Prevalence of intestinal parasites in HIV-positive patients on the island of Bioko, Equatorial Guinea: its relation to sanitary conditions and socioeconomic factors.

The prevalence of intestinal parasitic diseases and their associated factors has been investigated in HIV populations from the Island of Bioko, Equatorial Guinea. The feces of 310 participants from the island of Bioko (260 HIV-positive and 50 HIV-negative) were analyzed by microscopic observation. Immunochromatography was also used to diagnose Giardia, Entamoeba histolytica and Cryptosporidium spp. In addition, patients were asked for sociodemographic, economic and academic status, and CD4+ T cell counts were recorded. For HIV-positive patients, the prevalence of infection by intestinal parasites was 81.5% (212/260), 83.8% (218/260) by pathogenic helminths and 55.4% (168/260) by pathogenic protozoa (E. histolytica/dispar and Giardia duodenalis). Gender association was found between the infection by Ascaris and Schistosoma, a higher proportion being found in women; and between Entamoeba and the place of residence, a higher proportion being observed in the urban belt. Strongyloides stercoralis and Chilomastix mesnili appeared only in the people of this group, all the cases of Chilomastix being in females. For HIV-negative participants, the prevalence of infection by intestinal parasites was 74.0% (37/50), 90.0% (45/50) by pathogenic helminths and 66.0% (43/50) by pathogenic protozoa. Gender, educational level and low hygiene were associated with intestinal parasitic infection. When comparing the two groups (HIV-positive and HIV-negative), statistical association between HIV co-infection and infection by Giardia and Entamoeba was found. Diarrhea was also associated with intestinal parasitic infection in the HIV-positive group. Not only do our findings reflect high rates of intestinal parasitic infections in HIV-positive people, but also in the HIV-negative group, suggesting a closer relationship between sanitary status and living conditions than with immune status, and thus they highlight the need to carry out health education policies in the population. In addition, Schistosoma intercalatum/guineensis has been detected for the first time as an autochthonous parasite on the island.