[show abstract][hide abstract] ABSTRACT: To describe formal, external to programme methods for size estimation of high-risk populations and compare execution challenges and validity of results.
A cross-sectional HIV risk behavioural and biological survey was implemented among 24, 10 and five female sex workers, high-risk men who have sex with men and injecting drug user survey groups, respectively. Size estimates were calculated using three formal methods: capture-recapture, the multiplier method and the reverse tracking method (RTM), a new method.
Estimates were compared with each other and programme data.
In general, when appropriately executed, formal methods produced smaller estimates to programme data, although the RTM tended to be closer to programme estimates.
Capture-recapture requires some knowledge of site location. It can be used as a community mobilization measure at the initiation of a programme. The multiplier method presumes the existence of high quality external data and requires care in selecting the appropriate multiplier. All size estimation methods require careful planning and a full understanding of population dynamics and limitations of data. Before selecting a size estimation method, one must be aware of the strengths, weaknesses and applicability of each method. Use of size estimation methods in large-scale programmes should be considered carefully with adequate importance given to planning and implementation.
[show abstract][hide abstract] ABSTRACT: To characterize and describe patterns of HIV, sexually transmitted infections (STI) and sexual behaviour of male clients of female sex workers (FSW).
A cross-sectional study was conducted among 4821 clients of FSW from 12 districts in three states in India: Andhra Pradesh, Maharashtra and Tamil Nadu. A structured questionnaire was administered to elicit demographic characteristics and sexual behavioural patterns. Blood and urine samples were tested for HIV, syphilis and herpes simplex type 2 serology, gonococcal and chlamydial infection.
The median age of clients surveyed was 30 years; 57% were married and 64% had a steady sexual partner; 61% had sex with more than one FSW and 39% had four or more sexual encounters in the past month. The prevalence of HIV ranged from 2.0% to 10.9%, syphilis ranged from 3.1% to 10.1%; gonorrhoea and chlamydia ranged between 0% and 4.5%. Clients older than 30 years [odds ratio (OR) 1.65; 95% confidence interval (CI) 1.33-2.05] and having a different mix of commercial and non-commercial partners (OR 1.56; 95% CI 1.25-1.96) had a higher volume of sex acts with FSW. Inconsistent condom use with FSW was significantly associated with older clients (OR 4.2; 95% CI 3.33-5.29), illiteracy (OR 1.39; 95% CI 1.14-1.69), age <18 years at first paid sex (OR 1.83; 95% CI 1.24-2.70) and having different FSW partners in the past month (OR 1.64; 95% CI 1.23-2.18).
Clients of FSW studied here constitute a significant bridge group for HIV and other STI, because of their high volume of different sexual partners and very low consistent condom use. HIV prevention programmes need to address male clients.