MAPUTO, Mozambique – When Flavia Meringue gets to work in the morning, her inbox is full of intimate questions from children, some as young as 10, asking questions like, “Should I be having sex yet?”

She and 11 other counselors at the Coalizao youth center in Mozambique’s capital Maputo answer hundreds of queries a day from people who use their phones to text in, anonymously and for free. They range from the curious – “What’s the maximum depth of a vagina?” – to the dangerous, perpetuating common myths about HIV/AIDS: “Do condoms transmit HIV?” and “Will having sex with a virgin cure me of HIV?”

In Mozambique, 11.5 percent of the population aged 15 to 49 has HIV/AIDS. According to UNICEF, girls and young women are three times more likely to be HIV-positive than boys and young men, and to get infected at an earlier age. Much of that, say health experts, is due to the fact that half of Mozambican girls are married before their 18th birthday – in northern provinces, a quarter of girls are married by age 15 – often to older men who have more than one wife. UNICEF says a third of Mozambican children are sexually active by age 14, but general knowledge of HIV prevention methods is low.

To have any chance of stemming the rate of HIV infection among Mozambique’s young people, adults have to stop denying children information about sexual and reproductive health, so that they can distinguish myth from fact and protect themselves, says Meringue. But in a conservative society where discussing sex is taboo – both at home and at school, where sex education is often on the curriculum but largely ignored – leading the next generation out of the dark requires some innovation.

UNICEF launched its SMS BIZ text message service in October in four provinces, including Maputo, where almost 20 percent of the adult population has HIV/AIDS. The service currently has around 36,000 subscribers aged between 10 and 24 years, and UNICEF hopes to reach 50,000 subscribers by the end of 2016.

The results of Coalizao’s pre-launch surveys showed a real need for accurate information about avoiding and coping with HIV. Even in the capital, rumors about the virus still swirl around the streets. “When you speak to siblings and parents, there’s a risk of getting the wrong information,” says Meringue.

Four hours north in Gaza province, where 25 percent of people aged 15 to 49 have HIV, nurse Amelia Langa sits in a small room at Xai-Xai secondary school surrounded by pills, injectables and wooden or foam replicas of human genitalia. The majority of children who come to see her in this private space next to the basketball court are 13- to 14-year-old girls wanting to know about contraception and pregnancy.

In this school of around 5,000 pupils – split between morning and afternoon sessions – Langa has easily hit or surpassed her target of testing 250 children for HIV a month since she started in April. Each month, only two or three tests come back positive.

While poverty pushes many girls out of school and down the aisle, the children at Xai-Xai are part of Mozambique’s lucky 8 percent who manage to attend secondary school. That means they have the best chance of getting informed about sexual and reproductive health. But even among this relative elite, HIV prevention is still a mystery to many teenage girls. “The biggest challenge is the awareness about condom use,” says Langa. “We try to tell them that if you test negative you still need to use condoms, and if you test positive you shouldn’t give up and should take the treatment.”

A few minutes’ drive from Xai-Xai, where tarmac turns to dirt road and brick houses are replaced by homes of wood and dried reeds, is Chibuto village. Pupils at Chimundo secondary school at the heart of the village have been using SMS BIZ since April, but the general level of knowledge about HIV and AIDS remains low.

Francesca, whose mother was diagnosed with HIV when she was pregnant with her, believes that you catch the virus from sharing bowls and cups with someone who has been infected, because that’s what her primary school teacher and her mother told her. Francesca, 16, has never questioned this information, or her own status – her mother has assured her that she is negative. At the same time, Francesca has been sworn to secrecy about her mother’s HIV status, to keep the community from ostracizing her. “My auntie who has HIV and didn’t take the medicine got really thin, and people started talking badly about her,” she says.

Like many girls attending Chimundo, Francesca has started having sex with her boyfriend. “We are using condoms because I’m not sure that I trust him,” she says. But many Mozambican girls don’t get a say in who they have sex with, or when. “You see a lot of 12- or 13-year-olds with a baby coming for consultations at the health center,” says Guillermo Marquez, UNICEF Mozambique’s HIV specialist.

Low school attendance rates for girls feed into a cycle of ignorance about the risks and consequences of HIV. “The majority of our girls give up school because they face marriage at early age,” says English teacher Shady Zita. “Some of them end up getting married to sort out financial problems in their families, so any person who comes in front of them, for them, it’s welcome to get out of poverty.”

But the result of these “very many small girls getting married” can be deadly, says Zita. “In the countryside, in a place like Chibuto, there’s a lot of polygamy, and there’s a negative effect in terms of new infections.”

Back in Maputo, the SMS BIZ counsellors advise those who think they are at risk to get tested at their nearest clinic. Even when the results come back, the denial is strong. “When people find out that they are HIV-positive they react badly, as they think that without physical aspects like getting thin or spots, they can’t have it,” says Meringue.

She and other counselors also have to persuade people to stay on their antiretroviral medicines so they can live longer and healthier lives, and prevent the virus from spreading to their babies or partners. Some people stop taking the drugs because they feel better and can’t see any physical manifestations of the illness. There are also huge challenges around persuading children to take antiretroviral treatment for life. Due to stigma, children fear being seen taking a daily pill, let alone admitting they have HIV, for fear of being bullied or excluded.

A text message may seem like an impersonal way to deal with such an intimate issue, but Meringue says, for some people, having a counselor at their fingertips to allay their worst of fears and doubts can be a lifesaver. “I’m responding to questions from people who are very private, and I know it’s working because I get feedback from people who are so grateful,” she says.

Some names have been changed to protect the identities of children with HIV-positive parents.

Hannah McNeish reported from Mozambique with the help of the International Reporting Project (IRP).