AIDS mutates to defy drugs

Baltimore reports progress on TB, syphilis, gonorrhea

April 04, 2001|By Jonathan Bor | Jonathan Bor,SUN STAFF

Years of progress against the AIDS epidemic is being threatened by viral strains that resist the drugs designed to defeat them, Baltimore's top health official warned yesterday.

Dr. Peter L. Beilenson said the problem has been fueled by patients who begin drug therapy but fail to adhere to complicated dosing schedules. Spotty compliance allows the virus to mutate into forms that can be untreatable.

Citing a recent national study, he said 14 percent of new AIDS cases across the United States are resistant to two or more drugs. But he said that the rate is probably higher than that in Baltimore, where the epidemic is largely one of intravenous drug users -- a population that is notoriously hard to monitor.

"For people infected with those strains, we're going back 20 years to when the disease was universally fatal," Beilenson said.

His statements came during an annual briefing on city health trends, in which he said stronger public health efforts have brought progress in many areas. In most cases, the latest statistics were gathered in 1999.

That year, tuberculosis cases declined to an all-time low. The city also dropped from first in syphilis cases to third nationwide, continuing a decline that began in 1997. Baltimore still has the nation's highest gonorrhea rate, but that problem has abated as well, he said.

Meanwhile, the number of drug addicts in treatment doubled over the past four years. Over 99 percent of school-age children were immunized against major diseases, possibly the best rate of any urban center in the United States, Beilenson said.

Also, the number of newly diagnosed AIDS cases declined from 783 cases in 1998 to 585 cases in 1999 -- the lowest number since cases peaked in 1993.

Beilenson said much of the progress against AIDS was due to the success of new drug regimens, which extend the time it takes for a relatively low-grade infection to worsen and produce symptoms of full-blown AIDS.

The drugs, which became standard treatment in the mid-1990s, have enabled many people to live and work for many years past their diagnosis. Earlier, it had been rare for AIDS patients to live more than a few years with the disease.

To benefit, however, patients have to take several drugs at intervals throughout the day. Drug companies have begun to make the schedules simpler, but patients still cannot afford to miss many doses.

Strains could be untreatable

If they miss their medications, patients who harbor a treatable strain can see their disease turn resistant. They can also infect someone else with the new strain, making it difficult to impossible for that person to find effective treatment.

"This is a very real concern," said Dr. Robert Redfield, director of AIDS clinical services at the University of Maryland Medical Center. "The consequence is that the epidemic could become untreatable -- disproportionately in poor populations."

Redfield said this could create a disturbing biological disparity across the city: untreatable strains among the urban poor, treatable strains elsewhere.

Several years ago, doctors were optimistic that they could defeat the resistance problem by changing the drugs -- or drug combinations -- patients are given.

"The optimism that we'd be able to keep doing that has not borne out," Redfield said. One major problem is that strains that are resistant to one drug are also resistant to other drugs that work in the same way.

The number of people dying from AIDS has not risen, Beilenson said, though he said that could soon change.

Patient supervision needed

For many patients, he said, the problem isn't simply remembering to take each dose. Many patients also skip doses because they are experiencing unpleasant side effects.

Beilenson said he might fight the problem by bringing therapies to the patients -- a strategy borrowed from the city's successful program of TB control.

For decades, public health nurses have personally delivered TB medications to patients and watched them take every pill. This method helped Baltimore prevent the outbreaks of drug-resistant tuberculosis that afflicted many cities in the past decade.

Because the number of AIDS patients is much higher, it would be impractical to make home visits, he said. But the city might be able to deliver the drugs from vans stationed at locations throughout the day. Patients could be provided inexpensive alarm watches to remind them of the time, he said.

The health commissioner said he is also concerned about the spreading epidemic of hepatitis C, a potentially fatal liver infection, among intravenous drug users. A recent study showed that well over 90 percent of the city's addicts harbor the virus.

The disease is a leading cause of liver failure, and the No. 1 reason for liver transplants in the United States. Baltimore has an estimated 40,000 addicts who inject their drugs. Some 36,000 of them are infected with hepatitis C, he said.

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