our data suggest that pigs are at risk for infection during outbreaks of influenza virus A(H5N1) and can serve as intermediate hosts in which the virus can adapt to mammals," they conclude.
Early-release EID report

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