Intestinal parasites in human immunodeficiency virus infected patients

ABSTRACT

Treatment of concurrent opportunistic and non-opportunistic infections is a priority in improving quality of life in HIV infected patients in developing countries. The objective of the study was to determine the prevalence of opportunistic intestinal parasites in persons with and without HIV infection in Honduras. It was based on study of 52 HIV-positive and 48 HIV-negative persons at the Social Security Hospital in San Pedro Sula. Data sheets recording age, sex, stool parasitology, HIV serology and clinical state of HIV infection were completed for each study participant. Cryptosporidium parvum and Strongyloides stercoralis, which are intracellular or live in the mucosa, were found exclusively in persons infected with HIV. In contrast, the prevalence of the extracellular parasites Giardia lamblia, Ascaris lumbricoides and Trichuris trichiura was significantly higher in persons who were HIV-negative. It appears that infection with HIV may selectively deter the establishment of some intestinal parasites. This may be due to HIV induced enteropathy which does not favor the establishment of extracellular parasites. However, intracellular and mucosal dwelling organisms may benefit from pathological changes and reduced local immune responses which are induced by the virus which, in turn, lead to higher prevalence among HIV-infected individuals. We further postulate that the switch from a Th-1 to a predominantly Th-2 response as HIV infection progresses to AIDS may lead to an environment which is unsuitable for parasite survival (AU)