THE LATEST DISCOURAGING REPORT about AIDS treatment came last week with the publication in the British journal Lancet of a major Anglo-French study on the drug AZT The so-called Concorde trial (whose preliminary results were announced a year ago) followed 1,749 people who were HIV-positive but had no symptoms of illness. After a year, subjects on AZT were doing better than those who got a placebo, but after three years, there was no benefit from the drug: 18 percent of both groups had developed AIDS symptoms. And in terms of mortality, those on AZT fared slightly worse; 8 percent had died, compared with 6 percent of the placebo group. The study will continue for another 15 months.
While AZT can delay the worst ravages of AIDS in those already sick, it also has serious side effects, including nausea, vomiting and anemia. For HIV-positive people without symptoms, says Ian Weller, the senior British member of the Concorde team, taking the drug is not worth those risks.
Some other medical news last week:
It's no secret that cigarettes contain hundreds of chemical additives. Under a 1984 law manufacturers have to submit lists of ingredients to the federal government, but federal officials are strictly barred from making the lists public. Last week National Public Radio obtained the names of several common additives, and they don't sound appetizing. According to NPR, the current list of 700 additives includes at least 13 chemicals that are barred from food and five that have been designated as hazardous substances.
In addition to irritants like ammonia, the roster includes Ethyl 2-furoate (which causes liver damage in animals and was once studied as a chemical warfare agent), Sclareol (which can trigger convulsions when combined with other chemicals and Methoprene (a pesticide used on stored tobacco). A tobacco-industry toxicologist insists the additives are all safe at the levels present in cigarettes, but some in Congress are skeptical. At the very least, say health advocates, smokers should know what they're consuming. To that end, the House of Representatives will hold hearings this week on ending the government's policy of secrecy.
Two new reports suggest that house cats are transmitting bubonic plague and other diseases to people. Plague, a bacteria] illness that can kill unless promptly treated with antibiotics, typically spreads via rodents and fleas. But since 1977, re searchers at the U.S. Centers for Disease Control and Prevention (CDC) have linked 15 human cases to domestic cats -and they say cats caused at least two of the 10 cases recorded in the United States last year. CDC researchers blame the trend on suburban development, which places pets near to the mice, squirrels and prairie dogs that carry the plague bacteria.
Plague isn't the only cause for concern. In a separate study, published in the journal Lancet, an Austrian researcher concludes that domestic cats may also be spreading several rodent-borne viruses, in eluding hantaviruses, notorious in Europe and Asia for causing hemorrhagic fevers and kidney failure. No one yet knows whether cats can transmit the lung-killing hantavirus that has spread from New Mexico to New York in the past year, striking more than 50 people. But since it is roughly 50 percent fatal, it's a chilling possibility.
While far fewer U.S. women die annually from ovarian cancer (13,600) than from cancer of the lung (59,000) or breast (46,000), the disease is particularly terrifying because it's so seldom diagnosed at an early, curable stage. And last week a National Institutes of Health panel concluded that current screening methods don't seem to do much good. Routine screening with a blood test called CA 125 and an internal pelvic sonogram, said the panel, often lead to false alarms and unnecessary, even risky, surgery. In one recent U.S. study, 65 exploratory surgeries were performed for every ovarian cancer found.
The panel called for clinical trials to evaluate existing screening methods and identify better ones. In the meantime, women should be reassured that the overall risk of ovarian cancer is low. For most, the lifetime risk is 1.5 percent-and even for those with an afflicted mother or sister, it's only 5 percent.