Seroepidemiology of Toxoplasma gondii in small ruminants in Northwest Ethiopia.

Abstract

This cross-sectional study with a cluster random sampling method was undertaken from November 2018 to May 2019 to estimate the prevalence and assess the potential risk factors of T. gondii seropositivity, and to assess the association of the T. gondii seropositivity with reproductive losses in small ruminants in Northwest Ethiopia. A total of 576 blood samples from 135 small ruminant flocks were collected and assayed for T. gondii IgG antibodies using the Toxo-latex slide agglutination test. A questionnaire survey was also conducted to gather information on the potential risk factors of T. gondii seropositivity and on the status of reproductive losses in the small ruminant flocks. The study demonstrated a high flock and animal level T. gondii seroprevalence of 96.3% (95% CI: 91% - 98%) and 70.48% (95% CI: 68% - 79%), respectively. Mixed effect logistic regression analysis of the potential risk factors showed that the odds of seropositive for T. gondii was significantly higher in sheep (OR=1.7, 95%CI: 1.19-2.46) than in goats, in adult (OR=1.6, 95%, CI: 1.11-2.31) than in young, in the presence of cats (OR=2, 95%CI:1.32-3.04) than in the absence of cats, in the lack of knowledge on the role of cats as a pathogen source than knowing it (OR=1.82, 95% CI:1.21-2.77). The study also showed that the likelihoods of experiencing the abortion, neonatal death and weak birth in the previous one year in T. gondii seropositive flocks were 20.76 (95% CI: 2.2-195.1, p<0.001), 8.90 (95% CI: 1.99-83.0, p=0.021) and 9.33 (95% CI: 1.1-86.2, p=0.019) times more than the seronegative flocks, respectively. In conclusion, this study revealed high flock and animal level seroprevalence of T. gondii in the small ruminant population in northwest Ethiopia, suggesting that lamb and goat might be a source of this pathogen for human infection if their infected meat is consumed undercooked or uncooked. Besides, the observed association of T. gondii seropositivity with reproductive losses may suggest the economic importance of the pathogen for the small ruminant producers. Therefore, it warrants control attention to reduce its economic and public health burden in the study areas. Further works on the economic impacts, bioassay, isolation, and genetic characterization of the pathogen are suggested.