Seroprevalence and Factors Associated with Infection with Toxoplasma gondii in Iquitos and Lima, Peru

Abstract

Toxoplasma gondii infection can pose a significant health risk, particularly among immunocompromised individuals, such as people living with HIV (PLHIV). This study aimed to evaluate the seroprevalence of T. gondii and associated factors among PLHIV and individuals who are HIV negative in two distinct regions of Peru: Iquitos and Lima. We conducted a cross-sectional study, enrolling 281 participants (100 PLHIV and 181 HIV-negative participants). An in-house ELISA was used to detect IgG antibodies against T. gondii after ensuring that its performance was comparable with the commercially available Vircell ELISA kit. Our in-house ELISA demonstrated high reliability, with a positive agreement of 98.3% and a negative agreement of 100% with the Vircell ELISA kit. The overall seroprevalence of T. gondii was 62.3%, with significantly higher rates observed in Iquitos (88.0%) than in Lima (29.3%). People living with HIV showed a notably higher prevalence ratio (PR) for T. gondii seropositivity in both cities, with PRs of 1.18 (95% CI, 1.07–1.29) in Iquitos and 2.29 (95% CI, 1.30–4.05) in Lima. This study highlights the significant regional disparities in T. gondii seroprevalence between Iquitos and Lima, which may be driven by environmental and socioeconomic factors. Our findings underscore the need for region-specific public health interventions to mitigate the impact of T. gondii infections in PLHIV in Peru. Enhanced public health strategies, including improved access to clean water and sanitation in high-risk areas like Iquitos, may be important to reduce the burden of T. gondii and prevent severe complications in vulnerable populations. Copyright © 2025 American Society of Tropical Medicine and Hygiene.