Distribution of Toxoplasma gondii and Neospora caninum under aspects of meat hygiene

Toxoplasma gondii and Neospora caninum are phenotypically and phylogenetica lly closely related cyst-forming coccidia, both of which may cause abortion in livestock animals. T. gondii exhibits also zoonotic potential by causin g diaplacental infections in the human fetus and harmful infections in immu nosuppressed individuals. Humans get infected either by consuming inappropr iately prepared cyst-containing meat or by ingesting oocysts originating fr om cat feces. Therefore, in order to assess infection risk we need to have knowledge on the prevalence of the parasite in consumable meat and thus sla ughtered animals. So far, no data indicate any zoonotic potential for N. ca ninum. Due to its high economic impact in the bovine production in Switzerl and, we included this parasite in the present study as well. The prevalence of both parasite species were investigated by PCR in muscle and brain samp les of slaughtered bovines, sheep, pigs and horses. Comparatively, a serum sample from each animal was simultaneously tested serologically by a Toxopl asma-P30-ELISA and a Neospora-SA-ELISA. The prevalences determined by the T . gondii-PCR were the followings: adult cows 3%, young bulls 2%, young cows prior to gravidity 6%, calves 1%, sheep 6%, horses and pigs each 0%. For N . caninum, the PCR-prevalence was 2% for adult cows and 0% for all other an imal groups. Conversely, the seroprevalences were much higher for both para site species and all animal groups, with the exception of the fattening pig s. However, as T. gondii was principally detectable in bovine (cows and cal ves) as well as in sheep meat, the consumption of this meat harbours a pote ntial infection risk for humans. In contrast, the lack of any parasite dete ctability in fattening pig and horse meat allows to consider this infection source as neglectable when compared to bovine and ovine meat.