Epidemiology of infections with intestinal parasites and human immunodeficiency virus (HIV) among sugar-estate residents in Ethiopia

Intestinal parasitic infections could play an important role in the progres sion of infection with human immunodeficiency virus (HIV), by further distu rbing the immune system whilst it is already engaged in the fight against H IV. HIV and intestinal parasitic infections were investigated in 1239, rand omly selected individuals, aged 15-54 years, living on a sugar estate in ce ntral Ethiopia. Intestinal parasites were identified in faecal samples (one /subject) using direct, concentration, and (for Strongyloides stercoralis l arvae) Baermann methods. HIV serological status was determined using ELISA, with ELISA-positive samples confirmed as positive by western blotting. Mos t (70.1%) of the subjects were infected with at least one intestinal parasi te and 3.1% were seropositive (but asymptomatic) for HIV. The intestinal pa rasites identified in the study population were amoebic parasites (Entamoeb a histolytica/Enta. dispar) (24.6%), hookworms (23.8%), Ascaris lumbricoide s (22.2%), Trichuris trichura (19.5%), S. stercoralis (13.0%), Taenia sagin ata (4.5%), Giardia lamblia (3.0%), and Enterobius vermicularis (1.3%). Overall, the HIV-positives were no more or less likely to carry intestinal parasites than the HIV-negatives (76.2% v. 69.9%; P > 0.05). However, when each parasite was considered separately, amoebic parasites were found to be more common in the HIV-positives than the HIV-negatives (43.7% v. 24.0%; P (0.05). This difference remained significant in a multivariate analysis, af ter controlling for the socio-demographic characteristics of the study part icipants. In conclusion, there was moderate interaction between intestinal parasites and HIV at the asymptomatic stage of HIV infection. The observed association between amoebic and HIV infections requires confirmation in a p rospective study, allowing for the analysis of biological mechanisms involv ed in the association.