HIV prevalence in sex workers
It measures progress on reducing HIV prevalence among sex workers.
Sex workers typically have higher HIV prevalence than the general population in both concentrated and generalized epidemics. In many cases, prevalence among these populations can be more than double the prevalence among the general population. Reducing prevalence among sex workers is a critical measure of a national-level response to HIV.
Countries with generalized epidemics may also have a concentrated sub-epidemic among sex workers. If so, it is valuable to calculate and report on this indicator for this population.
Number of respondents who test positive for HIV.
Number of respondents tested for HIV.
Numerator / Denominator
UNAIDS and WHO Working Group on Global HIV/AIDS and STI Surveillance: Guidelines among populations most at risk for HIV (WHO/UNAIDS, 2011).
This indicator is calculated using data from HIV tests conducted among respondents in the primary sentinel site or sites.
The sentinel surveillance sites used for the calculation of this indicator should remain constant to allow for the tracking of changes over time.
• Sex (female, male, transgender)
• Age (<25/25+)
< (less than) 25 years
> (greater than) 25 years
In theory, assessing progress in reducing the occurrence of new infections is best done through monitoring changes in incidence over time. However, in practice, prevalence data rather than incidence data are available. In analyzing prevalence data of sex workers for the assessment of prevention programme impact, it is desirable not to restrict analysis to young people but to report on those persons who are newly initiated to behaviours that put them at risk for infection (e.g. by restricting the analysis to people who have or participated in sex work for less than one year) This type of analysis also has the advantage of not being affected by the effect of ART in increasing survival and thereby increasing prevalence.
If prevalence estimates are available disaggregated by greater than and less than one year in sex work countries are strongly encouraged to report this disaggregation in their Country Progress Report, and to use the comments field in the reporting tool for this indicator to present disaggregated estimates.
Due to difficulties in accessing sex workers, biases in sero-surveillance data are likely to be far more significant than in data from a more general population, such as women attending antenatal clinics. If there are concerns about the data, these concerns should be reflected in the interpretation.
An understanding of how the sampled population(s) relate to any larger population(s) sharing similar risk behaviours is critical to the interpretation of this indicator. The period during which people belong to a key population is more closely associated with the risk of acquiring HIV than age. Therefore, it is desirable not to restrict analysis to young people but to report on other age groups as well.
Trends in HIV prevalence among sex workers in the capital city will provide a useful indication of HIV-prevention programme performance in that city. However, it will not be representative of the situation in the country as a whole.
The addition of new sentinel sites will increase the samples representativeness and will therefore give a more robust point estimate of HIV prevalence. However, the addition of new sentinel sites reduces the comparability of values. As such it is important to use consistent sites when undertaking trend analyses.
If the data are subnational, please provide the disaggregation by administrative area in the comment field. Please submit the digital version of any available survey reports using the upload tool.
Several countries have in previous reporting rounds reported HIV prevalence among subpopulations of transgender women through the additional comments field in the GARPR online reporting tool. This demonstrates that the data are feasible to obtain in different settings.
For further information, please consult the following links:
Revised guidelines on HIV surveillance for key populations at higher risk: WHO/UNAIDS Working Group on Global HIV/AIDS and STI Surveillance. Guidelines on surveillance among populations most at risk for HIV. Geneva, UNAIDS, 2011 (http://www.unaids.org/en/media/unaids)
Operational Guidelines for Monitoring and Evaluation of HIV Programmes for Sex Workers, Men who have Sex with Men, and Transgender People. MEASURE Evaluation (www.cpc.unc.edu/measure/publications/ms-11-49a).