IT HAS been used for decades to treat minor infections, and a year鈥檚 treatment costs as little as $7. But the standard antibiotic cotrimoxazole last week earned a new and heroic role in the fight against childhood AIDS in Africa, preventing potentially lethal respiratory infections that strike HIV-positive children with weakened immunity.
Last week鈥檚 study in The Lancet (vol 364, p 1865) showed that when given regularly for 19 months to HIV-positive children aged from 1 to 14, the drug almost halved their risk of dying from secondary infections compared with children receiving a placebo. Some 42 per cent of the placebo-treated children died, compared with 28 per cent of those on cotrimoxazole. 鈥淭hat鈥檚 a 43 per cent reduction in mortality over 20 months,鈥� says Diana Gibb of the UK Medical Research Council鈥檚 Clinical Trials Unit in London, who led the team.
The World Health Organization and UNICEF were so impressed by the findings they have revised their advice to governments on how to tackle AIDS. 鈥淎ny child with a whisper of HIV, give them cotrimoxazole,鈥� says Siobhan Croxley, a paediatrics specialist at the WHO鈥檚 HIV/AIDS unit in Geneva, Switzerland.
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The trial on 541 children diagnosed with HIV took place at the University Teaching Hospital in Lusaka, Zambia, an area where resistance to the antibiotic is very common. Gibb and her colleagues wanted to see if cotrimoxazole would still work even under those circumstances.
And it did, confounding the doubters. 鈥淭here were a lot of sceptics,鈥� says Croxley. Gibb and her colleagues plan to carry on monitoring in Zambia just to make sure that bacterial resistance to cotrimoxazole doesn鈥檛 rise further as more children receive the drug.
The potential of cotrimoxazole came to light in adults with AIDS who contracted a form of pneumonia caused by the fungus Pneumocystis carinii. Later work showed it prevents the same condition in babies born to HIV-positive mothers. The drug turned out to combat fungal diseases, and even some caused by parasites, such as malaria and toxoplasmosis.
鈥淭he antibiotic could be a huge help in regions where anti-retroviral drugs are not yet easily available鈥�
The WHO began recommending cotrimoxazole treatment in 2001, but only if children met certain clinical criteria, such as low counts of the CD4 blood cells that HIV targets. Now the WHO says all HIV-positive children should automatically get it.
Gibb and Croxley stress that cotrimoxazole is no substitute for antiretroviral drugs, which target HIV itself. These achieve a fivefold reduction in death rates.
But because cotrimoxazole is a cheap, safe and effective first line of defence to compensate for a weakened immune system, it could be a huge help in regions where anti-retroviral drugs are not yet easily available, they say. 鈥淚t鈥檚 easy and feasible to supply in resource-poor settings,鈥� Croxley says.
