Effect of HIV-1 Serostatus on the Prevalence of Asymptomatic Plasmodium falciparum Parasitemia Among Children Less Than 5 Years of Age in Benin City, Nigeria

Background. Human immunodeficiency virus (HIV) infection and Plasmodium falciparum malaria are 2 of the gravest health threats in sub-Saharan Africa. Multiple repeat infections with the malaria parasite as seen in endemic areas are necessary to develop specific malaria immunity. HIV is an immunosuppressive virus and in children aged <5 years, development of malaria-specific immunity may be impaired and malaria parasite clearance in theory will be delayed; hence the predisposition to increased incidence of asymptomatic malaria or severe malaria. This cross-sectional study was carried out to examine associations between immunosuppression and asymptomatic malaria parasitemia (ASMP) in HIV-infected children aged <5 years in Benin City. Methods. One hundred seventy-nine asymptomatic HIV-1-positive and 179 age- and sex-matched HIV-1negative children aged <5 years were recruited. The malaria parasite was determined by Giemsa-stained blood film by certified microscopy while concomitant CD4 + count was estimated in the HIV-infected children. Results. The prevalence of ASMP in those who were HIV-infected of 34.1% was significantly higher than 17.3% in the HIV uninfected (P = .001). The prevalence of ASMP was highest (59.3%) among subjects who were severely immunosuppressed (CDC immunologic category 3). The prevalence of ASMP significantly increased with advanced immune disease in the subjects (P = .011). Severe (World Health Organization) clinical staging was also significantly associated with increased prevalence of ASMP (P = .031). The prevalence of ASMP is significantly higher among subjects not receiving cotrimoxazole, associated with threefold risk of having ASMP (P = .003: odds ratio = 3.5). Conclusions. ASMP is more common in HIV-positive children aged <5 years and is significantly associated with declining CD4 + T-cell count and severe clinical disease. There is a need for integration of HIV- and malaria