GENEVA -- On a large map of the world on the sixth floor of the World Health Organization's headquarters here, colored pins mark a shifting battlefront in the international war against AIDS.

Each pin records how far a country has gone in examining its national AIDS problem and, with the help of visiting teams of WHO experts, formulating a plan to control the disease.

On the day of a recent visit, yellow pins, signaling a request for a visit, were clustered in Asia and the Pacific islands. Blue pins, meaning an initial visit had been done, were scattered throughout the world. Green pins, signifying countries that had developed a plan of action for the next year, showed up frequently in Africa and in Central and South America. Red pins, symbolizing a longer-range strategy for fighting the epidemic, were the rarest, appearing only in a handful of countries, most of them in Africa.

There is no pin marking the United States, noted Dr. Jonathan Mann, director of WHO's Special Program on AIDS, during a recent interview here. Asked why, Mann shot back, "Does the United States have a plan for AIDS control?"

The perennially out-of-date map, which members of Mann's staff update with additional pins whenever they get a moment between trips and meetings, is one measure of how far the organization's AIDS program has come since its inception last February. "We set a goal nobody said we could meet," Mann recalled -- a goal of visiting 50 countries by the end of 1987.

The program has far outstripped that goal. By the beginning of November, health teams had already visited 77 countries. Sixty-four had developed short-term plans to cope with the epidemic, and 27 countries had a five-year plan, according to Mann's assistant, Kathleen Kay. Uphill Battle

The rapid growth of WHO's AIDS program is chiefly due to the determination of Mann, a former Centers for Disease Control epidemiologist who arrived in Geneva just over a year ago. Starting with a secretary, a $500,000 budget and a position that left him perched at the end of a long branch of the WHO bureaucracy, Mann has built the program into one of the agency's largest and most active, with a $37 million budget for 1987. He now reports directly to WHO director general Dr. Halfdan T. Mahler.

Even so, Mann and his staff acknowledge they are fighting an uphill battle against the burgeoning international epidemic, which is the greatest challenge WHO has faced in its 39-year history.

"Smallpox {eradication} was a major crisis, but nothing comparable to this," said Dr. Manuel Carballo, who coordinates WHO-sponsored behavioral and social research on AIDS.

"If we can clone Jonathan, if we can get a dozen Jonathan Manns, we might survive this year," added Dr. James Chin, a statistics specialist from California in charge of forecasting the epidemic.

Helping countries develop their own AIDS-control efforts and acting as a middleman in the international funding of such efforts is the WHO program's primary purpose. Other activities include planning and sponsoring AIDS-related research, such as studies of sexual behavior in various cultures, and organizing technical conferences on such topics as AIDS and breast-feeding or AIDS and international travel.

The WHO program's central message, reiterated by Mann in every speech and interview, is that AIDS is a scourge that can only be fought by an international cooperative effort, not by searching for scapegoats or refusing to share technology, money and therapies.

"When a vaccine becomes available," Mann said, sighing and crossing his fingers, "WHO is going to make sure that it's available to the whole world and not just to the rich. Will we succeed? I don't know. We are saying loud and clear that this is a matter of fundamental justice . . . {but} I can't tell you how we're going to do it yet."

Coordination Efforts

For now, Mann's energies are focused on expanding and strengthening the international AIDS network. On the day of a recent interview, he said, he started the morning with a meeting with the secretary of the Bulgarian government's AIDS committee. Then he talked with two public relations experts about developing a media campaign to explain the WHO's AIDS program.

After an hour-long Washington Post interview, he planned to see representatives of an international organization for the control of tuberculosis and lung diseases. "Tuberculosis control in the developing world is very related to AIDS control and vice versa," he explained. TB rates have skyrocketed in countries with high rates of infection with the AIDS virus, because the virus's damage to the immune system makes infected individuals more vulnerable to the bacterium that causes tuberculosis. And public health workers already trained in TB control efforts are logical recruits in the battle against AIDS.

At noon, he had an appointment with a consultant hired by the agency to help set guidelines for developing countries trying to establish systems to screen blood donors for the AIDS virus. Next, he would meet with staff members to prepare for a mid-November conference of international donor organizations and representatives of countries seeking outside funding for their AIDS-control efforts.

The WHO program uses such conferences to coordinate international funding so that control measures will not be delayed while a country waits for assistance. "This is a very important meeting for us," said Mann. "Coordination is the easiest word to trip off the tongue, and it's the hardest thing to do."

