A high prevalence of Toxoplasma in Australian chickens

A small survey was undertaken of commercially reared free-range chickens in Western Australia using serology and molecular detection. Eighteen out of 20 serum samples showed antibody responses with titers of 1:64 in 5 chickens and ≥ 1:128 in 13 chickens. DNA extracted from 22 out of 50 tissue samples, 10 brains and 12 spleens, were positive by nested PCR, and sequencing at the B1 locus on DNA from 3 brain and 3 spleen samples confirmed that 2 isolates were Toxoplasma gondii, Type I, and 4 Type II/III. The high prevalence of Toxoplasma infection found in commercial, free-range chickens raises public health issues with respect to both exposure in the workplace, during carcass processing, and subsequent transmission during food handling and/or consumption as food. The results of this study emphasize the need for more data on the incidence of Toxoplasma infection in domestic animals and humans in Australia.