Since the advent of human immunodeficiency virus infection, with its profound and progressive effect on the cellular immune system, a group of human opportunistic pathogens has come into prominence. Opportunistic parasitic infection can cause severe morbidity and mortality. Because many of these infections are treatable, an early and accurate diagnosis is important. This can be accomplished by a variety of methods such as direct demonstration of parasites and by serological tests to detect antigen and/or specific antibodies. However, antibody response may be poor in these patients and therefore immunodiagnostic tests have to be interpreted with caution.
Cryptosporidium parvum
,
Isospora belli
,
Cyclospora cayetanensis
, Microsporidia,
Entamoeba histolytica
and
Strongyloides stercoralis
are the commonly detected parasites. Detection of these parasites will help in proper management of these patients because drugs are available for most of these parasitic infections.
