The number of adolescent deaths from AIDS has tripled in the last 15 years despite efforts to curb infections, with the majority of cases reported in sub-Sahara Africa, the United Nations Children’s Fund announced Friday.

The UNICEF study found that 26 adolescents are infected every hour, and only one in 10 adolescents in sub-Saharan Africa is tested for HIV.

Girls in the region are disproportionately affected, accounting for 7 of 10 new infections among 15-19 year-olds, the study found.

Many teens who die of AIDS were infected as infants

“It is critical that young people who are HIV-positive have access to treatment, care and support,” Craig McClure, head of UNICEF’s global HIV/AIDS programs, said at a conference in Johannesburg, South Africa, where the report was released.

“At the same time, those who are HIV-negative must have access to the knowledge and means to help them to stay that way,” McClure said.

Adolescents with the HIV virus are the only infected group for which mortality figures are not decreasing, UNICEF said. Nearly 2 million adolescents between the ages of 15 and 19 are living with AIDS, UNICEF said.

Many adolescents who die of AIDS-related illnesses were infected with HIV as infants, at a time when fewer pregnant women and mothers carrying the virus received antiretroviral medications to prevent transmission, the study said. Some of those children have survived into their teens, sometimes without knowing their HIV status, UNICEF said.

“The gains we have made on preventing mother-to-child transmission are laudable and to be celebrated,” McClure said. “Immediate investments are needed to get lifesaving treatment to children and adolescents who are infected.”

AIDS is number one killer of adolescents in Africa

The report shows that about half of the adolescents with HIV live in just six countries: South Africa, Nigeria, Kenya, India, Mozambique and Tanzania.

Infections also continue to occur in Uganda, where Pope Francis is spending the weekend — and it is a country in which nearly 1.5 million people are living with HIV, according to the latest UN data.

Preventing HIV transmission and addressing the challenges of living with AIDS are some of the topics Francis is expected to discuss Saturday with young people in Kampala, the capital of Uganda, on the second leg of his trip to Africa.

AIDS is the number one cause of death among adolescents in Africa and the second leading cause of death among adolescents globally, according to UNICEF.