Seroprevalence of Toxoplasma gondii infection in sows and finishers from conventional and organic herds in Denmark: implications for potential future serological surveillance

Abstract Pigs are one of several host species for Toxoplasma gondii parasites, and consumption of infected pork may lead to toxoplasmosis in humans. We estimated seroprevalence in sows and finishers from conventional and organic herds in Denmark and discussed the strategies for reducing the risk from pork. We collected 447 blood samples from 59 herds, and additional meat-juice samples from 212 of the same pigs. Using a T. gondii IgG commercial ELISA test, we found 2% (CI95% = 0.4% – 5%) apparent seroprevalence of T. gondii in conventional finishers, 11% (CI95% = 6% – 17%) in organic finishers, 19% (CI95% = 11% – 30%) in conventional sows and 60% (CI95% = 47% – 72%) in organic sows. The odds of an animal testing positive for T. gondii was 16 times higher (CI95% = 4.6 – 74.3) in organic compared to conventional herds. The odds were 22 times higher (CI95% = 6.5 – 88.3) if the animal was a sow compared to a finisher. Meat-juice ELISA values were significantly correlated with plasma results (P