Risk assessment for Toxoplasma gondii in the Danish pig industry

Abstract

The parasite Toxoplasma gondii IS capable of infecting most mammals 1ncluding man. In humans, toxoplasmosis 1s usually asymptomatic but may have serious consequences for pregnant women or immuno-comprom1sed patients. Contact with infected cats and cat litter, contaminated soil and Infected meat are risk factors for toxoplasmosis. Although the prevalence of Toxoplasma in pig production has declined significantly dunng the past 30 years , it has recently been suggested that a large part of human cases of toxoplasmosis may be ascribed to meat, mcluding pork and pork products. Moreover, perinatal screening of pregnant women and infants for Toxoplasma has proven to be of limited value. This has ra1sed the question of how to survey for Toxoplasma • in humans or meat? Therefore, the role of meat, including pigs and pork, as a risk factor for human toxoplasmosis was assessed by the Danish Meat Association. The release assessment showed that outdoor-reared p1gs as well as sows and boars were at higher risk of infection with Toxoplasma. With respect to exposure, consumption of mildly cured pork products and inadequately heat-treated pork were associated with increased nsk. Knowledge on elimination or surv1val of Toxoplasma in cured pork products IS sparse, wh1ch IS unsatisfactory g1ven current trends toward lower salt content and lower cooking temperatures. It was concluded that, aside from consumption of raw pork, wh1ch IS rare in Denmark and not recommended for other reasons, certain m1ldly cured ready-to-eat pork products, that have not been heat-treated, may const1tute a nsk for toxoplasmosis, if not frozen prior to manufacturing. Information on the effects of cunng on surv1val of Toxoplasma in meat is sparse and therefore deserves further research. However, most of the pork used for manufacturing m Denmark onginates from p1gs ra1sed mdoors and for log1st1c reasons it is frozen prior to processmg , thereby reducing the risk for human toxoplasmosis. Ses 10n 3• V•rusos. parasites, other pathogens Safepork 2007-Verona (Italy) 195