Prevalence and risk factors of early onset of sexual intercourse in a random sample of a multiethnic adolescent population in French Guiana.

French Guiana, a French overseas department in South America, has been classified epidemic for HIV. This territory is consisting of a very young population with almost 45% of them being younger than 20 years of age. Delaying the onset of first sexual intercourse (SI) is one of the major objectives to fight HIV infection in adolescents. The objective of this study is to identify the age of first SI and the risk factors of early onset. A behavioural surveillance survey among students living on the coastline and alongside the Maroni River was conducted in 2011/2012. A total of 1603 students filled out the survey. While 60% had already SI, the mean age of first intercourse was 12.1 years for boys and 13.9 years for girls. Accordingly, over 90% had a premature onset of SI. Risk factors are age, male gender, living alongside the Maroni River, another language than the French being mother tongue, not being religious, alcohol and cannabis consumption and a bad attitude towards condom use. Risk factors for girls are an older first sexual partner, having more than three lifetime sexual partners and condom rupture. Evidence-based implementation with respect of local and socio-demographic aspects is necessary to improve youths' appreciation of SI and related risk of sexual transmitted diseases.