Subnational and national estimated numbers of FSW reported in published and unpublished literature, as well as from field investigators involved in research or interventions targeted at FSW, were collected.
The proportion of FSW in the adult female population was calculated. Subnational estimates were extrapolated to national estimates if appropriate. Population surveys were scanned for proportions of adult women having sex in exchange for money or goods. Population surveys from this same region yielded even higher proportions of women involved in transactional sex. The national FSW prevalence in Asia ranged between 0. Estimates from rural areas were only available from one country.
Although it is well known and accepted that FSW are a highly vulnerable group in the scope of the HIV epidemic, most countries in the world do not know the size of this population group. In many countries, the HIV epidemic is concentrated in subgroups of the population whose behaviour exposes them to a high risk of acquiring HIV infection.
These subgroups include injecting drug users, men who have sex with men, and commercial sex workersβfemale and male. Numerous studies have documented significantly higher rates of HIV infection in women involved in sex work, when compared to women in the general population.
In addition, in some countries with low level or concentrated epidemics, prevention efforts targeting high risk populations such as commercial sex workers have been effective in changing the dynamics of the epidemic. Conducting surveillance and developing appropriate interventions require an understanding of the different types of sex work and the size of this population group. Sex work has many faces with considerable differences between populations, in the way sex work is organised, in levels of visibility, and in risk.