During the afternoon, Mann had scheduled a series of meetings with staff members who were developing methods for comparing AIDS infection rates in different countries, compiling the WHO program's first annual report and planning an upcoming conference on AIDS and prisons. Between appointments, he said, he expected to field 15 to 20 telephone calls and work on four or five articles and speeches.

Mann, who spends half his time traveling, said he has become adept at dictating while he waits in international airports. "I've gotten to the point where it's really irritating to me to be in an airport where they announce everything in three or four languages," forcing him to turn off his tape recorder during each announcement, he said.

He is a slender, fast-talking, enthusiastic administrator whose willingness to bite off more than he can chew is a source of both amusement and consternation to his staff.

"If something is in the way, Jon says, 'Don't go around it, go through it,' " said Chin. "I'm not sure he can survive these 16-hour days {but} so far he seems to be thriving on it."

Mann admitted that the major disadvantages of the job are fatigue and not having enough time to spend with his wife and three children. "I can't look beyond a few years," he said. "I had the privilege of being here at the genesis" of the AIDS program. "Certainly it's the most challenging, most exciting and most demanding position I have ever been in."

He said that during medical school he planned to become an ophthalmologist, but when his wife became pregnant with twins and had to stop working, he got a federal scholarship to finish his studies. In exchange, he had to serve two years in the Public Health Service, so he took a job with the Centers for Disease Control and was assigned a post in the New Mexico health department.

He stayed in New Mexico for 10 years, becoming the state epidemiologist. Then, in 1984, wanting a change, he rejoined the CDC and went to Zaire to establish and direct Projet SIDA, an AIDS research project involving Zairian, Belgian and American collaboration. His success in that program put Mann in the forefront of fledgling efforts to confront the international epidemic and led to his recruitment by WHO last year.

Keeping Count

Besides responding to countries' requests for funding and technical assistance, the WHO program is responsible for tallying worldwide AIDS cases and forecasting the global impact of the epidemic. Chin, who retired from the California state health department last March to take charge of WHO's AIDS surveillance, said he is developing a standard method for carrying out blood testing to determine the frequency of infection with the virus in large populations.

Such large-scale surveys are urgently needed in some African countries where as many as 15 percent of blood donors and 25 percent of pregnant women in large cities are infected. He said the first such national survey will probably be done in Uganda.

Chin said the WHO is also supporting development of better mathematical models for forecasting the epidemic but added that such work is hampered by the many unanswered questions regarding the natural history of infection with the AIDS virus, such as whether an infected person is always capable of transmitting the virus and what proportion of infected individuals will eventually develop the disease.

The WHO estimates that between 5 million and 10 million people are infected worldwide, but Chin said such estimates are only a rough guess. "A million here, a million there," he said. "All we know is, we're talking, at least in terms of infected people, in millions."

Equally uncertain is how rapidly the virus may spread in different countries through sexual transmission, drug abuse or the use of unsterilized needles. The WHO AIDS program is beginning to collaborate with research groups in about 15 countries to develop questionnaires and methods for obtaining reliable information on sexual practices, according to Dr. Manuel Carballo, coordinator of behavioral and social research.

"Most people working in the area of AIDS control and prevention strategy have realized early on that they are really working in the dark," said Carballo. "There is no reason to believe that sexual behavior follows the same patterns in all societies, in all cultures and in all age groups."

Carballo said the program will also sponsor research on the frequency of intravenous drug abuse, tattooing and decorative scarring -- practices that can spread the disease through the sharing of unsterilized needles -- and the use of "injectors," individuals who lack formal medical training but make a living by injecting patients with folk remedies.

Carballo said there are "hundreds of thousands" of such injectors practicing in countries around the world. "We need to know who they are, where they work, whom they cater to, what they understand about sterilization and {AIDS} transmission," he said.

Carballo said research is also planned to identify potential roles for traditional healers, local leaders and others -- perhaps, he suggested, even prostitutes -- as AIDS educators. He predicted that the epidemic, while exposing the limitations of formal health and social welfare systems, may also bring out "a richness of society -- that there are people willing and able to do things that they, otherwise, have never been called on to do."

The time required for such long-term research contrasts sharply with the tight schedules required to respond to countries' urgent requests for teams of experts and financial assistance. But Mann and his staff believe both efforts are needed to counter the threat posed by AIDS.

"AIDS is the archetypal communicable disease," said Carballo. "We're all at risk."