Shedding proportion of Toxoplasma gondii-like oocysts in feral cats and soil contamination in Oyo State, Nigeria

Abstract

Toxoplasmosis, a disease caused by the intracellular protozoan parasite Toxoplasma gondii, is transmitted through several hosts with cats serving as its definitive host. Oocysts are released with cat faeces into the environment ( e.g. soil); an important medium in its transmission. The level of soil contamination with oocysts is an indicator of the level of on- going transmission. However, a dearth of information exists on the relationship between the presence of oocysts shedding cats and soil, and its importance in the transmission of T. gondii in Nigeria. In this study, the shedding proportion of T. gondii-like oocysts in cats and soil contamination levels were investigated in three communities in Ibadan, Nigeria. Soil ( n = 204) and feral cat faecal samples ( n = 14) were examined for the presence of oocysts using a modified sucrose flotation technique. Cat sera ( n = 15) were also analysed for IgG antibodies to T. gondii by ELISA. T. gondii-like oocysts were identified in 21.4% (95% CI: 4.6–50.8) of the total cat faecal samples. The prevalence was 50% (95% CI: 6.7–93.3), 0% and 10% (95% CI: 0.3–44.5) in Akinyele, Laniba and Ajibode communities respectively. T. gondii IgG antibody was present in 86.7% of the screened cat sera (including the copropositive cats). The seroprevalence in cats was 75% in Akinyele, 0% Laniba and 90.9% for Ajibode community ( P >0.05). Oocysts were recovered from 1.5% (95% CI: 0.50–4.23) of the soil samples screened and were identified from 3.8% (95% CI: 0.13–10.58) of the soil collected in Akinyele community. Akinyele also recorded the highest number of infected cats. Oocysts were identified in soil from dumpsites 2.6% (95% CI: 0.4–13.2) and residential areas 1.9% (95% CI: 0.5–6.8). Soil contaminated with T. gondii-like oocysts and cats shedding oocysts were found in areas with high human activities within the communities. The presence of T. gondii-like oocysts in the soil and the presence of cats that tested positive to antibodies specific to T. gondii MIC 3 Protein suggested the possibility of T. gondii transmission in these communities and places emphasis on its public health importance in a susceptible population.