Opportunistic intestinal parasites in immunocompromised patients from a tertiary hospital in Monterrey, Mexico

Opportunistic parasites are still important agents causing morbidity and mortality in immunocompromised patients, particularly those living with HIV/AIDS. Few studies in Mexico have attempted to determine the prevalence of opportunistic intestinal parasites causing diarrhea in immunocompromised patients. A study was conducted to determine the intestinal parasites in HIV-positive and HIV-negative immunocompromised patients with diarrhea admitted to a tertiary care hospital in Monterrey, Mexico, from 2014 to 2015. Stool samples were examined for trophozoites, cysts, and eggs using the EGRoPe sedimentation-concentration technique and special techniques (modified Ziehl-Neelsen stain, modified trichrome stain). A total of 56 patients were included. The overall prevalence of intestinal parasitism was 64% (36/56); 22/36 patients were HIV-positive. Prevalence of opportunistic parasites was 69% in HIV-infected patients compared to 44% in HIV-negative patients (P = 0.06). Microsporidia were the most frequently identified parasites (24/36, 67%), followed by Cryptosporidium sp. (6/36, 17%), Sarcocystis sp. (4/36, 11%), Cystoisospora belli (3/36, 8%), and Cyclospora cayetanensis (1/36, 3%). Overall prevalence rates of microsporidiosis and cryptosporidiosis were 43% and 11%, respectively. Among HIV-infected patients, prevalence rates of microsporidiosis and cryptosporidiosis were 48% and 14%, respectively. We also report the first cases of intestinal sarcocystosis in Mexico, all in HIV-infected patients. In conclusion, microsporidia and coccidia are major parasitic agents causing diarrhea in immunocompromised patients, particularly HIV-infected patients.