Molecular detection and partial B1 gene sequence analysis of Toxoplasma gondii in free-range chickens, pigeons, and guinea fowl from the Federal Capital Territory, Nigeria

Toxoplasma gondii is a globally distributed zoonotic protozoan of major public health and food safety significance. Despite a documented T. gondii seroprevalence of 26.8% among women of reproductive age in Nigeria, the animal reservoir of infection in the Federal Capital Territory (FCT) had not previously been investigated. A cross-sectional study collected brain, heart and thigh muscles from 162 free-range birds (102 chickens, 30 pigeons, and 30 guinea fowl) across all six FCT area councils during the rainy (August-October 2025) and dry (November 2025-February 2026) seasons. Semi-nested PCR targeting the B1 gene was performed, and representative positive amplicons were Sanger-sequenced and compared with reference sequences. Toxoplasma gondii DNA was detected in 22 of 162 birds (13.6%; 95% CI: 9.1–19.7%). Prevalence was 16.7% in chickens, 10.0% in pigeons, and 6.7% in guinea fowl, with no significant inter-species ( p = 0.384) or inter-council ( p = 0.770) differences. Season showed the strongest association with infection, with prevalence significantly higher ( p < 0.001) during the rainy season (24.7%) than the dry season (2.5%). PCR-positive chickens had significantly lower body weight than PCR-negative chickens ( p < 0.001), a similar direction of difference was observed descriptively in pigeons and guinea fowl, though positive subgroup sizes were too small for formal inferential testing. Sequence comparison revealed 100% nucleotide identity among FCT sequences (GenBank accession [PZ576184], T6 [PZ576185] and T7 [PZ576186]), which showed minimal divergence from previously reported chicken-derived sequences from Plateau State, Nigeria, and from B1 gene sequences reported from several other countries. In conclusion, this study establishes for the first time that T. gondii DNA was detected in free-range chickens, pigeons, and guinea fowl across the FCT. These findings support consideration of avian T. gondii infection within zoonotic disease surveillance programmes in the FCT under a One Health framework.