Prevalence of Enteric Protozoa in Human Immunodeficiency Virus (Hiv)–positive and Hiv-Negative Men Who Have Sex With Men From Sydney, Australia

Abstract

A prospective, comparative study of the prevalence of enteric protozoa was determined among human immunodeficiency virus (HIV)- positive and HIV-negative men who have sex with men (MSM) in Sydney, Australia. A total of 1,868 patients submitted stool specimens; 1,246 were from MSM (628 HIV positive and 618 HIV positive) and 622 from non-MSM were examined over a 36-month period. A total of 651 (52.2%) stool specimens from MSM were positive for protozoa compared with 85 (13%) from non-MSM. There was a significant difference in the prevalence of Blastocystis hominis, Endolimax nana, Entamoeba histolytica/dispar complex, Entamoeba hartmanni, Iodamoeba butschlii, and Enteromonas hominis detected between MSM and non-MSM (P<0.001). The only notable difference between HIV-negative and HIV-positive MSM was that HIV-infected MSM were found to more likely have a Cryptosporidium parvum infection. Entamoeba histolytica was found in 3 patients, E. dispar in 25, and E. moshkovskii in 17, all of whom were MSM. When compared with a control group, MSM were significantly more likely to harbor intestinal protozoa and have multiple parasites present. The results of this study show high rates of enteric parasites persist in MSM and highlight the importance of testing for intestinal parasites in MSM. This is the first report of E. moshkovskii from MSM.

Invasive Amebiasis in Men Who Have Sex with Men, Australia

“…Recent reports from a number of these coun-tries, however, suggest that invasive amebiasis is emerging as an increasingly common infection, specifi cally in the MSM population (2-6). MSM have a higher risk than others for intestinal parasite carriage; not only are they substantially more likely to harbor intestinal protozoa, but they are also more likely to harbor multiple parasites (11). These protozoa are transmitted by the fecal-oral route; high rates of oral-anal sex by MSM are considered the reason for increased rates of carriage.…”

HIV/AIDS-Associated Opportunistic Protozoal Diarrhea

“…2,30,31 This is supported by a recent prospective, comparative study comparing the prevalence of enteric protozoa among HIVpositive and HIV-negative men in Australia. 2,32 A total of 1,868 inpatients submitted stool specimens over a 36-month period to determine the presence of enteric parasites. 2 In this study C. parvum cases occurred exclusively in HIV-positive patients.…”

Seroprevalence of Entamoeba histolytica Infection among Men Who Have Sex with Men in Sydney, Australia

“…15 A study from Sydney showed high rates of intestinal parasites in MSM, with 52.2% of stool specimens positive for protozoa, compared with 13% from non-MSM, of which E. histolytica had a prevalence rate of 0.24% in the MSM group. 16 Another report of five cases of invasive amebiasis in MSM from Sydney further documents its existence in this at risk group. 17 Accurate prevalence and incidence data for E. histolytica are difficult to ascertain by microscopy alone, because it is morphologically indistinguishable, yet genetically distinct from non-pathogenic amoebic species; including Entamoeba dispar and Entamoeba moshkovskii .…”