"When am I going to die?" asked Lisa when she was told she was HIV positive. It wasn't a question of if but when, in the 12-year-old's young mind and she was terrified. There was a second bombshell, too. The woman who had been looking after Lisa for years turned out not to be her mother but, in fact, her aunt. Lisa's real mother, she learned, had died from HIV-related illnesses when she was four and her aunt had taken her in. What's more, Lisa discovered that the death of her younger sister – whom she was very close to – two years previously was also due to HIV-related illnesses.
"I was so angry," says Lisa, who is now 19 and living in London. "I felt betrayed. Half of my life was lies. I didn't speak to anyone in the family for three weeks – just shut myself in my bedroom. I was on the verge of running away."
The truth came out after Lisa had become suspicious about the "vitamin" pills she'd been taking every day as long as she could remember. "My friends didn't have to take them, so I told my 'mum' I was going to look them up on the internet. Around the same time, I'd started to be curious about why my 'mum' had a different surname. That's when it all came out."
Lisa's story is shocking but not unique. Good practice guidance suggests children should be told if they are HIV positive before they start secondary school but, according to charities, this usually means an abrupt disclosure at a difficult time, and often a trail of lies that have kept the secret alive. "And because the secret has been kept so long, some families don't tell children even then. I know one girl who found out when she was 18," says Lisa.
As if that's not enough to cope with, these young people – of whom there are an estimated 1,200 in the UK – often then face discrimination if they tell anyone (which means many therefore don't). "You get called things like 'Aids victim' at school and you get accused of giving other people Aids just by touching them," says Lisa. "It can be extremely isolating."
No wonder Lisa is so keen to bring about change. She is now a camp leader at a summer camp for children with HIV, where she runs workshops and does peer mentoring. In addition, she sits on a youth committee, advising health professionals about young people's views on living with HIV. She also speaks at conferences and recently did a tour, ending at the Houses of Parliament, talking to university students about living with HIV.
Above all, says Lisa, she wants young people to avoid the kind of experience she had. "Although the one thing I can't fault is the support I've had from the hospital," she says. "When my aunt decided I should know about HIV, she asked the nurse who had done my three-monthly check-ups over the years to tell me. And he was brilliant, immediately putting me straight about the difference between Aids and HIV, answering all my questions, no matter how trivial, and giving me lots of booklets, much of it in easy-to-understand diagrams. He said I could ring him any time."
Everything else, however, felt catastrophically negative. "The trust had completely broken down with my aunt. I had some memories of my mother, but my aunt had looked after me from when she was ill, so I completely accepted her as my mother and assumed my mother was my aunt. I know she felt bad about lying because she cried when she told me the truth and gave me a photo album of my mother. I knew she felt bad about lying to me about the HIV, too, and had just been following guidelines. But while I understood and forgave her in time, I no longer trusted her and home wasn't a happy place any more."
School was no sanctuary, either. "I took two weeks off because there was so much to get my head around, and even when I did go back, rumours had gone round that I had full-blown Aids and there were flyers and posters about me in the classroom. Guys I'd dated made threats and people called me awful names. I had to enter school the back way and take my GCSEs in a private room." Lisa's saviour turned out to be Body & Soul, a pioneering London-based charity dedicated to transforming the lives of children, teenagers and families living with, or affected by, HIV. "It's basically a youth club, but it has everything from workshops to dancing to counselling, all related to HIV. I met my first proper boyfriend there and met my best friends there, friends I know I'll have for life. To say it was amazing is an understatement. These were people who understood what it was like, and I surrounded myself with them."
Back at home, things went from bad to worse and by 15, Lisa was in foster care. Realising that she'd probably benefit from an even stronger support network, Lisa's nurse told her about a new summer camp run by the Children's HIV Association (CHIVA). "At first, I wasn't keen," admits Lisa. "Why would I want to go away for a week with people I didn't know? But eventually, I agreed to give it a try and it changed my life. There were 100 young people, all living with HIV and because there's a whole residential week of workshops, activities, drama and dance all focused on HIV, it's very intense and emotional. By the time I left, these people were like my family and I've gone back every year since, the last time as a camp leader. It's incredible watching some people come in really depressed, with low self-esteem and resentment about having HIV, leaving after just a week in a really positive frame of mind. It's quite a journey."
Lisa was struck by how many of the young people on the camp had no access to anything like Body & Soul. "I live in London, where there are various support groups, but for many people, it's the first time they've met anyone else with HIV. Lots have never talked about it openly and many arrive with misconceptions, for example around risk of transmission and how important it is to take medications. Yes, these people have hospital visits, usually every three months, but they won't all have great nurses like I did and many aren't encouraged to ask questions or are shy."
Lisa returned from the week buzzing. "I became determined to help put a stop to all the ignorance out there and to help bring about a society in which it's OK for kids to grow up knowing their status. Sadly, none of this will happen if people like me keep quiet."
There's a long way to go, she says. Indeed, the very fact that Lisa felt she couldn't show her face in the photographs for this article speaks volumes. "Part of me really wanted to. It's not as if I'm embarrassed about my status. But the other part of me knows that I could face some nasty threats if I admit to it in a national newspaper."
It's exhausting answering the same old questions from the young people she talks to, says Lisa. "The classics are, 'Can you have a boyfriend? Can you have sex? Will your kids have it? Will you die?' But I can't blame them for asking. I only have to think back to my first question when I was told I'm HIV positive."
BBC Children in Need supports both Body & Soul and Children's HIV Association. For more information, visit bbc.co.uk/pudsey