HIV/Aids

Updated 30 March 2016

How circumcision reduces HIV risk

The procedure reduces bacteria, affecting how body fights Aids virus, researcher says.

6

A study reveals that circumcision affects the type of bacteria that live on the penis, which could explain why circumcised men have a 50% to 60% reduced risk of being infected by HIV, the virus that causes Aids.

Circumcision also lowers the risk of infection with other sexually transmitted viruses such as human papillomavirus and herpes simplex virus type 2, researchers have found.

Instead of viruses, however, this study looks another type of microbe: bacteria.

How the study was done

In this study, researchers assessed the numbers and types of bacteria on the penis before and after circumcision.

One year after the procedure, there was a significant decline in the total number of bacteria, a drop in the number of anaerobic bacteria (which thrive in locations with limited oxygen), and a slight increase in the number of aerobic bacteria.

"The change in the communities is really characterised by the loss of anaerobes. It's dramatic," study corresponding author Lance Price, of the Translational Genomics Research Institute in Arizona and George Washington University, said in a news release from the American Society for Microbiology.

"From an ecological perspective, it's like rolling back a rock and seeing the ecosystem change. You remove the foreskin and you're increasing the amount of oxygen, decreasing the moisture - we're changing the ecosystem," he explained.

The exact way that the bacterial community on the penis may affect the risk of HIV infection is not known, but previous research suggests that these bacteria may influence how susceptible the penis is to sexually transmitted viral infections, Price said.

In uncircumcised men, a higher number of bacteria may activate cells in the foreskin called Langerhans cells, preventing them from carrying out their normal role of fighting off viruses.

Instead, the activated Langerhans cells may actually help HIV infect the immune system, according to Price.

He said the circumcision-related reduction in the number of bacteria on the penis could prevent the Langerhans cells from doing this.

This research could lead to non-surgical alternatives to circumcision that would alter the bacterial community on the penis and reduce the risk of HIV infection in men, Price said.

Watch: Medical Male Circumcision - HIV Prevention from CareWorks on Vimeo.



Read more:

SA needs to be educated about male circumcision
Male circumcision lowers HIV risk for women
How a foreskin ups HIV risk

Copyright © 2016 HealthDay. All rights reserved.

 

Read Health24’s Comments Policy

Comment on this story
6 comments
Comments have been closed for this article.

Ask the Expert

HIV/Aids expert

Dr Sindisiwe van Zyl qualified at the University of Pretoria before working for an HIV/AIDS NPO in Soweto for many years. She was named one of the Mail & Guardian's Top 200 Young South Africans in 2012.

Still have a question?

Get free advice from our panel of experts

The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.

* You must accept our condition

Forum Rules