SÃO PAULO, Brazil — Seeking to stem a sharp rise in H.I.V. cases among young people, Brazil began offering a drug this month that can prevent infection to those deemed at high risk of contagion.

Brazil is the first country in Latin America, and among the first in the developing world, to adopt the drug, known as PrEP, short for pre-exposure prophylaxis, as an integral part of its preventive health care policy. The blue pill — which drastically reduces the risk of contracting the virus when taken daily — will be made available at no cost to eligible Brazilians at 35 public health clinics in 22 cities during an inaugural phase of the program.

The Brazilian Health Ministry is paying Gilead Sciences, the American manufacturer of the drug, about 75 cents a dose, a fraction of the price users pay in the United States, where PrEP sells for upward of $1,600 for a month’s supply.

The drug is being rolled out at a crucial time in Brazil, with the country’s health officials particularly alarmed by the rise of the virus among young men and other groups considered at higher risk.

Between 2006 and 2015, the number of AIDS cases in men aged 15-19 almost tripled, to 6.9 cases per 100,000 people. Among men 20-24, the rate almost doubled to 33.1 cases per 100,000, according to U.N.AIDS, a United Nations agency that coordinates H.I.V. prevention policy around the world.

Approximately 48,000 new cases of H.I.V. were reported in Brazil in 2016 and about 14,000 deaths related to AIDS, the agency said. While the transmission of the virus from mother to child has been significantly reduced, about one in 10 men who have sex with men in Brazil have H.I.V., the agency said.

“Our hope is that with PrEP and other measures we can reduce the rate of new infections,” said Adele Benzaken, the director of the AIDS department at Brazil’s Health Ministry. “But it’s a big challenge.”

PrEP is being made available to prostitutes, transgender people, men who have sex with men, some drug users and people in relationships with partners who have H.I.V. Read more via New York Times