Public health officials attending an international conference here warned that a study of African AIDS victims suggesting that members of the same household are more likely to become infected with the deadly virus than members of other households should be interpreted with care.
Dr. Jonathan Mann, a scientist with the federal Centers for Disease Control (CDC), described the results of a federally sponsored study of acquired immune deficiency syndrome (AIDS) patients in Zaire that indicated that the virus could be spread by nonsexual means among members of their families. But he added, "We must use great caution in interpreting these findings."
Dr. Mervyn Silverman, San Francisco's former commissioner of public health, agreed. "It is inappropriate to extrapolate simply from Zaire to the United States," he said. "A household in Zaire is not the same as a household in the U.S."
Mann presented his findings, which had been disclosed unofficially last week, at an international meeting on AIDS. More than 2,000 physicians and scientists have come to discuss the deadly virus, which has afflicted at least 9,000 victims in the United States alone.
Mann and Zairean doctors found that family members living in the same household with AIDS patients in Kinshasa, Zaire, were three-times more likely to show signs of infection by the AIDS virus than household members of persons who were ill with other diseases. Mann said that this might be explained by "the microtransfusions inherent in family life. These findings may show that infection with the AIDS virus can be transmitted by intimate and prolonged, but nonsexual, contacts."
But he pointed out that the result also could indicate that persons living in the same household were exposed to a common source of the AIDS virus. For instance, family members might be more likely to practice rituals in which persons cut themselves, which might lead to the spread of AIDS by way of contaminated blood.
Silverman said the evidence arguing against the ability of AIDS to spread through U.S. households is "overwhelming."
Dr. James Oleske, of Newark, today presented his findings after studying cases in which infants in New Jersey became infected with the virus. None of their 14 siblings or 10 foster mothers showed signs of AIDS infection during two years of living with the affected infants, Oleske found.
At the same meeting, Dr. James Curran, head of the CDC task force on AIDS, suggested that, if a vaccine becomes available that can fight the AIDS virus, "It would probably be necessary to vaccinate all Americans."
Such a strategy would result in the "rapid reduction in incidents of new infections, but perhaps only a gradual leveling-off in AIDS, because of the large pool of persons already infected."
"So far, we have talked mostly about how to make a vaccine," he said in an interview. "I wanted to push people to think about how we would use a vaccine if we had one. Use of a vaccine would require quite a massive endeavor. I think it would be worth it. But I wanted to point out that if scientists gave us a vaccine tomorrow, it would not be a magic blessing."
One potential problem that has been raised is whether the vaccine could cause the AIDS virus to alter its properties so that the vaccine would no longer be effective. Scientists said that this is theoretically possible but that it is too early to know whether it would happen.