Serological and molecular detection of toxoplasma gondii and Risk factor analysis among the human population of Lahore, Pakistan.

INTRODUCTION

Toxoplasma gondii has a global epidemiology as a common apicomplexan parasite that affects homoeothermic vertebrates, including humans. It is believed that over one billion individuals are infected globally. The study aimed to determine the seroprevalence and molecular detection of T. gondii among residents of Lahore, Pakistan, and to identify associated demographic and behavioral risk factors.

METHODS

A cross-sectional study was conducted in which a total of 800 participants from Lahore were included. Blood samples were collected for serological testing using the Latex Agglutination Test (LAT) and the IgM-specific ELISA whereas molecular detection and genetic characterization were performed on 26 ELISA-positive samples using PCR amplification and SAG1 gene sequencing. Demographic, behavioral, and environmental risk factors were assessed through structured questionnaires. Statistical analyses were conducted using SPSS v26, with significance set at p ≤ 0.05.

RESULTS

The result revealed LAT positivity was 55.5%, whereas ELISA detected 5.9% IgM-positive cases. PCR confirmed active infection in 2 individuals, with rare co-positivity. Higher seroprevalence was observed in females, adults aged 30-49 years, participants with lower education, and those practicing boiled water consumption or owning pets. Notably, fruit and vegetable washing practices were significantly associated with both serological and PCR positivity (p < 0.01). Genetic analysis identified Type I T. gondii strains closely related to the Tg3-DRC-Eg reference strain.

CONCLUSION

The present study demonstrates the complementary roles of serological and molecular assays for accurate detection of T. gondii. Key demographic and behavioral factors, particularly hygiene and food-handling practices, influence local infection risk.