DAR ES SALAAM, Tanzania — East African nations have launched some of the world’s most vicious campaigns against gay men and women, outlawing homosexual behavior and threatening to punish it with years in jail.

But in a move that has alarmed health workers, Tanzania is turning its anti-homosexual fury in a new direction — targeting HIV/​AIDS programs that have helped tame a disease that once ravaged the region.

Last month, the minister of health announced that Tanzania will ban HIV/​AIDS outreach projects aimed at gay men, pending a review. That forced the closure, at least temporarily, of U.S.-funded programs that provide testing, condoms, and medical care to homosexuals. About 30 percent of gay men in Tanzania are HIV-positive; now health workers say that figure could rise.

Tanzania’s actions appear to mark the first time that a country has suspended parts of the United States’ hugely successful foreign HIV/​AIDS initiative in an attempt to crack down on the gay community. The U.S. PEPFAR campaign, backed by $65 billion since it was founded in 2003, has been credited with saving millions of lives.

The ban comes after months of bitter speeches and threats from Tanzanian officials aimed at the gay community and at organizations treating its HIV/​AIDS patients. This year, police raided two U.S.-funded HIV/​AIDS organizations and seized confidential patient information and supplies, officials said. In September, the deputy minister of health, Hamisi Kigwangalla, accused HIV-treatment organizations of “promoting homosexuality.”

“Any attempt to commit unnatural offenses is illegal and severely punished by law,” Mr. Kigwangalla said in the statement. People convicted of gay sex in Tanzania can be jailed for up to 30 years.

The health minister, Ummy Mwalimu, explained in a statement last month that officials had suspended HIV/​AIDS outreach programs for gay patients to review whether they promoted same-sex relationships.

The move has sent a shock wave through a community still grappling with the virus, even as modern medicine and treatment have dramatically improved victims’ chances of survival.

“In the short term, there are people who won’t go to [health] service centers, and if they aren’t on antiretrovirals, what happens? It’s a major concern,” said Warren Naamara, a doctor who is the country director of the U.N. program on HIV/​AIDS in Tanzania, referring to the drugs that suppress the virus.

PEPFAR, or the President’s Emergency Plan for AIDS Relief, launched by George W. Bush with bipartisan support, has become one of the most important U.S. assistance programs ever in Africa. Tanzania is an example of its success. Since 2002, the overall HIV/​AIDS rate in the country has declined from 12 percent to 5 percent. The number of people receiving treatment has grown in the past five years from 289,000 to over 700,000.

But even as assistance programs have sharply reduced the death toll from AIDS, some countries in East Africa have been escalating their campaigns against homosexuality.

In 2014, Uganda’s parliament passed a law, later annulled, that imposed the death penalty on those found guilty of “aggravated homosexuality.” This year, a Kenyan high court ruled that “anal tests” aimed at determining people’s sexual orientation were legal.

Even though Tanzania’s penal code refers to homosexuality as a “gross indecency,” the government had long permitted organizations to help gay men who had AIDS or who were at risk of contracting it.

But since President John Magufuli was elected last year, the government’s tolerance on the issue has disintegrated. Although Mr. Magufuli has not said anything publicly about homosexuality, a number of his appointees have made harsh remarks.

Hope for restoration

The U.S. government has hired health organizations such as Jhpiego, which is affiliated with Johns Hopkins University, to provide HIV tests, condoms, and doctor referrals for gay men, sex workers, and other vulnerable Tanzanians who are afraid to visit a public hospital. Those visits often take place in homes and informal community centers. The Jhpiego project was awarded $73 million over five years beginning in 2015. But such groups have had to cease their outreach efforts in gay communities.

U.S. officials said they are hopeful that the outreach programs will soon be restored, noting that the health minister has said the government is considering which HIV services would be appropriate for the gay community. But members of that community are pessimistic.

“It’s clear that the government doesn’t care whether we live or die,” said one 22-year-old gay man, who spoke on the condition of anonymity because of fear of punishment.

Each week a patient is off his antiretroviral drugs, the virus grows more crippling — what doctors call a “viral rebound.”

“These interruptions in treatment are very dangerous,” said Dr. Naamara of the U.N. program, known as UNAIDS.

“Homophobic rhetoric from government officials will only drive already vulnerable populations underground,” said Boris Dittrich, the advocacy director of Human Rights Watch’s LGBT division.

Homosexuality is criminalized in at least 76 countries, and at least 33 are in Africa, according to the United Nations’ Free and Equal campaign.

First Published November 27, 2016, 5:00 a.m.