Serological survey of Toxoplasma gondii infection in pigs slaughtered in Sweden.

The prevalence of Toxoplasma gondii infection in Swedish pigs was investigated by analysis of 807 meat juice samples collected in 1999 from 10 abattoirs in different parts of the country. When analysed using ELISA, 42 (5.2%) of the samples were found to be positive. The seroprevalence was 3.3% in fattening pigs (n = 695) and 17.3% (n = 110) in adult swine. Alternative interpretations of the results, considering estimates of the true prevalence based on the sensitivity and specificity of the test method, are discussed. It is concluded that the risk of contracting T. gondii infection as a result of eating undercooked pork from Swedish pigs, especially adult animals, is not negligible.