Bangkok – The male condom is still the most effective intervention to prevent HIV transmission   – but it relies on men’€™s willingness to use it to protect themselves and their partners.

In an overview of available measures to prevent HIV presented to a full plenary session of the International AIDS conference, University of KwaZulu-Natal epidemiologist Dr Quarraisha Abdool Karim focused on the role of condoms, antiretrovirals and male circumcision.

‘€œConsistent condom use reduces HIV incidence by at least 80 percent,’€ said Karim. In pregnancy prevention condoms were 86 to 97 percent effective.

However, for this to happen, reliable access to condoms was essential. Karim said that in the public sector, South Africa had increased condom availability from 250 million in 2000 to 267 million in 2001 to an estimated 350 million in 2002. Further condoms were distributed through social marketing and the private sector.

Female condoms had become available in the past decade as an additional barrier method. Karim said several studies showed that they were as effective as male condoms to prevent sexually transmitted infections and pregnancy. However, they were more expensive to procure and far less widely available than male condoms.

Increased access to antiretroviral therapy could also play a vital role in preventing HIV transmission between discordant couples ‘€“ where one person is infected and the other is not.

Karim said that given that a large amount of HIV in the bloodstream increased the risk of transmission and that antiretroviral therapy had the effect of reducing this viral load, the ‘€œscale-up and increasing access to voluntary counselling and testing and Highly Active Antiretroviral Therapy (HAART) creates a new opportunity to integrate prevention and care.’€

She said that various mathematical models showed that antiretroviral therapy reduced HIV by up to 80 percent.

However, she warned that if adherence to HAART was poor, it could lead to increased drug resistance and complicate the therapy as new drug combinations would be needed.

Karim said there was inconclusive evidence to suggest that circumcised men might be at a lower risk of HIV infection than uncircumcised men.

A large study of discordant couples from Uganda showed that HIV incidence was zero percent among circumcised men compared to 16.7 percent in those who were not circumcised. But she stressed that this evidence was not sufficient to promote male circumcision as a public health intervention.

Karim said there were three Phase III trials underway in Kenya, Uganda and South Africa and these results would need to be considered carefully before any decisions were taken.

E-mail Sue Valentine