Inexpensive Antibiotic Could Help Millions of African AIDS Patients

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.

“Other drugs that are far cheaper and easier to use than protease inhibitors can have a big effect,” Dr. Kenneth Castro of the U.S. Centers for Disease Control and Prevention told the 13th International AIDS Conference in Durban, South Africa.

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 some 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 for 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 diseases. 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.

But even that is a lot of money in countries where the health budget averages $5 per year per person--which is why Bactrim and other antibiotics are not being used now. For years, it was widely used in developed nations but the advent of effective AIDS suppression has eliminated the need.

Another piece of promising news was presented by Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases. He described new experiments following up on earlier reports that briefly interrupting AIDS drug therapy can be beneficial.

Conventional drug therapy reduces the amount of HIV in a patient’s blood to undetectable levels. Some researchers believe that this intense suppression of the virus allows the immune system to relax its antiviral surveillance.

Researchers such as Dr. Franco Lori of the Research Institute for Genetic and Human Therapy in Washington argue that temporarily halting therapy in so-called structured treatment interruptions allows viral levels to rebound high enough to restimulate the immune system.

Fauci’s new findings seem to support that idea. In one study, which will eventually test 70 people, patients are being given conventional anti-AIDS cocktails for two months and then take a month off.

Fauci said Tuesday that after three complete cycles the immune systems of some patients seemed better able to suppress the virus during the periods of no therapy.

In a second, smaller study, patients are going through cycles of one week on therapy and one week off. Fauci said that the virus never rises above minimal levels during the periods of no therapy, suggesting that the regimen could work for long periods. Some of the patients in the study also show rising levels of CD8 memory T-cells, white blood cells that could help control the HIV infection, he said.

If successful, the therapy would halve the cost of AIDS treatment. And the subjects are pleased, he added. “Patients are absolutely delighted at the prospect of spending half their lives off therapy,” he said.

Several other groups are expected to report similar results this week.

Researchers are particularly looking for inexpensive ways to prevent transmission of HIV during childbirth in developing countries. About 300 children are born HIV-positive in the United States each year, but about 200 per day are born in South Africa alone.

Dr. Glenda Gray of the Chris Hani Baragwanath Hospital in Soweto, South Africa, reported on studies giving the anti-AIDS drugs ddI (Videx) and stavudine (Zerit) to pregnant women for a few weeks before they give birth and to their infants for a few weeks after birth.

Normally, nearly a quarter of the children born to HIV-positive women contract the virus. Gray found that only 1.9% of children born to mothers given ddI and 4.2% born to those given stavudine became HIV-positive. That rate compares favorably to 6.3% for AZT. AZT is the drug most widely used in Africa, but only a small fraction of pregnant women receive it because of the cost.

Some researchers have argued that it does little good to give pregnant women drugs like AZT during childbirth because they will subsequently pass the virus along to children anyway by breast-feeding. But new results from the CDC suggest that the picture is not quite as gloomy as critics thought.

Dr. Stefan Z. Wiktor and his colleagues studied 641 births in Burkina Faso and the Cote d’Ivoire. Half of the women received AZT during the month before they gave birth and half were given a placebo.

At birth, Wiktor reported, 14% of the babies born to mothers receiving AZT were infected, compared with 23% of those born to mothers receiving placebo. After two years, 22% of the babies in the first group were infected, compared with 30% in the second--primarily as a result of breast-feeding.

Clearly, it would be better for infants if mothers did not breast-feed, he said, but “we don’t have to solve that problem to start these regimens” and save some lives.

If HIV-positive mothers must breast-feed, they should not give the children any other forms of nourishment, said Dr. Anna Coutsoudis of the University of Natal. She reported on studies which show that women who breast-feed for the first six months without giving any other liquid or solid foods are significantly less likely to transmit the virus than those who supplement the breast milk, although it’s not clear why.

“Where women are going to breast-feed, there are ways to make it safer,” she said.

Meanwhile, the London-based Panos Institute reported that at least 12 million of the world’s 34 million people currently infected with the AIDS virus need anti-AIDS drugs to suppress the virus. At current prices, that would cost $60 billion a year, representatives of the think tank said at a news conference.

Providing the drugs would be ruinous for most developing nations, said Martin Foreman, director of AIDS programs at Panos. In Zambia, the drugs would cost as much as $2.7 billion--76% of the country’s gross national product. But $60 billion is only a quarter of the U.S. defense budget, he noted.

The institute also pointed out that the cost of some AIDS drugs is higher in developing countries than in the West. Surveys showed, for example, that the average annual cost of the commonly used drug 3TC, also known as lamivudine, ranged from $340 to $810 in Africa, but $290 to $524 in the West.

The cost of a daily dose of zalcitabine (ddC) was 24 cents in Brazil, but $3.75 in the Cote d’Ivoire and $4.17 in Uganda.

The group warned that if pharmaceutical companies do not reduce their prices, many developing countries will ignore the companies’ patents and start producing the drugs themselves.