We have come a long way in the battle to stem the HIV/Aids tide. Increasing numbers of those infected believe in a better future as the government rolls out antiretroviral drugs and expands its programmes to all corners of the country.But there is a problem that if not tackled will reverse the gains we have made.We have lowered our guard, and while there has been a slight decline since 2005, the rate of new infections is on the increase.The Aids conference in Durban this week heard a shocking statistic - more than half a million South Africans contracted HIV last year, and the number is rising.Many of the new infections were in the 15-24 age group, particularly girls.The war against HIV/Aids will only be won if we significantly reduce the number of new infections and improve the treatment of those infected.The current trend will require more funding from the government as the number of people in need of antiretrovirals increases.While our politicians have every reason to be upbeat about HIV treatment programmes, we should all be concerned about the rate of infection.We lead the world when it comes to supplying antiretrovirals, but this means nothing when more and more young people get infected.There was, however, some good news from the conference.We have made significant progress in eradicating mother-to-child transmission of HIV .And Health Minister Aaron Motsoaledi said that soon South Africans will get their medication from self-service "pharmacy dispensing units". These machines will help to prolong the lives of those infected.But we need to invest more resources and time to change the sexual behaviour of South Africans.The best way to fight the Aids pandemic is not to be infected...