AS they size up the course of an epidemic that has broken through the walls erected to contain it, AIDS researchers exhibit a mix of concern and expectation.
A decade after the AIDS virus was discovered, few cling to the hope of quick fixes. The prospect of a medical cure seems remote. As researchers probe for a solution, statistics pile up: By the year 2000 the number of AIDS victims worldwide could quadruple to 40 million, according to the World Health Organization (WHO).
Arrayed against this projection is the unprecedented size of the campaign to contain the AIDS epidemic. Though funding is still a major problem, more money and attention have been devoted to AIDS in the past 10 years than most comparable health threats get in a generation.
"We're now into the second decade of an epidemic that is continuing to expand and to cause major human suffering and loss of life," says Helena Gayle, chief of the AIDS division of the United States Agency for International Development. "So it's hard to feel the battle is won."
"On the other hand," Dr. Gayle adds, "we have more knowledge of the virus and there have been advances in learning how to change the behavior that leads to the transmission of AIDS, at least in the short run. We go into the second decade armed with important information and with people who are extremely committed to halting the epidemic." Major AIDS conference
Thousands of doctors and AIDS activists met in Amsterdam last week to weigh the medical, social, and economic aspects of the AIDS crisis. Five thousand scientific papers addressed the unknowns of the AIDS virus. The conference also highlighted two underreported aspects of the AIDS crisis.
The first is that AIDS is becoming more prevalent among women, more of whom are expected to be infected by the year 2000 than men. The second is that AIDS is directly linked to economic underdevelopment and to the low status of women in most developing countries - yet another reason why curbing the AIDS epidemic is likely to be a long-term enterprise.
The meeting was the eighth in a series of annual international AIDS conferences sponsored primarily by WHO. The conference will convene next year in Berlin.
AIDS researchers say some of the biggest successes in the past decade have resulted from aggressive awareness campaigns. Using money donated by developed countries, third world governments are publicizing the risks of aids and marketing condoms as the first line of defense.
"There's definitely a feeling that where we're able to concentrate our efforts we're having an impact," says Michael Helquist, director of the AIDS communication program at the Academy for Educational Development, in Washington. "But we're sobered by the fact that behavior change is much more complex than we had realized."
"Even if you get the point across and people are motivated at first, how do they react six months later?" asks Mr. Helquist, referring to the behavioral changes advocated in AIDS prevention campaigns: use of condoms, and abstinence, or at least a more careful selection of partners.
The origins of the AIDS virus, first discovered in Africa, remain unknown. A decade after its discovery it claims nearly 50,000 lives annually in the US, about the same number who contract the disease each year.
The crisis is far worse in the developing world. As many as 8 million Africans are now HIV positive, a precondition of AIDS, and the epidemic is spreading rapidly in the Caribbean and in South and Central America.
Asia, where AIDS was largely unknown four years ago, is now recording the sharpest increases and could soon have infection rates as high as Africa, the world's hardest-hit region.
Other diseases, including diarrhea and other malnutrition-related illnesses, take a larger toll each year in the developing world. But AIDS has become the focus of attention because it is spreading so fast and has decimated the ranks of the economically most productive age group.
The effects of the epidemic are magnified by the high cost of treatment. Treatment usually means multiple hospitalizations, each involving intensive care, plus high "outpatient" expenses for drugs and services. In the US, treatment costs average over $100,000 per patient annually. Facilities overwhelmed
In poverty-stricken developing nations, where health budgets amount to only a few dollars per capita, such treatment is unavailable. Still, treatment for AIDS patients now overwhelms facilities used to provide vaccinations, improved nutrition, and sanitation. In some of the hardest hit countries, 60 percent to 80 percent of hospital beds are occupied by AIDS patients, says Gayle.
Health officials worry that reallocating small budgets to cope with the AIDS epidemic could undo recent gains in eradicating other diseases like polio and tuberculosis.