Detection of Natural Toxoplasma gondii Infection in Chicken in Thika Region of Kenya Using Nested Polymerase Chain Reaction

The detection of Toxoplasma gondii in free-range chickens is a good indicator of possible risk to human beings. The aim of this study was to investigate the occurrence of T. gondii in free-range chicken using polymerase chain reaction (PCR). Brain samples from 105 free-range chickens from three administrative areas in Thika region, Kenya, were collected, DNA-extracted, and analyzed using PCR to detect presence of T. gondii. The overall prevalence of T. gondii in all the three areas was 79.0% (95% CI: 70.0-86.4%) and the prevalence across the three areas was not significantly different (P = 0.5088; χ 2 = 1.354). Female chickens had higher (79.4%) prevalence than males (78.6%), although the difference was not significant (P = 0.922, χ 2 = 0.01). However, chickens that were more than 2 years old had significantly (P = 0.003; χ 2 = 11.87) higher prevalence compared to younger ones. The study indicates that there was a high occurrence of T. gondii infection in free-range chickens from Thika region and that the infection rate is age dependent. Further studies should be carried out to determine the possible role of roaming chickens in the epidemiology of the disease among humans in the area.