Health: Drug doesn't fight the virus but prevents many opportunistic infections. Still, even its low cost poses problems for poor nations.

A widely used antibiotic that costs as little as 9 cents per dose could sharply alleviate suffering among millions of African AIDS patients by preventing pneumonia, toxoplasmosis and many of the other opportunistic infections that characterize full-blown AIDS, researchers said Tuesday. The antibiotic has no impact on the AIDS virus, which is killing 5,500 people a day in Africa, but is simply a means to minimize symptoms. "We are not going to cure HIV with our present drugs, so we need long-term strategies" to alleviate suffering, said Dr. Mauro Schechter of the British Columbia Center for Excellence in HIV/AIDS in Vancouver. Other reports delivered at the world conference indicated that brief interruptions in conventional AIDS therapy can make the drug regimen cheaper and more comfortable for patients and that long-used drugs can help prevent mother-to-child transmission of the AIDS virus. As protests about the high prices of AIDS drugs continued outside the conference center, another new report said that treating patients across the world could cost at least $60 billion a year. The antibiotic in the spotlight Tuesday is trimethoprim-sulphamethoxazole, trade-named Bactrim by Roche or Septra by Glaxo Wellcome. It has been used widely for years in the United States to prevent Pneumocystis carinii pneumonia (PCP), one of the defining infections for AIDS. It is often used treating ear infections in children. In studies in the United States, Dr. Mark Dworkin and his colleagues at the Centers for Disease Control and Prevention found that Bactrim worked against a variety of AIDS-related deseases. He said it reduced the incidence of PCP by 40%, of toxoplasmosis by 30% and of salmonella infections by 60%. It also prevented about 40% of infections by several varieties of haemophilus and streptococcus bacteria. "All those infections are quite common in Africa," he told a news conference. "It's a very cheap drug. In the United States, it's priced at $60 a year," compared with the estimated $15,000 cost of AIDS therapy.