They have confirmed that one H5N1 strain was isolated in 2002 from materials collected from pigs in the Fujian province in 2001. Subsequently, 1936 samples were collected in 2003 from pigs in 14 provinces including Fujian and again one H5N1 strain was isolated from that province. These two isolates have been subjected to detailed analysis and have been shown to be highly homologous to the duck-derived H5N1virus isolated recently in birds in China. According to the Chinese authorities, no variation in the virus has been observed. More recently, as part of their ongoing epidemiological surveillance programme, 1.1 million samples including 4447 from pigs have been collected and analysed between April and August 2004 from 10 provinces including Fujian, and no infection from H5N1 has been detected in pigs.

The above findings do not at this stage indicate any major evolution regarding H5N1 infection in pigs. However, the OIE wishes to insist on the necessity for Member Countries affected by avian influenza to increase their epidemiological surveillance to better understand the implications of the existence of H5N1 virus in pigs.

Source: Office International des Epizooties - 1st September 2004