A trial of a compound extracted from seaweed that was thought to prevent the spread of HIV has proved disappointing.

According to a report in The Lancet, more than 6,000 people HIV negative women living in South Africa took part in a two-year study into whether a gel containing a carrageenan-based compound would protect them from infection.

Researchers Stephanie Skoler-Karpoff and Barbara Friedland said that work on prevention among heterosexual women would continue.

“This study did not show Carraguard’s efficacy in prevention of male-to-female transmission of HIV, although no safety concerns were recorded,” they wrote.

“Low levels of gel use could have compromised the potential to detect a significant protective effect.

“Although the results from this and other completed microbicides efficacy trials have been disappointing, the search for female-controlled HIV-prevention methods must continue.”

According to the UNAIDS 2008 report, The global percentage of people living with HIV has stabilised since 2000.

However, the overall number of people living with HIV has increased as a result of the ongoing number of new infections each year and the beneficial effects of more widely available antiretroviral therapy.

Sub-Saharan Africa remains most heavily affected by HIV, accounting for 67% of all people living
with HIV and for 72% of AIDS deaths in 2007.

Globally, there were an estimated 33 million people living with HIV in 2007.