Seroprevalence and molecular detection of toxoplasma gondii infection in rodents and pigs and risk factors for human exposure in Iringa municipality, Tanzania

Loading...
Thumbnail Image

Date

2024-04

Journal Title

Journal ISSN

Volume Title

Publisher

Sokoine University of Agriculture

Abstract

Toxoplasma gondii is one of the protozoan parasites of worldwide distribution causing infection to various warm-blooded animals. The parasite's life cycle requires both primary and intermediate hosts. Notably, rodents and pigs are significant intermediate hosts due to their frequent contact with humans, thereby assuming a pivotal role in the public health implications of the disease. Mortalities due to Toxoplasmosis have been documented in southern highland regions including the Iringa region. However, there is a lack of information on the disease status in rodents and pigs and risk factors for human transmission in the Iringa region. This study aimed at establishing the seroprevalence and molecular detection of T. gondii infection in rodents and pigs and risk factors associated with human exposure in Iringa municipal in Tanzania. A cross-sectional study design was adopted. The study wards were randomly for rodent sampling and questionnaire survey. Blood samples were collected from both rodents and pigs; in addition, brain samples were obtained from rodents. The antibody ELISA technique was employed on rodent and pig samples and seropositive samples were subsequently subjected to molecular detection. The rodent brain samples were also used in molecular analysis which is considered the most susceptible part of infection for the parasite and pig blood samples were used targeting the B1 gene at 530bp by nested PCR. Obtained T. gondii DNA was further sent for sequencing. A total, of 127 rodents and 240 pigs were sampled, while the questionnaire survey involved 143 participants who either reported complaints of rodent infestation in their homes or kept pigs. The overall T. gondii infection seroprevalence for rodents and pigs was 1.57% and 26.25%, respectively. Seropositive rodents originated from Kitwiru ward, seropositivity was predominantly associated with Mastomys natalensis, while seropositive results were found across all surveyed wards for pigs. The statistical analysis showed a significant correlation between seropositivity and rodent species (df= 2, χ2=6.2926, p=0.043). However, no significant correlation was found between seropositivity and sex in either rodents or pigs. T. gondii DNA was detected from all two seropositive rodents and two out of the sixty-three seropositive pigs. Sequences from this study formed phylogenetic linkage when compared with other sequences from different animals including humans from other parts of the globe with the highest homology percentage of 99.15%. However, the questionnaire survey showed an inadequate level of awareness of about 30.1%, exposure to cat feces without gloves, keeping cats at their homes, and mishandling of abortion cases in livestock were identified as risk factors for disease transmission in humans in the study area. Detection of antibodies against T. gondii infection in a notable proportion of rodents and pigs, coupled with the subsequent identification of its DNA within both animal species samples, indicates the potential public health implications of these animals in the study area. Moreover, the observed inadequate awareness about toxoplasmosis amplifies the risk of disease transmission among the community. Consequently, it is crucial to implement effective strategies to safeguard the community from this neglected but serious disease.

Description

MSc. Dissertation

Keywords

Toxoplasma gondii, Rodents, Pigs, Risk Factors

Citation