Circumcision cuts HIV risk

In terms of infectious disease, Aids is the biggest killer in Africa, with HIV frequent in the sexually-active populations of many countries.

But the study, carried out by European and African researchers, found that uncircumcised men were at least three times more likely than circumcised men to contract the virus.

They looked at four cities, from different parts of the continent, and noticed marked differences in the incidence of HIV.

Not just sexual behaviour

This, said researchers, could not be explained away simply by differences in sexual behaviour.

However, in some of the cities, circumcision, in which the skin covering the tip of the penis is removed, was far more common, and these had far lower rates of HIV.

Anne Buve, an epidemiologist at the Insititute of Tropical Medicine in Antwerp, said: "We did find that circumcision confers certain protection against HIV, in that it seems circumcised men do not get HIV as easily as uncircumcised men."

Although the reason for the extra protection has not been proved, the research team suspects that the skin on the glans of the circumcised penis is tougher than that of the foreskin.

It is therefore less likely to suffer small abrasions which increase the chances of HIV being transmitted.

The study focused on Benin's capital Cotonou and Cameroon's capital Yaounde, where circumcision is a widespread cultural practice.

These towns were compared with Ndola in Zambia, and Kisumu in Kenya, where it is not.

Maina Kahindo, another researcher, urged Kenyan health authorities to act.

He said: "Both at national level and at ethnic leadership level, the issue of circumcision needs to be discussed and encouraged."