AIDS: casual contact exonerated.

Research findings on AIDs at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Minneapolis this week covered the gamut from good to bad to surprising. The good news: The syndrome is apparently not transmitted through casual household contact and hence not among school children; health care workers who handle AIDS patients, even workers who have accidentially stuck themselves with needles, have little if any chance of becoming infected, according to researchers.

The bad news: Heterosexual transmission, at least in Haiti and Africa, is becoming increasingly prevalent. And the surprising news: The virus associated with the disease may have bee around as long ago as 1962.

A Centers for Disease Control (CDC) study of 101 members of households that included an AIDS sufferer shows transfer of infection only in one instance, in a baby born to an infected mother. "From this study," says Martha F. Rogers of the CDC in Atlanta, who headed the study, "our best estimate of the risk of household transmission is zero." The belief that AIDS victims in schools can transmit the disease, she says, has not scientific basis in the data collected thus far.

Three studies presented at the meeting show little if any risk to health care workers involved with AIDS patients. In a CDC study of 802 workers nationwide who had been exposed to AIDS blood or body fluids, only one person with no other risk factors was infected with the virus; of 527 health care workers in two prospective studies, only 1 of 95 workers who had accidentally stuck themselves with a needle, showed evidence of exposure. The incidence might be slo low because it takes repeated exposures or an overworked immune system to allow the virus to establish itself, researchers suggested.

Heterosexual transmission is establishing itself as a mode of infection in Haiti and Africa. In Haiti, 14 percent of AIDS victims in a 1980-1982 survey were women; thus far in 1985, 36 percent are women, reports Warren D. Johnson Jr., of Cornell Medical College in New York City. When the researchers questioned AIDS patients about recent deaths of spouses, they found 5 percent had spouses who died of confirmed AIDS and another 15 percent had died of what seemed to be AIDS.

A study in Kenya, which has not reported a high AIDS incidence, shows the virus is establishing itself among prositutes at an alarming rate. Of 64 women who served a "lower class" clientele, 42 had AIDS antibodies, while 8 of 26 with a "highter class" clientele had antibodies; no overt disease has yet been seen.

Where the virus comes from remains to be solved, but a report at the meeting may add 10 years to its age. J.A. Epstein and colleagues at the Food and Drug Administration reported finding AIDS-specific antibodies in two of 544 blood samples collected in Upper Volta in 1963--10 years earlier than previously reported Ugandan samples (SN: 3/16/85, p. 173). Whether this means the AIDS virus itself was present, or just a similar virus, remains to be seen, Epstein says.