A total of 2312 FSW participated in the baseline surveys, and 2400 participated at follow-up surveys; 399 women (16.6%) reported taking part at both time points. The median age of FSW was 30 years (interquartile range (IQR) 19–41) and the majority (67%) were illiterate (). Six per cent of the study population were devadasis, a group of FSW in northern Karnataka who are part of a long-standing tradition in which adolescent girls are dedicated to gods and goddesses and are subsequently inducted into sex work.
Sociodemographic and sex work characteristics of FSW at baseline and follow-up surveys
FSW reported a median age of sexual debut of 15 years (IQR 11–19), with participants starting to sell sex at a median of 25 years (IQR 15–35). The most frequent places of solicitation of sex were public places (55%) and at home (35%), with a minority (10%) brothel, lodge or dabha-based (hereafter briefly labelled ‘brothel-based’). Approximately 80% of participants reported selling sex for more than 2 years at both survey rounds. Between baseline and follow-up, the mean charge per sex act increased substantially, so that by the follow-up survey, weekly earnings from sex work had nearly doubled (mean weekly earnings baseline 1632 Indian rupees (US$33) vs follow-up 2915 rupees (US$60) (p<0.001) ().
Exposure to the intervention programme
Despite high levels of programme exposure reported at baseline (the baseline surveys were conducted 7–19 months after programme initiation and thus were not ‘true’ baselines), there were large increases (p<0.001) in the proportions of FSW who had been exposed to almost all components of the intervention programme by the time of the follow-up surveys (). Therefore, by follow-up, virtually all FSW (95.3%) had been visited by a peer educator, 76.6% had visited the drop-in centre, 85.1% had visited the project sexual health clinic and 63.6% had received the ‘grey pack’, for presumptive treatment of chlamydia and gonorrhoea (). Furthermore, the proportion of FSW who reported having seen a condom demonstration increased from 73.3% to 89.0%, and the proportion reporting condom breakage in the previous month fell from 17.0% to 14.1% ().
Univariate and multivariate analyses of programme exposure and intermediate causal characteristics among FSW at follow-up compared with baseline
When we stratified FSW according to their reported duration of exposure to the HIV intervention programme (not exposed, <12 months, 12–23 months, 24–33 months, >33 months), the proportion of FSW who reported accessing various components of the intervention programme increased significantly with increasing duration of exposure to the programme (a).
Figure 1 Condom use and HIV/sexually transmitted infection prevalence according to the duration of exposure to the HIV intervention programme. (a) Exposure to programme components and duration of programme exposure. (b) Condom use and duration of programme exposure. (more ...)
At the baseline surveys, levels of reported condom use with clients were already high, with over 65% reporting using a condom at last sex with their last occasional or repeat client (). Reported condom use with regular partners was much lower, with one-third (32%) reporting using a condom at last sex.
Univariate and multivariate analyses of condom-related outcomes and STI prevalence among FSW at follow-up compared with baseline
Compared with baseline, in both univariate and multivariate analyses, there was a substantial increase in the proportion of FSW reporting zero unprotected sex acts in the past month with their commercial clients (). Although the proportion of FSW reporting condom use at last sex with occasional clients increased only marginally from 82.9% to 88.0%, reported condom use at last sex with repeat commercial clients increased substantially from 66.1% to 84.1%. Reported condom use at last sex with regular partners remained stable ().
When FSW were stratified according to their reported length of exposure to the HIV prevention programme, there were striking increases with increasing duration of programme exposure (p<0.01) in all measures of reported condom use, with both commercial clients and regular partners (b).
HIV prevalence was high among this population, with one-fifth of FSW testing HIV-1 seropositive at baseline (). HIV prevalence was highest in Belgaum (33.9%) and Mysore (26.1%), with lower rates seen in Bellary (15.7%), Bangalore Urban (12.7%) and Shimoga (9.7%). Baseline prevalence of bacterial STI was relatively low for a sex worker population, with 10% of participants testing positive for syphilis, 7% for chlamydia and 4% for gonorrhoea. Approximately 6% had high-titre syphilis, indicative of more recent or active syphilis infection ().
At the follow-up survey, HIV prevalence fell significantly, from 19.6% to 16.4% (), with reductions seen in all districts (data not shown). There were also reductions in the prevalence of any syphilis infection and of high-titre syphilis (). Despite low baseline rates, the proportion infected with either chlamydia and/or gonorrhoea also fell significantly ().
In both univariate and multivariate analyses, reductions in chlamydia and/or gonorrhoea infection were strongly (p<0.001) associated with peer education, visiting the project sexual health clinic and receiving the ‘grey pack’, but there were no significant associations between reductions in high-titre syphilis and exposure to any programme component (data not shown). Furthermore, there were no significant associations between reductions in any curable STI and reported condom use (data not shown).
In Mysore district only, FSW were also tested for trichomonas infection in both rounds (data not shown).6
Almost one-third (32.9%) were infected at baseline, but this proportion fell to 13.5% by the follow-up survey (adjusted odds ratio 0.3, 95% CI 0.2 to 0.4, p<0.001).
When we stratified FSW according to their duration of exposure to the HIV intervention programme (), although there were no clear trends for syphilis, rates of infection with chlamydia and/or gonorrhoea fell with increasing programme exposure, from 13% among FSW who had not been exposed to the HIV intervention programme to 3% among FSW exposed for more than 33 months (p<0.001).
HIV prevalence was substantially higher among brothel-based FSW compared with home and street-based FSW, with more than a quarter of brothel-based FSW testing HIV seropositive (). Similarly, infection with gonorrhoea and/or chlamydia was highest in this group, at 12% (). Although the prevalences of curable STI decreased among street-based FSW between the two surveys, those among brothel and home-based FSW remained stable ().
Univariate and multivariate analyses of STI prevalence, condom use and programme exposure at baseline and follow-up, according to usual place of solicitation
Despite these high HIV and STI rates, brothel-based FSW reported higher condom use with their sexual partners, compared with the other typologies (). However, by the follow-up survey, they were less likely to have previously visited the project drop-in centre or sexual health clinic, or to have received a ‘grey pack’, compared with FSW who solicited sex at home or in a public place. Moreover, brothel-based FSW were likely to be younger (mean age 22.6 years brothel-based vs 24.8 years home-based vs 25.1 years street-based, p<0.001), to charge less per sex act (mean charge 154 rupees brothel-based vs 195 rupees home-based vs 227 rupees street-based, p<0.001), and to entertain double the number of clients per week (mean clients per week 22.3 brothel-based vs 9.4 home-based vs 10.7 street-based FSW, p<0.001), compared with home and street-based sex workers. However, despite charging less per sex act, they were likely to earn more per week from sex work compared with the other typologies because of their higher client volume (mean earnings per week 2637 rupees vs 1837 rupees vs 2481 rupees for brothel vs home vs street-based FSW, respectively, p<0.001). In addition, they were more likely to have previously sold sex in Mumbai (6.3% brothel vs 1.7% home vs 2.6% street-based FSW, respectively, p=0.008).