Parasitic disease targets HIV-infected gay males

Washington, Nov 30 ( A rare parasitic disease, normally transmitted by contaminated water, has been shown to be transmitted by sex between HIV-positive men.

Taiwanese researcher Chieng-Ching Hung, who led the study, had received a doctorate from the University of Antwerp and the Institute of Tropical Medicine Antwerp (ITMA).

Amoebiasis, an infection with the single-celled amoeba Entamoebia histolytica, normally is very rare.

You only catch it in a few developing countries where the amoeba is endemic, and where hygiene is somewhat substandard, leading to contact with contaminated water

It only becomes dangerous when the amoeba invades your intestinal lining and causes a bloody diarrhoea, or when it enters the bloodstream, where it, among other things, causes liver abscesses. All in all, amoebiasis takes some 70,000 lives a year worldwide.

For some time now, physicians suspected the disease to be a bit overrepresented among HIV-positive male homosexuals.

But it was difficult to come to conclusions from small numbers, and in addition the classical diagnostic test (putting the stool under the microscope) was not really dependable.

Hung used modern molecular techniques, pinpointing the amoeba more precisely and, what’s more, showing which amoebas were closely related. In other words: who had got the infection from whom.

In Taiwan, seropositive (hiv-infected) gay men were shown to be infected much more often with the amoeba than the healthy population, and also than seropositive heterosexuals, said an ITMA release.

Also, Hung found men from different regions nevertheless to be infected by closely related amoebas. The most reasonable explanation is that the infection happened through homosexual (oral-anal) contact.