Seroprevalence of IgM and IgG Antibodies to Toxoplasma infection in healthy and HIV-positive adults from Northern Nigeria

Abstract

Introduction: We examined the seroprevalence of toxoplasma infection in HIV-negative and -positive adults from Zaria, Northern Nigeria, and assessed its relationship with demographic, clinical, and immunological findings.

Methodology: In a six-month cross-sectional study undertaken in 2008, sera of 219 adults, including 111 consecutive HIV-infected adults and 108 healthy HIV-negative adult volunteers from Zaria, Northern Nigeria, were examined for IgG and IgM antibodies to toxoplasma by ELISA.  Clinical characteristics of the HIV-infected patients were documented. Differences in toxoplasma seropositivity between HIV-positive and negative adults were sought. The relationship between toxoplasma seropositivity and variables such as age, sex and antiretroviral (ART) status, as well as HIV clinical staging and CD4 cell counts were also determined. P<0.05 was considered significant.

Results: The seroprevalence of toxoplasma infection (IgG positive and or IgM positive) was 32.4% in HIV-negative healthy adults and 38.7% in HIV-infected adults (P>0.05).  The rate of IgM seropositivity was 4.6% in healthy adults and 1.8% in HIV-infected patients, while the rate of IgG seropositivity (without IgM seropositivity) was 28.7% in healthy adults and 37.8% in HIV-infected patients (p>0.05).  Toxoplasma seropositivity was not associated with age, sex, ART status, CD4 cell count or HIV clinical staging. Seventy-four percent of the toxoplasma seropositive HIV-infected patients were asymptomatic and no cases of toxoplasma encephalitis were identified.

Conclusion: Toxoplasmosis is equally prevalent in HIV-infected patients and healthy adults from similar environments in Northern Nigeria. It is imperative to develop public health policies to prevent toxoplasmosis in Nigeria, especially in HIV-infected patients.