Contraceptive gel could be used to stop spread of Aids

Women could soon be able to buy an "invisible condom" that will act both as a contraceptive and stop sexually-transmitted diseases, including HIV, which causes Aids.

Women could soon be able to buy an "invisible condom" that will act both as a contraceptive and stop sexually-transmitted diseases, including HIV, which causes Aids.

Two teams of American scientists are developing gel-based products for women which both kill sperm and also HIV and other microbe-borne diseases. One of the teams has recently completed tests in cats, which showed that the gel was effective against the feline form of HIV, called feline immunodeficiency virus.

If either team succeeds in getting the gel through human clinical trials, the market could be enormous. A survey last February found that in the United States roughly 21 million sexually active women would be interested in using such a gel.

Though most new cases of HIV occur in developing countries, there has also been a rise in cases in Britain and America. While condoms are nearly 100 per cent effective in blocking both HIV and sperm, women often find it difficult to insist that men use them.

Dr Alan Stone, who chairs the international working group on microbicides, said there has been a "positive trend" among pharmaceutical companies in thinking about microbicides and that some were considering making them.