Toxoplasma gondii parasites present strong but geographically varied signatures of population structure. Populations sampled from Europe and North America have commonly been defined by over-representation of a small number of clonal types, in contrast to greater diversity in South America. The occurrence and extent of genetic diversity in African T. gondii populations remains understudied, undermining assessments of risk and transmission. The present study was designed to establish the occurrence, genotype and phylogeny of T. gondii in meat samples collected from livestock produced for human consumption (free-range chickens, n = 173; pigs, n = 211), comparing with T. gondii detected in blood samples collected from seropositive pregnant women (n = 91) in Benue state, Nigeria. The presence of T. gondii DNA was determined using a published nested polymerase chain reaction, targeting the 529 bp multicopy gene element. Samples with the highest parasite load (assessed using quantitative PCR) were selected for PCR-restriction fragment length polymorphism (PCR-RFLP) targeting the surface antigen 3 (SAG3), SAG2 (5’ and 3’), beta-tubulin (BTUB) and dense granule protein 6 (GRA6) loci, and the apicoplast genome (Apico). Toxoplasma gondii DNA was detected in all three of the populations sampled, presenting 30.6, 31.3 and 25.3% occurrence in free-range chickens, pigs and seropositive pregnant women, respectively. Quantitative-PCR indicated low parasite occurrence in most positive samples, limiting some further molecular analyses. PCR-RFLP results suggested that T. gondii circulating in the sampled populations presented with a type II genetic background, although all included a hybrid type I/II or II/III haplotype. Concatenation of aligned RFLP amplicon sequences revealed limited diversity with nine haplotypes and little indication of host species-specific or spatially distributed sub-populations. Samples collected from humans shared haplotypes with free-range chickens and/or pigs. Africa remains under-explored for T. gondii genetic diversity and this study provides the first detailed definition of haplotypes circulating in human and animal populations in Nigeria.

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Free-range chickens play a vital role in the epidemiology of toxoplasmosis because they feed on the ground, exposing them to infective oocysts shed by cats that contaminate the environment. The role of chickens in the epidemiology of toxoplasmosis in Nigeria is understudied. Therefore, in the present study, we surveyed 222 free-range chickens slaughtered for human consumption in Kaduna metropolis, Nigeria, for the presence of anti-T. gondii antibodies using indirect enzyme-linked immunosorbent assay (iELISA). Of the total birds sampled, 27.9% (62/222) were seropositive. Results showed no statistically significant association between seroprevalence and sex (p > 0.05). The study has demonstrated the presence of anti-T. gondii antibodies in free-range chickens in Kaduna, Nigeria, indicative of exposure of the sampled chickens to T. gondii oocysts. Proper cooking of poultry meat obtained from the study location is advocated to avoid exposure to T. gondii.