Malaria-attributable fraction of fever episodes among HIV-seropositive patients in the Western highland area of Cameroon

Abstract

Background: Fever is the most frequent symptom for Malaria and HIV/AIDS, but it is non-specific; therefore it can’t be used efficiently in clinical diagnosis of malaria in hyperendemic zones. In hypoendemic areas of malaria, this assertion is not obvious, since people lack naturally acquired immunity. The present study aims at determining the Malaria-attributable fraction of fever episodes (MAFE) among HIV-positive patients in a hypoendemic highland area. Methods: During two-years prospective cross-sectional study, blood samples were collected from outpatients of an HIV/AIDS clinic and examined for the presence and density of malaria parasites. In addition to malaria related symptoms, some other patients’ data were recorded: sexe, age, body mass index (BMI), T-lymphocyte CD4 counts, viral loads, haemograms and transaminases measurements. Results: A total of 729 HIV-seropositive patients were enrolled into the study. Their mean Plasmodial infection rate and parasitaemia were: 0.823% and 1.050 parasites/µl of blood respectively; and were both significantly lower, compared to the control seronegative group, in contrast to our hypothesis. No significant difference was observed when the mean values of transaminases were compared between those with and without plasmodial infection. For the 119 (16.32%) febrile individuals found, the calculated MAFE was almost null (0.15%). Their mean CD4 count, red blood cells (RBC) count and haemoglobin rate were: 226 cell/µl, 3.83x10 6 RBC/µl and 10.4 g/dl respectively; and were all significantly lower than in the non-febrile group. However, malaria parasite infection rates and mean densities were similar in both groups. Likewise, there was no difference between: sex ratios, mean ages, BMI, total white blood cells counts and viral loads between the two groups. Conclusion: HIV infection in spite of the immunodeficiency induced does not enhance the risk of Plasmodium infection in hypoendemic highland settings. Even in the scarce cases of co-infection occurring here, malaria is rarely responsible for fever episodes. These fevers are indeed associated with higher anaemia and immunodeficiency, and likely due instead to opportunistic infectious diseases.