We utilized service and unique object multipliers, and 3-source capture-recapture methods in conjunction with a respondent-driven sampling RDS survey to estimate the number of FSW in Juba and Nimule. A total of 2 separate unique object distributions were conducted in Juba and Nimule. In Nimule, these were combined to produce a 3-source capture-recapture estimate. The exercise involved distribution of key chains and bangles to FSW, documentation of the number of those who received unique objects, and questions during RDS survey to assess whether participants received unique objects.
A 3-source capture-recapture estimate could not be produced because aggregate rather than individual level data were collected during the third capture. The service and unique object multiplier, and 3-source capture-recapture methods were successfully used to estimate the number of FSW in Nimule, whereas service and unique object multiplier methods were successfully used in Juba.
These methods yielded higher than previously estimated FSW population sizes. These estimates will inform resource allocation and advocacy efforts to support services for FSW. South Sudan, the newest country in the world, gained independence in This was followed by the return of refugees and foreigners from neighboring countries. The relative stability allowed increased commerce and the apparent increase in the number of female sex workers FSW [ 4 ].
Little data exist on sex workers in South Sudan. Programs for FSW are guided by mapping conducted in and and formative assessments conducted in Despite a period of relative calm after independence, South Sudan experienced political crises in December and July that resulted in significant population movements [ 5 ]. Previous mappings and formative assessments indicated that Juba was home to the largest number of FSW in the country. Nimule, on the South Sudan-Uganda border, was estimated to have sex workers [ 7 ].
Sex work is illegal in South Sudan and sex workers operate in a very stigmatizing environment with the constant threat of arrest, imprisonment, and sexual exploitation [ 6 , 8 ]. This context has led many sex workers to operate in a covert manner, in lodges, brothels, and homes. Street-based sex work is less common [ 4 , 6 ]. Accurate estimation of the size of key populations using empirical methods that include data collection rather than conjecture provides important data for advocacy and resource allocation of HIV programs [ 9 ].
