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HIV Drug Resistance Appears Low in Some Developing Countries
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By John Lauerman
Feb. 25 (Bloomberg) -- Health officials monitoring the spread of HIV in Russia, Thailand and Tanzania got positive news from research supported by a World Health Organization effort to fight strains of the virus that can resist drugs.
Studies in selected cities from the three countries found that transmission of resistant HIV probably occurs in less than 5 percent of new infections, researchers said yesterday in Los Angeles. The small studies, each among 50 or fewer people, didn't find any viruses with mutations tied to drug resistance.
Countries with small health budgets depend on cheap drugs, such as generic zidovudine, to combat HIV, which infects about 40 million people worldwide. The Geneva-based WHO, aided by a five-year, $15.2 million grant from the Bill and Melinda Gates Foundation, yesterday said they are helping countries prevent the emergence and spread of resistant strains as a way to preserve the effectiveness of treatments.
``It is serious,'' said Geoffrey Somi, head of surveillance for Tanzania's National AIDS Control Program, in an interview yesterday in Los Angeles. ``Second-line drugs are more expensive than first-line drugs; it would be very bad for the welfare of our patients if resistance were to increase.''
First-line therapies are the initial choice of doctors for treatment because they combine safety, effectiveness and, in lower income countries, minimal cost. Second-line drugs, usually used when patients fail to respond to the first medicines they're given, may have more side effects and higher costs.
One in Five Resistant
In the U.S. and Europe, where drug treatment has been widely available for many years, as many as one in five new infections is caused by a virus with resistance to at least one HIV drug. The WHO is leading a network of researchers trying to stave off the rise of resistance in developing countries.
Tanzania, where about 6.5 percent of the population has HIV, and Thailand are among countries that are rapidly scaling up HIV treatment. Thailand had only 10,000 patients in treatment in 2003. Today, with increased government spending on drugs, there are close to 100,000 in treatment.
The WHO is encouraging countries to step up resistance monitoring as a way to determine whether their growing programs for distributing drugs are effective, said Donald Sutherland, team leader for the agency's HIV-drug-resistance effort. The Spanish government has also given about 1 million euros (US $1.3 million) to monitor resistance in Angola, Namibia, and Senegal.
`Treatment-Program Fears'
``There was a fear before treatment programs scaled up that they might not be well-run, and that resistance might rise higher than we'd like to see,'' Sutherland said yesterday at the conference. ``We said we need the data to see if those fears are justified.''
The Gates Foundation, which has focused its support on development of HIV vaccines and other preventive measures, is providing funding to help the WHO guide anti-resistance efforts in poorer countries where those drugs aren't likely to be available. The contributions from Gates and Spain have allowed the WHO to beef up its monitoring staff in Africa and Asia.
``We all know that drug resistance is the major cause of treatment failure,'' said Nicholas Hellman, director of the Gates Foundation's HIV/AIDS program, at a conference the WHO sponsored to help organize resistance testing. Resistance threatens to ``compromise the economic viability of the scale-up effort,'' he said.
``The problem in Thailand is that the budget has a ceiling,'' said Praphan Phanuphak, director of the Thai Red Cross AIDS Research Center in Bangkok, in an interview.
Thailand
About 600,000 people in Thailand, or 1.2 percent of the population, live with HIV, and the government has allocated about $50 million for treatment and prevention, Phanuphak said. Infection rates are believed to be rising among homosexual men and female sex workers, he said.
Phanuphak received about $20,000 from WHO to test for the spread of drug-resistant strains to young, pregnant women and to homosexual men. Little money is available for efforts like resistance testing, which is why the WHO's support is so important, he said.
``This kind of study would not be funded by the Ministry of Health or any other funding agency,'' he said. ``It's considered a low priority.''
Russian health officials said last week that the country will spend 76.4 billion rubles (US $2.92 billion) to fight HIV, tuberculosis, and other diseases, the TASS government news service reported Feb. 21.
Russian Life Expectancy
The five-year effort is aimed at fighting diseases that keep life expectancy in Russia below levels in high-income nations, the agency reported on its Web site, citing unnamed health ministry officials.
Ten years since doctors found they could cut the emergence of drug resistance by treating patients with drug combinations, the U.S. is also placing a greater emphasis on looking for drug- beating strains of the virus. The U.S. Centers for Disease Control and Prevention now recommends that all newly diagnosed patients receive testing for the presence of drug-resistant viral strains.
Scientists from the National Institutes of Health and the CDC are expected to present results of new efforts to monitor drug resistance at the 14th Conference on Retroviruses and Opportunistic Infections that begins in Los Angeles today.
Drugmakers including Pfizer Inc., Merck & Co., Gilead Sciences Inc., Panacos Pharmaceuticals Inc. and Johnson & Johnson's Tibotec unit are developing new medications to beat resistant HIV strains.
Life-Saving Opportunity
Experts including John Bartlett of Johns Hopkins University School of Medicine have said that new drugs from Pfizer and Merck may create a life-saving opportunity for thousands of U.S. patients who no longer respond to existing drugs because of resistance. In the U.S., those drugs may cost patients about $5,000 a year, said Barbara Ryan, a Deutsche Bank analyst.
To control their HIV epidemics, poorer countries will have to avoid moving to second-line drugs, WHO's Sutherland said.
``South Africa has 5 million people who need to be on HIV treatment that costs about $150 a year,'' he said. ``If it cost $1,000 a year, it would be hard to imagine how it could be sustained. It's crucial to sustain the success we've had for as long as possible.''
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