Experimentally assessed public health risks associated with pigs from farms experiencing anthrax

Following an outbreak of anthrax in an intensive pig rearing unit in north Wales in 1989 a study was initiated by the Ministry of Agriculture, Fisheries and Food to assess public health risks during such an outbreak. Of 50 pigs infected by the addition of Bacillus anthracis spores to their feed, two died of anthrax six and eight days later. The remainder were observed for 21 days and exhibited only mild and transient clinical signs of disease. As judged by the results of bacteriological culture of appropriate tissues from the survivors, it was concluded that meat from healthy pigs killed 21 days after the latest case during an outbreak would not pose a public health risk.