Front Vet Sci. 2026 Aug 14;13:1912990. doi: 10.3389/fvets.2026.1912990. eCollection 2026.
ABSTRACT
BACKGROUND: Toxoplasma gondii is a major zoonotic pathogen causing reproductive losses in sheep and posing significant public health risks, particularly through meat consumption and congenital infection. Despite Afyonkarahisar Province being one of the most important sheep-producing regions in Türkiye, no farm-level seroepidemiological study with structured risk factor analysis had previously been conducted there.
METHODS: A cross-sectional study was conducted between September and December 2025 on 550 sheep blood samples collected from 55 commercial farms across Afyonkarahisar Province. Anti-T. gondii antibodies were detected using a commercial indirect ELISA (ID Screen® Toxoplasmosis Indirect Multi-Species, IDvet), with samples classified as positive (sample-to-positive percentage [S/P%] ≥ 50%), doubtful (40%-50%), or negative (≤40%). A structured questionnaire was administered to collect 19 farm- and animal-level variables. Associations with seropositivity were evaluated by univariable analysis and a mixed-effects logistic regression model with farm as a random effect, with Firth’s penalized regression applied to obtain stable estimates where quasi-complete separation occurred.
RESULTS AND DISCUSSION: The overall animal-level seroprevalence was 42.2% (232/550; 95% CI: 38.0%-46.4%), and 44 of 55 farms (80.0%; 95% CI: 67.0%-89.6%) were classified as seropositive. In multivariable analysis using Firth’s penalized logistic regression, five variables were independently associated with higher seropositivity: flock-level history of abortion (aOR = 3.77; 95% CI: 2.41-6.00), age over 12 months (aOR = 3.54; 95% CI: 2.15-5.97), communal pasture use (aOR = 74.12; 95% CI: 10.22-9431.54, wide owing to quasi-complete separation), leaving aborted materials on site (aOR = 2.30; 95% CI: 1.49-3.61), and irregular barn cleaning (aOR = 2.32; 95% CI: 1.46-3.72). Cat presence was universal across all 55 farms, precluding statistical evaluation; however, stray cats had unrestricted access to feed and water on every farm, likely representing the primary driver of environmental oocyst contamination. Breed, sex, water source, and antiparasitic drug type were not significantly associated with seropositivity. T. gondii infection is highly endemic in sheep in Afyonkarahisar, with seroprevalence exceeding the national average. Stray cat access control, safe disposal of aborted materials, and routine differential diagnosis for abortifacient pathogens are recommended as priority interventions for reducing infection pressure and mitigating both animal health and public health risks within a One Health framework.
PMID:42666301 | PMC:PMC13521879 | DOI:10.3389/fvets.2026.1912990
