When young girls are sold into marriage, as 38,000 are every day, they can expect a life with no education and few opportunities, little public autonomy outside of their adult husband's control and an increased risk of death from pregnancy or childbirth, which are the number one killer of girls age 15 to 18 in the developing world. One in seven girls born in the developing world is married by age 15, usually sold by her family.

But some girls who grow up in Egypt's poor rural communities face an even scarier sort of child marriage: the temporary kind. Sex tourism to Egypt tends to spike in the summer, when wealthy men from Gulf countries flood into Egypt and thousands of underage girls are sold by their parents into temporary "marriages," according to a story by Inter Press Service.

Child sex tourism is difficult to track, but the United Nations estimates that it affects two million children every year, often in countries that are poor but have preexisting tourism infrastructure, such as Thailand, India, Costa Rica and others.

Egypt's illegal child sex tourism trade appears to have put a regional-friendly spin on the practice by portraying the buying and selling of children as a form of marriage, thus giving them a thin veneer of religious acceptability by circumventing Islamic rules against pre-marital sex. (Despite a 2008 law banning child marriages, enforcement is thought to be low and an Egyptian official told the Inter Press Service that's it's nearly ceased since the chaos of the 2011 revolution.) Child marriages are, after all, somewhat common in Arab countries, although not nearly as common as in neighboring regions. And such child marriages often involve "dowries" that human trafficking activists say are akin to a purchase price.

By making the unions temporary, Egyptian child sex tourism manages to capture much of the worst of child marriage and child prostitution. Girls still bear the long-term risks of child marriages – some are expected to double as domestic workers – as well as the routines of children sold for sex in other countries. "Some girls have been married 60 times by the time they turn 18,” an Egyptian government official who works on the issue told Inter Press Service. "Most ‘marriages’ last for just a couple of days or weeks."

An investigation by an Egyptian government body, the Child Anti-Trafficking Unit at the National Council for Childhood and Motherhood, found that 75 percent of respondents in surveyed rural communities knew girls who were involved in the trade and that most believed that rate was increasing. It estimated that the vast majority of the buyers came from Gulf countries, with 81 percent from Saudi Arabia, 10 percent from the United Arab Emirate and 4 percent from Kuwait.

The study estimates that a summer-long marriage, usually lasting the duration of a seasonal Gulf tourist's visit, cost about $2,800 to $10,000. The unions can at times last a year or two, though; the "bride" is typically expected to travel back to her buyer's home country where she may work as a domestic. One-day marriages can cost as little as $115.

Egypt's economy has been in free-fall since the ouster of President Hosni Mubarak in early 2011, with unemployment rising and public services declining. Rural families, driven apparently by a sense that the practice is socially acceptable and a desperate need for income, pressure daughters to enter the trade at puberty, according to the government study. "The girls know their families have exploited them," the Egyptian official told Inter Press Service. "They can understand that their parents sold them."

Subscribe for the WorldViews daily email update to get the latest headlines delivered to your inbox.