(CNN) For 22-year-old Sabelo Chonco, his years as a teenager weren't quite the same as those of the people around him.

While his best friends were asking out girls and talking about them endlessly, he dreaded the thought.

He feared that they would find out the secret that had weighed heavily on him for years.

"It wasn't easy, because people started dating in 10th grade, and I was scared," Chonco said, recalling his time as an otherwise sociable teenager in the South African state of KwaZulu-Natal. "All my friends had girlfriends, but I was scared to have it."

At 16, the reason for Chonco's concern wasn't the usual angst and awkwardness but the fact that he is HIV-positive -- and has been since birth.

"The strategy I was using was to pretend like I know everything and have been in a relationship," he said.

Unlike many infected with HIV, Chonco had never had sex. He only discovered that he was HIV-positive at the age of 14.

Sabelo Chonco was born with HIV but only found out at the age of 14.

"I was very sick until they put me in hospital," he recalled, about what may have been the early stages of AIDS, as he was not then receiving treatment. "Then they told me I have HIV."

He speaks softly as he remembers, contemplating the situation he faced at such a young age. Chonco's mother died in 2004. He suspects the cause was AIDS but cannot confirm it because she never disclosed her status to her family.

"She died and never told anyone," he said. He believes that she must have known his status, as he was in and out of hospital as a child when she was still alive. He thinks she must have been afraid to tell him the truth.

"I know that I got it from my mum, because there's no other way I would have got it at that time," he said. "I was too young."

And then there he was, 16 years old, surrounded by friends who were having relationships -- and, more worryingly, sex.

At this age, Chonco was still processing the discovery that his mother probably had HIV and that he had contracted it from her during her pregnancy.

He lied about his experiences out of fear of infecting others but also because he feared being judged. "In our area, some people are still scared," he said of the stigma surrounding HIV, despite how prevalent the infection is: In KwaZulu-Natal, almost 40% of adults are HIV-positive. "At the start, it was hard."

Now, he has had a stable relationship but remains guarded about who he lets into his heart, as it comes with an incredible level of trust. "You need to tell your girlfriend how you are, because you can't get her infected," he said.

His ideal, he explained, is to one day fall in love with someone who is also HIV-positive, so they can share the experience together, without stigma, and even have children if they both adhere to their treatment. Continuous treatment can make virus levels undetectable in the blood.

But one step at a time, he warns. "I want to achieve things first."

Falling numbers born with HIV

Cases like Chonco's are less common and are likely to decrease even further in the coming years due to the success of prevention of mother-to-child transmission programs, known as PMTCT, now routine throughout the world.

These programs involve screening all pregnant women for HIV, providing immediate treatment with antiretrovirals if necessary and, if needed, providing a short course of treatment for their babies to prevent them from developing the infection. The treatment can reduce the likelihood of transmission from as much as 45% to 5%.

More than 95% of pregnant women in South Africa were estimated to receive PMTCT in 2015, according to UNAIDS , which translates to more than 250,000 women. That means fewer young people will have to face scenarios like Chonco's.

But today, rare groups of individuals who were born with HIV have a unique set of problems and challenges -- social and psychological -- that are themselves evolving constantly.

"The challenges (teenagers) face now are different to mine," Chonco said. "Nowadays, they want to leave treatment. I think peer pressure is there because friends may not be taking it."

The challenge of adherence is present for all ages infected with HIV, but for people born with the infection, years of taking pills can leave them wanting to rebel during adolescence.

"For some, taking pills their whole lives just becomes too much in their adolescent years, and they have a real sense of wanting to take a break," said Linda-Gail Bekker, president of the International AIDS Society. Bekker works with teens on the other side of the country, in Cape Town, but sees the same challenges.

"For others, the difficulty is the transition from a very nurturing pediatric service environment to a much more independent (and therefore intimidating) adult service."

Making it through the teen years

Chonco has two siblings, neither of whom is HIV-positive. They remain the people he trusts most with his secret. Even today, very few of his friends know his status, if any.

But there is one other group of people -- teenagers, mostly -- with whom he is willing to readily disclose his HIV status. It's a group that shares the same problem, with many finding out that they were infected in a similar manner.

