Seroprevalence and molecular detection of Toxoplasma gondii infections in rodents and cats in Mbeya District, Tanzania

Abstract

Toxoplasmosis is a zoonotic disease that is increasingly becoming an important but neglected disease of global concern. Cats and other feline species are the definitive host while rodents are the reservoirs of Toxoplasma gondii the causative agent of the disease. The study aimed to establish both Toxoplasma infection and exposure status in rodents and cats in Mbeya District, Tanzania. A cross-sectional study was employed where a total of 300 rodents and 52 cats were obtained from purposively selected wards in Mbeya district. To establish the infection statutes the serum and brain tissue in rodents and cats were collected for laboratory analysis. Indirect ELISA (ID.vet Innovative Diagnostics-France) was employed to determine T. gondii infection status in sera where seropositive samples and some of cat seronegative sample were subjected to conventional PCR analysis targeting GRA 6 gene for confirmation of the infection. Serological assay detected exposure status in 8.7 % (95% CI=0.057-0.124) of the rodent’s serum samples and none in cats. PCR assay confirmed the infection in five of the rodent seropositive samples and one seronegative cat sample. Most of the seropositive samples belonged to Rattus rattus the most abundant (57%) rodent species captured in households and storage facilities. No significant variations in seroprevalence were found between locations, sex, species, or habitats. It is concluded that the study established the exposure status and actual infection of T.gondii in rodents in the study area and that R. rattus were the most exposed and infected. This highlights the risk of transmission of the infection to humans given the possible interaction with rodents in houses and stores where they were commonly trapped. The community health education on aspects of disease transmission, clinical signs and disease management is recommended. Furthermore, a regular animal and human screening for the disease to reveal its epidemiological patterns is also recommended.