Journal of Food Protection
Toxoplasma gondii , hepatitis E virus (HEV) and Salmonella are zoonotic foodborne pathogens that may be transmitted to humans through the consumption of raw or undercooked pork. The aim of this study was to determine the seroprevalence of anti- Toxoplasma gondii , anti-HEV and anti- Salmonella antibodies from healthy pigs at slaughter in Switzerland. In the period of August to September 2020 diaphragm muscle of Swiss fattening pigs was collected in three Swiss abattoirs from a total of 188 farms. Two randomly chosen pig carcasses per farm were selected. On the basis of the slaughter data, the production system and the canton of origin were noted, comparing indoor (n=120) and free-range farming (n=68), and regional allocation. The meat juice of these samples was analyzed for pathogen-specific antibodies using commercial enzyme-linked immunosorbent assay (ELISA) kits. The seroprevalences were 1.3% for T. gondii , 71.8% for the HEV and 5.3% for Salmonella , respectively. Comparing the origins, the results of many cantons weren’t meaningful due to the low number of samples. No regional accumulations were found for T. gondii and the HEV. The results showed that 2.1% of the farms had least one T. gondii seropositive animal, 80.3% had at least one HEV seropositive animal, and 8.5% had at least one Salmonella seropositive animal, respectively. The seropositivity of T. gondi i was higher in free-range pigs than in indoor pigs, whereas anti- Salmonella antibodies were more common in pigs from indoor farming than in outdoor pigs. The seroprevalence of anti HEV-Abs was similar in free-range and indoor farming pigs. Compared to studies from 2012 the seroprevalence of T. gondii has decreased whereas the seroprevalence of the HEV has increased and is highly prevalent among fattening pigs in Switzerland. The low seroprevalence of Salmonella has remained stable in recent years.
