For the first time an African country has subjected itself to international scrutiny of the rates of mental, physical and sexual violence suffered by girls and boys, and their impact An 11-year-old girl walks along a road with her sister in Tanzania Much is known about the physical health of young Africans. Rates of malnutrition and diarrhoea are benchmarks for aid. But the mental health of children and teenagers has always been draped in a taboo-ridden silence. Now for the first time, an African country Tanzania has subjected itself to international scrutiny of the rates of mental, physical and sexual violence suffered by girls and boys, and their impact. The study, published on Tuesday by Dar es Salaam's Muhimbili University in collaboration with the US Centres for Disease Control and Prevention, finds that nearly three out of every 10 girls and nearly three out of every 20 boys in Tanzania claim to have experienced sexual violence. Almost three-quarters of girls and boys questioned had experienced physical violence before the age of 18 at the hand of an adult or an intimate partner. Around 25% had been subjected to emotional abuse by an adult during childhood. Andrew Brooks, chief of child protection in Tanzania for Unicef, which financed the study, said its findings are difficult to weigh internationally. "In Europe and North America, statistics would be collected differently, through social workers' reports,'' he said. "In Africa, only one other country, Swaziland, has carried out a similar household survey but only girls were interviewed. It is very clear that, by any measure, the Tanzanian figures are quite alarming.'' Jeanne Ndyetabura, assistant commissioner for social welfare in Tanzania's Ministry of Health, said the study would be acted upon. "I would urge other African countries to carry out surveys like this. It's no good saying 'it doesn't happen here' because clearly it does, and we need information,'' she said. Tanzania's Violence Against Children survey saw more than 120 interviewers question 3,739 girls and boys aged between 13 and 24 in their homes. The country has a population of about 44 million, and half are under 18. Of the girls questioned, 27.9% reported experiencing at least one incident of sexual violence before they reached the age of 18. Among boys, 13.4% reported one or more incident of sexual violence. For both girls and boys, this most commonly took the form of sexual touching, followed by attempted intercourse. Of those who were under 18 when they had their first sexual experience, 29.1% of females and 17.5% of males said it was undesired. The ages at which girls and boys were first exposed to sexual violence differed. Just under 20% of girls and 15.6% of boys said they were younger than 14. Physical violence was reported as widespread. Corporal punishment is legal in Tanzanian schools but the levels of violence went far beyond the legally accepted norms: 78% of girls and 67.4% of boys said they had been punched, kicked or whipped more than five times by a teacher before they turned 18. Emotional violence for example the threat of abandonment by an adult was reported from 23.6% of girls and 27.5% of boys. In most cases the adult was a relative. The report's authors say people exposed to any form of violence in childhood are more likely to show health, emotional and behavioural problems in adolescence and adulthood. These include poor physical health, aggression, delinquency, substance abuse, poor academic performance, anxiety and reduced self-esteem. Attitudes to domestic violence were also scrutinised. Nearly 60% of girls and 52% of boys believed it is acceptable for a husband to beat his wife under certain circumstances, including a refusal to have sex, burning the food, going out without telling him or neglecting the children. Brooks, said the groundbreaking study required follow-up. "There needs to be a concerted effort at high level to ensure that the issue of child abuse and child violence becomes part of the agenda for health, education, justice, social welfare and the police response,'' he said. Ndyetabura said moves were already afoot to scale up surveillance and support systems, as means allowed. "On the back of the survey we have put in place child protection systems that are being piloted in three districts. We intend to scale up and replicate the pilots elsewhere. But budgets are, of course, an issue.'' Brooks and Ndyetabura called for a rethink of the international definition of "most vulnerable children'' to include not only health and economic indicators, but also issues of exposure to violence in a quest for its root causes. Of course, children must be vaccinated, clothed and fed, as perceived by the millennium development goals. But they must also have the right to be protected against violence.