They're the attendees of a teen HIV clinic based at Don McKenzie Hospital in Durban, South Africa, where services have been made "adolescent-friendly" to ensure that people have others to bond with -- and that they stay on their treatment. There's even a summer camp to educate and empower them on the issues they face while allowing them to just be teenagers together.

Attendees learn about "life, education, careers and self-esteem," Chonco said.

In general, people who are HIV-positive collect their medication every one or two months and must take it daily. Many teens involved in the camp described that they routinely take their pills in the evening, but the routine becomes challenging when they start going out at night and want to take them without being noticed.

"In adolescence, it's important to be just like everyone else, and at school, when you have HIV, you feel like you're not just like everybody else," said Dr. Brian Zanoni, an infectious disease specialist at Massachusetts General Hospital in the United States who set up the clinic in Durban in 2009.

He established the clinic to give teens a place to go that would show them there were others like them but also, more important, to help them answer the big questions that they have no one to ask about. How do I tell my girlfriend or boyfriend? How do I take my antiretrovirals if I'm out on a date? Can I have safely have a baby one day?

"When you're in a clinic where you know everyone else is infected with HIV, taking the same medicine and dealing with the same problems you are, then it becomes a place you look forward to coming to," said Zanoni.

From a clinical perspective, for Zanoni, if teens are eager to attend their clinics, they're more likely to collect and take their meds, meaning the levels of the virus they carry will be suppressed. A landmark study in 2011 found that someone taking antiretrovirals consistently reduces their chances of spreading HIV to others by as much as 96%.

In 2015, it was estimated that 790,000 young people ages 15 to 24 were living with HIV in South Africa. The country as a whole has among the highest rates of HIV in the world, with 7 million people estimated to be living with the infection in 2015 and 380,000 new infections that year.

For Zanoni, his clinic was a place to ensure that teens became fit and healthy in the face of these numbers.

"That's generally the goal of therapy," he said. "To suppress the virus to undetectable levels so the immune system can wake up and they stay strong and healthy and normal teenagers, essentially."

Embracing teen angst

The benefits for teens of Zanoni's clinic model were reported at the International AIDS conference this year. His team compared the numbers of teens continuously attending the clinic as well as the number showing viral suppression -- meaning virus levels in their blood were undetectable -- between a standard HIV clinic and their adolescent-friendly version.

Their findings showed that catering for the needs of teens and providing peer support in this way resulted in greater numbers attending regularly, with 95% staying, as opposed to 85% in regular clinics. There was also greater viral suppression, with 91% at the teen clinic as opposed to 80% at the regular one.

"They were more likely to be retained in care, so make appointments and collect medication on time," said Zanoni, "(and) more likely to be virally suppressed."

When exploring why there was such a difference, Zanoni added that it was likely to predominantly come down to the peer support the teens receive at the clinic and summer camp but also the removal of stigma due to the clinic being held over the weekend.

"When a kid misses school once a month, every month (to go to the clinic), kids are smart, and they figure out why they're missing school," Zanoni said. "Here, they don't miss school anymore, so that stigma goes away."

Bekker believes clinics tailored to encourage teenagers to attend are vital to help this age group cope with infection.

"The unfortunate norm is that adolescents' HIV treatment outcomes are generally worse than other population groups, (and) there are many reasons for that," she said. "This (study) continues to build the evidence base that shows we need bespoke health services to reach and engage adolescents."

Zanoni now hopes to use this data to apply the model behind these clinics more globally. He has tried to bring teen-friendly clinics to the United States but has faced challenges due to the risk of disclosure beyond the group. Though the same challenges exist in other places, including South Africa, pushback has been greater in the United States.

"There's a lot of politics about disclosure," he said, but he hopes to use his findings to push harder for implementation.

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"If they're going to the clinics anyway to collect their medicines, we might as well make it something that they enjoy," Zanoni said.

As for Chonco, now out of his teen years, he admits that he found it hard to stop going to the clinic once he had become too old and that the experience has also left him wanting to help his fellow patients, so he now volunteers there each week. There, he shares this wisdom to help others make it through that awkward period of time, particularly those avoiding their treatment.

"The information they have is so poor (in my area)," he said. "I tell them the treatment is their life. If you don't take your treatment, you're going to die."