A rectal microbicide can be formulated as an enema to prevent HIV and possibly other sexually transmitted infections, according to a new study.
Enemas are commonly used by men who have sex with men (MSM) and transwomen (TW) before sexual intercourse.
But these groups are vulnerable to HIV and a host of other sexually transmitted infections because enemas - even those that use tap water - can seriously damage the thin tissue lining the rectum, allowing for easier transmission of harmful viruses and bacteria.
"A douche-based rectal microbicide that is safe and effective could play an important role by providing another HIV prevention option for these highly vulnerable groups," said Brandon Brown, an assistant professor in the School of Medicine at the University of California, Riverside in US who led the research project.
"In view of the expanding global HIV epidemics in MSM and TW, there is an urgent and immediate need for novel HIV prevention options, such as the douche-based rectal microbicides we propose, that can be readily incorporated into existing sexual practices," said Brown.
"While we conducted the study among MSM and TW in Peru, our findings may extend to these groups locally and globally," said Brown.
"Unfortunately, little is known about rectal douching practices among these groups and the damage such practices may cause," he said.
For the study, the team led by Brown examined during February 2012-February 2013 the prevalence of enema use among 415 MSM and 68 TW in Lima, Peru.
Participants completed a self-administered interview on rectal douching practices to inform rectal microbicide douche development.
In the previous 6 months, 18 per cent of participants reported rectal douching, and those who reported douching were mainly those who had some receptive sexual role.
"We found that men who douched prior to sex did it primarily for hygiene and pleasure. We should capitalise on these reasons to increase this practice and eventually include a rectal microbicide for HIV prevention," Brown said.
The study was published in the journal AIDS and Behaviour.
