HIV infection rates among teenage girls are often much higher than in teenage boys; the reason lies in girls' greater biological and social vulnerability. Compared with that of males, the female reproductive tract is more susceptible to infection with HIV and other sexually transmitted diseases... And girls often risk infection very early. Compounding this are complex and unhealthy societal expectations that mean girls and young women have less control over their lives and bodies than do their male counterparts. In Thailand, too many girls find themselves at an early age in the sex industry, usually for lack of other options for earning a living. Young girls are desirable because they are thought to be 'safe' and uninfected with HIV, but the risk of infection to them, and thence to their clients, is very high... The reasons that girls enter the sex industry in Thailand have received much attention... The causes have been divided into those at the societal level and those at the family level. At the social level, Thailand's rapid economic development is cited as one major cause. When Thailand adopted an industrialized, export-led economy, one of the consequences was that agriculture - formerly the backbone of the Thai economy - was devalued. Farmers went increasingly into debt and many were forced to search for work in urban areas, usually Bangkok or provincial urban centres. Those who remained in the rural areas tried various alternative family survival strategies, including sending their children to cities to earn. Thailand's national policy, with its emphasis on economic growth, led at the same time to a rise in materialism in Thai society. Parental desires for a better, more comfortable standard of living...led some parents to encourage their children into the sex industry as one means of attaining their material goals. Children who did not accede to their parents' demands were regarded as ungrateful, since respect for one's parents and providing for their care are paramount, socio-cultural norms in Thai society, persisting even under Thailand's rapid social and economic changes. In some rural villages, particularly in northern Thailand, where prostitution has become an acceptable occupation, families who do not sell their daughters may be seen as foolish by other members of the community. More broadly speaking, the main reason for girls entering the sex industry is to satisfy their parents' urgent need for money, in some cases not for more material goods but simply for the family's survival. Earnings from unskilled labour are much lower than those from sex work. Thus, many parents decide to sell their daughters and earn quick money to provide for their immediate needs. Though girls may not want to become sex workers, many are forced or tricked into it. These children usually have little or no education and often do not live with their parents. Another group at special risk are children who live with a stepfather or stepmother. With weaker family ties and often less family support, they have become common targets for recruitment into sex work... The expectation that they will support their parents in any way they can is placed on daughters much more than on sons in Thai society. A daughter's duty is to earn a living for the family to repay her gratitude to the parents, while a son's is to spend time as a monk. Thus, the economic burden of the family is placed on the daughter's shoulder. There is no reported incidence of the selling of sons by their parents, whereas selling daughters is quite common. Indeed, the reason males become prostitutes are different from those for females. One study...in 1994 on male bar workers in Bangkok found that 51 per cent were introduced to the job by their friends and 36 per cent by reading job advertisements. For male sex workers, choosing this job is mainly their own decision. Even though there are far fewer male sex workers than there are females ( a ministry of public health survey in 1997 estimated that there are only 3 or 4 male sex workers for every 100 females), national policies for preventing and solving the problems of sex workers give equal attention to both sexes. But different strategies are needed to cope with the problems facing male and female sex workers... To be continued