In 1992, the United Nations adopted its first HIV/AIDS personnel policy. Boutros Boutros-Ghali, then secretary general, said: "I regard this policy as a model for every organization the world over. We regard our personnel as our family."

Meanwhile, Mark Hamilton, who has worked at the UN for a decade, was battling Pneumocystis carinii pneumonia (PCP). At the time, his illness was a secret from his coworkers. Though he'd told a UN doctor in 1990 that he had AIDS, the disclosure was -- he thought -- strictly confidential. "The doctor said he appreciated my honesty and that it would not affect my career," Hamilton recalls.

Two years later, he had another physical, a requirement for contract renewal. Again, he had PCP, but this time the doctor was less understanding: He informed Hamilton that his contract wouldn't be renewed because Hamilton was seropositive.

"No one at the UN knew about the HIV/AIDS policy," Hamilton says. "The UN didn't want to have AIDS. I understand that; I didn't want to have AIDS, either."

Hamilton was furious. "We have to observe the best human rights if we're preaching them," he says. So he threatened the doctor with the disclosure of their conversation to the secretary general's wife, whom he had befriended during his term at the UN Child Care Centre. The doctor signed Hamilton's contract renewal.

Soon after, Hamilton was battling PCP again: "I had to hold on to the wall to walk. I thought to myself, 'Wait a second. This is the UN and I have AIDS, but I can't even tell a soul about it.'"

When he got healthy, Hamilton called a meeting with his coworkers. "I said, 'Look, folks, I have AIDS. I'm not dead. I'm not going to be dead any time soon.'" Everyone was supportive, he recalls, although "one lady cried and had to go home."

He continues to confront his "institution's unwillingness to implement its own AIDS policy." In December 1996, the UN decided to push forward a project proposed by Hamilton to make AIDS medications readily available to UN employees living in countries with little access to such drugs.

"Why only our staff? Well, that's what we can do today. You have to start somewhere," he says.

Four years ago, Hamilton says, his job was "UN dog work." Today, his full-time focus on AIDS has landed him what's probably one of the longest UN titles: "Focal person for HIV/AIDS in the Work-place, UNDP Staff Council and Feder-ation of International Civil Servants' Associations." Perhaps it's easier to simply call him the UN Ambassador on AIDS.