Seroprevalence of Toxoplasma gondii infection in ruminants in selected districts in Bangladesh

To estimate the seroprevalence of toxoplasmosis and risk factors for seropositivity in sheep, goats and cattle in Dhaka, Mymensingh, Sirajganj and Chittagong districts in Bangladesh, 1104 sera samples (552 sheep, 300 goats and 252 cattle) were randomly selected and tested by an indirect enzyme linked immunosorbent assay (iELISA). The overall seroprevalence was 12.2% (135/1104), and was significantly (P = 0.008) higher in goats (16.0%) than cattle (8.3%). The odds of seropositivity was 2.09 times (95% confidence interval [CI]: 1.23-3.67) higher in goats than cattle. In sheep, herd type, district and pregnancy status were significant risk factors. The odds of seropositivity was 2.1 (95% CI: 1.00-4.84), 7.29 (95% CI: 12.71-423.41) and 10.88 (95% CI: 5.42-23.41 times higher in sheep-only flocks, in Mymensingh district and in pregnant sheep than in mixed flocks, Chittagong district and non-pregnant sheep, respectively. In cattle, breeds and district were significant risk factors. The odds of seropositivity was 5.79 (95% CI: 1.13-24.62) and 4.29 (95% CI: 1.38-16.34) times higher in Holstein Friesian cross cattle and in Mymensingh district than in indigenous cattle and Chittagong district, respectively. This study indicates that exposure of sheep, goats and cattle to oocysts of T. gondii is widespread, suggesting that the consumption of raw and undercooked meat of these animals might be a source of human toxoplasmosis. Risk factor information can be used to design control programs to reduce exposure.