According to the new report, some 47,000 Americans developed AIDS in 1992 (a 3.5 percent increase over 1991), and more than 40,000 of the new sufferers were males. But the totals tell only half of the story. Between 1991 and 1992, homosexual cases fell by a percent and needleborne cases rose by a percent. By contrast, the number of heterosexual cases soared by 17 percent, and cases involving mother-to-child transmission jumped almost as sharply (13 percent).
If those trends hold a lesson, it’s that AIDS poses a growing threat to women. Owing largely to the increase in heterosexual transmission, the number of female cases shot up by nearly 10 percent last year-four times the 2.5 percent increase that men experienced. Not all women are threatened in equal measure; most of those who contracted the virus sexually are black or Hispanic, and most were infected by men with conventional risk factors, such as IV drug use. Unfortunately, those in the greatest danger are often the least likely to protect themselves. Until that equation changes, the tragedy is sure to expand.
Researchers in Boston thrilled the world last winter when they announced they had discovered “what may be the Achilles’ heel of HIV.” Medical student Yung-Kang Chow and his colleagues at Massachusetts General Hospital reported that a novel combination of three drugs not only disabled the AIDS virus in a test tube but, better yet, kept it from mutating into drug-resistant forms. Doctors have since started testing the new therapy on 400 patients, but independent labs are now flatly contradicting the Boston group’s findings. Last week Dr. Martin Hirsch, the group’s senior scientist, explained why. The findings, he told The New York Times, were flawed.
The experimental treatment combines three medications (AZT, ddI, plus either pyridinone or nevirapine) that are aimed at the same part of the virus. Any one of those agents can hold HIV in check for a while, but as the virus mutates within the patient’s body, the drug gradually loses its effect. Chow reasoned that since every drug-evading mutation makes HIV slightly less efficient, a three-drug combination might cause a mutation overload, leaving the virus paralyzed. His group’s initial experiments seemed to fulfill that prediction: when the team engineered a virus that contained mutations for resistance to all three drugs, it no longer functioned at all.
But when two independent research teams outfitted HIV with the same set of mutations, the virus still grew in cultured cells. And. as Hirsch disclosed last week, the same thing happened when his own team repeated its experiment. In the wake of that revelation, Massachusetts General Hospital issued a statement voicing regret over the “unfortunate error [that] occurred in our laboratory” but noting that Chow’s three-drug combination still “works better in the test tube than several other two-and three-drug regimens.” No one is suggesting that the human trials should stop. But in light of last week’s news, no one should expect any miracles.
