For decades, Central America has provided fertile territory for human traffickers. Bloody civil wars, the lowly status of women and girls, and the poverty that pushes thousands of migrants northward to the United States, have all played their part in this story.
Rebecca is a bright, animated teenager. As a fourteen year old, she was trafficked from her home in El Salvador to neighbouring Guatemala where she was forced to work in a brothel and beaten regularly. When a severe sexually-transmitted infection prevented her from servicing clients, she was compelled to labour on a farm.
Against the odds, Rebecca escaped. Now she is being looked after back home in El Salvador in the only institution of its kind in Central America - a refuge for children and young women who, like Rebecca, have been sold for sexual exploitation. The very existence of this shelter is a sign that attitudes to trafficking - that it is a crime and that the victims need support - are changing.
Globally, human trafficking is the most lucrative illicit business after drugs and arms. In this week's Crossing Continents, Linda Pressly visits El Salvador and Nicaragua to report on local efforts to take on the traffickers and help their victims and meets some of those individuals determined to make a dent in this trade of human misery.
International co-ordination is vital, and the Central American nations have agreed to repatriate children - like Rebecca - as quickly and efficiently as possible.
Since the beginning of last year, 115 children have been repatriated to Nicaragua alone. One of the poorest nations in the hemisphere, Nicaraguan women and girls are especially vulnerable to the traffickers who promise them jobs in shops and factories and then deliver them to brothels and bars.
Milagros is a Nicaraguan who fell for the traffickers' story. Thinking she was heading for a respectable job in a casino, she found herself a prisoner in a brothel in El Salvador. But collaboration between the police authorities of Nicaragua and El Salvador led to Milagros' rescue, and the prosecution of at least some of her captors.
BBC Radio 4's Crossing Continents will be broadcast on Thursday, 13 December 2007 at 1102 GMT. It will be repeated on Monday, 17 December 2007 at 2030 GMT
Reporter and Producer: Linda Pressly