Use of the nested polymerase chain reaction for detection of Toxoplasma gondii in slaughterhouse workers in Thika District, Kenya

Background. The widely used methods of diagnosis of Toxoplasma gondii are serological. Current reports indicate a high seroprevalence of T. gondii in humans in Kenya. There is a need for more sensitive diagnostic tests, especially when the specific antibody titres are below detectable threshold levels. Use of the polymerase chain reaction (PCR) targeting the repetitive 529 base pair loci has been reported to be sensitive and specific. Objective. To detect T. gondii in a high-risk group of public health workers in Thika District, Kenya. Methods. In total, 87 human blood samples were collected from male slaughterhouse workers between  1 March 2013 and  25 June 2013. The DNA extracted was amplified by the nested PCR. Results. T. gondii was detected in 39.1% (34/87) of the workers. In the cow-sheep-goat slaughterhouses the prevalence ranged between 20% and 60%, while all the chicken slaughterhouse workers (6/6, 100%) tested positive. The difference in T. gondii positivity between the workers in the chicken slaughterhouse and those in the cattle-sheep-goat slaughterhouses was statistically significant ( p =0.003). Conclusion. This study shows the presence of T. gondii in an asymptomatic high-risk group in Thika District, indicating the need for enhancement of public health awareness.