A low-cost antibiotic should be given to all children with HIV in developing countries to prevent infections such as pneumonia and reduce deaths, scientists have said.
Dr Diana Gibb of the Medical Research Council and her colleagues said a trial involving HIV-infected children in Zambia was stopped early because it was so successful.
A daily dose of the drug co-trimoxazole nearly halved the death rate in youngsters taking it compared to those given a placebo. Children in the study were between one and 14.
"We believe that our results can be generalised to a policy that could be applied universally to children with clinical features of HIV infection in Africa and elsewhere," Dr Gibb said.
She and her team, who reported the findings in the Lancetmedical journal, said they believe all children should receive the drug, regardless of their age or CD4 count - which measures immune system cells in the blood.
HIV destroys the immune system and leaves the body vulnerable to a variety of life-threatening diseases, so-called opportunistic infections, such as tuberculosis or pneumonia.
"Co-trimoxazole in resource-limited settings where there are a lot of infections for children is certainly something that could have an impact on their quality of life, hospital admissions and mortality," Dr Gibb said.
The researchers tested the drug in a trial of 541 children infected with HIV in Zambia. The youngsters were randomly selected to receive the treatment or a placebo and followed up for 19 months.
Twenty-eight per cent of children in the drug group died, compared to 42 per cent who had been given the placebo.
"Nutritional support and co-trimoxazole could definitely have an impact while waiting to see if anti-retrovirals can be rolled out," Dr Gibb added. Anti-retrovirals are a class of drugs that are used to fight HIV/AIDS. She said it would cost about $10 a year to provide co-trimoxazole for a child.
About 38 million adults and children worldwide are living with HIV, according UNAIDS, the Joint United Nations Programme on HIV/AIDS. The majority of cases are in sub-Saharan Africa. Access to universal treatment is a major goal in the battle against the global epidemic.