Capture-recapture to estimate the number of street children in a city in Brazil

Background: Street children are an increasing problem in Latin America. It is however difficult to estimate the number of children in the street as this is a highly mobile population.

Aims: To estimate the number of street children in Aracaju, northeast Brazil, and describe the characteristics of this population.

Methods: Three independent lists of street children were constructed from a non-governmental organisation and cross-sectional surveys. The number of street children was estimated using the capture-recapture method. The characteristics of the children were recorded during the surveys.

Results: The estimated number of street children was 1456. The estimated number of street children before these surveys was 526, although non-official estimates suggested that there was a much larger population. Most street children are male, maintain contact with their families, and are attending school. Children contribute to the family budget a weekly average of R$21.2 (pound4.25, (sic)6.0, US$7.5) for boys and R$17.7 (pound3.55, (sic)5.0, US$6.3) for girls.

Conclusion: Street children of Aracaju have similar characteristics to street children from other cities in Brazil. The capture-recapture method could be a useful method to estimate the size of this highly mobile population. The major advantage of the method is its reproducibility, which makes it more acceptable than estimates from interested parties.