Opportunistic intestinal parasitic infections in immunocompromised (HIV/ AIDS) patients

Gastrointestinal parasitic infection is a major source of disease in people living with HIV/AIDS, especially in tropical countries. Diarrhoea is a common clinical manifestation of patients with HIV infection. Although gastrointestinal diseases occur in all age groups of immunocompromised patients, they occur with the greatest frequency (up to 90%) in patients with AIDS. Most of morbidity and mortality of advanced AIDS is associated with opportunistic intestinal parasites that cause debilitating infections in immocompromised individuals with low immune status as compared to the immunocompetent individuals. Protozoa are the most common cause of parasitic diarrhoea particularly in developing countries. They are frequently transmitted by unhygienic habits such as direct transfer of ova or cysts from anal region to mouth, eating with unwashed hands, eating and drinking of contaminated food and drink and inappropriate disposal of night soil and human excreta. Most common enteric opportunistic parasites which have been associated with HIV/AIDS include: Cryptosporidium spp., Isospora belli, Cyclospora spp., Microsporidium spp., Strongyloides stercoralis, Giardia lamblia, Entamoeba histolytica. Amongst the opportunistic intestinal parasitic infections, intracellular coccidial protozoan parasites, Cryptosporidium and Isospora belli infection have been labeled as AIDS-defining illness and occur mostly at CD4 counts <200 cells/?l.