JUDY WOODRUFF: New HIV infections and AIDS-related deaths have fallen so dramatically in recent years that it may be possible to control the epidemic by 2030 and eventually end it altogether.

That's the projection in a new U.N. report released in advance of a major international AIDS conference next week. Officials say those goals can't be met, however, without more prevention or treatment and less discrimination for high-risk groups. Of particular concern, they say, are countries like Uganda, where stigma and HIV rates have both been rising recently.

The MARPI clinic, short for the Most At Risk Populations Initiative, is one of the few public places in the country where gay Ugandans can still come for routine checkups and treatment. Most clinics discontinued these services after the government passed a law in February targeting gays and lesbians with some of the harshest penalties in the world, including up to life in prison.

Stoked by religious leaders and passed by parliament, the law tightened existing restrictions against same-sex activities and banned anything viewed as the promotion of homosexuality.

President Yoweri Museveni signed it after a team of Uganda scientists told him that there is no gene for homosexuality.

PRESIDENT YOWERI MUSEVENI, Uganda: These people are not born like that. They just learn. And they can unlearn what they learned.

JEFFREY BROWN: The move instantly sent some of the nation's most vocal gay activists deep underground. Two of them, Akram and Robert, who asked that their faces be obscured and last names not be used, recently traveled to this safe house in Kampala, the capital.

MAN: I think this bill also wanted to make the activists to become voiceless.

BRANT LUSWATA, Icebreakers Uganda: Yes.

JEFFREY BROWN: They came to talk strategy with Brant Luswata, a health activist with the group Icebreakers Uganda. He runs a clinic that remains open twice a week, but he says most patients became wary about coming when the law took hold.

BRANT LUSWATA: My clients who are living with HIV, I always call them to remember them their appointments. But they don't — the first question they ask, is it safe for me to go there?

JEFFREY BROWN: When a local tabloid published Akram's name and photo recently, marking him of one of what it called Uganda's top homosexuals, he lost his job before the day was over. And his family also made clear their position.

MAN: They throw all my things outside, and they show me the newspaper. “This is — this the proof why we are chasing you away. You should start — you should go and look for your life, start a new life. You no longer belong to us. We are regretting why we gave a birth — we gave a birth to such a child. You are a shame. You are a disgrace to our family.”

JEFFREY BROWN: But he says many of his friends are in even worse shape because, unlike him, they're HIV-positive and afraid they will be outed by their doctors if they seek help or treatment.

MAN: Some of them, they day within their houses. They just perish away like that, most of them, because they fear going to the hospital. Some of them, they use local herbs. Some may get lucky and they heal. Some, they die.

JEFFREY BROWN: Even before the law passed, HIV rates among gay men in Uganda's capital city were already three times higher than other men. Now that divide is expected to grow.

But those who voted for the law, like member of Parliament Dr. Michael Lulume Bayigga, say that gays and lesbians can still receive treatment like anyone else, because patients aren't required to disclose their sexuality.

DR. MICHAEL LULUME BAYIGGA, Ugandan Parliament Member: As a doctor, you may not really recognize somebody on the basis of their sexuality. So that is why they can also access facilities the way they do.

However, I think, when we are now talking about stigma, we are not talking about stigma in terms of other people, external stigma. We are talking about internal stigma, whereby somebody ostracizes themselves.

JEFFREY BROWN: Gay rights activists are incensed by such talk, and point to a large increase in recorded attacks on gays and lesbians in Uganda, from less than 10 for most of 2013 to more than 150 in the months after passage of the law.

And health officials warn the longer-term damages will be more subtle, but very real, resulting from the palpable fear that is driving people away from services they need. It's already happened with Uganda's female sex workers, whose illegal activities make them more vulnerable to attack, bribery and harassment. The infection rate among sex workers is 33 percent, more than four times the general populations.

Asia Russell, director of international policy at the nonprofit Health GAP, says that ostracizing these groups eventually backfires.

ASIA RUSSELL, Director of International Policy, Health Global Access Project: Uganda's rates of new infections are rising. And what evidence has shown is that among the key populations, when you look at sex workers or men who have sex with men, you actually see drastically increased prevalence and increased vulnerability to infection.

That's not because of some abnormality that is akin to those populations. It's because of the impact of homophobia, bigotry, discrimination, and also the marginalization that comes with criminalizing a population. It means people get driven underground.

JEFFREY BROWN: But sex workers in Kampala go still further, saying that some of the responsibility for the stigma they face falls on the United States.

FMR. PRESIDENT GEORGE W. BUSH: This is a historic year for America.

JEFFREY BROWN: In 2003, the Bush administration began requiring nonprofits seeking a share of its massive global AIDS budget to sign a pledge opposing prostitution, saying it is — quote — “inherently harmful and dehumanizing and can lead to trafficking.”

The Obama administration continues to defend the law, though its global AIDS coordinator, Deborah Birx, told the “NewsHour” that: “Comprehensive HIV prevention, treatment and care services for sex workers remain top priorities for the U.S., critical to achieving an AIDS-free generation.”

But many public health groups said being forced to publicly oppose the practice would make their job much more difficult in places where distrust already runs high, places such as Daido Wonders Inn, a brothel in one of Kampala's slums.

Diana Natakunda comes here regularly, usually to work. But, on this day, she's here passing out condoms as a peer educator with WONETHA, an advocacy group for sex workers.

The group's founder and executive director, Daisy Nakato herself a sex worker, has refused to sign the U.S. pledge, saying it further marginalizes these women and makes them skeptical of the motives of those offering crucial health information.

DAISY NAKATO, WONETHA: If one day, WONETHA woke up and signed the pledge, we may not be able to offer services to sex workers. We may not be able to see a big number of sex workers going for HIV screening. We would never be able to see them going for HIV treatment. They will lose trust in us.

JEFFREY BROWN: With the resources it does have, WONETHA focuses on projects that help sex workers gain confidence and stay healthy. They're taught to read, write and speak English using situations relevant to their own lives.

WOMAN: So, you can warn your friend the police will manhandle you. The police is manhandling me, and the police manhandled you or the police manhandled them.

JEFFREY BROWN: When night falls on Daido Wonders Inn, the sex workers say those skills lead to more dialogue with customers, more use of condoms and less violence.

Daisy Nakato believes that not signing the pledge has caused WONETHA millions of dollars over the years.

DAISY NAKATO: Whether all donors put pledges on their funding, I will remain with my value. I will remain fighting the police. I will remain fighting the bad laws. I will remain fighting to make sure that sex workers have access to services, no matter what it takes.

JEFFREY BROWN: Meanwhile on the other side of town, Akram, the once vocal gay activist, says he's just about given up his fight.

MAN: Living in Uganda is living in a hell. This is the worst gay place to be in — in this Uganda.

JEFFREY BROWN: Now Akram and many of his friends are simply looking for a way out. He says that for those who are gay, his country offers few other options.

GWEN IFILL: If you have questions about life in Uganda for the country's gay activists or female sex workers, submit them on our Web site. Our sources from this segment will answer those questions in the days ahead.

You can also see our photo essay on efforts to bring down HIV rates among one of the world's other high-risk populations, drug users along the Kenyan coast. That's all on our Health page.

This segment was produced with the support of the International Center for Journalists.