Article

Periodic presumptive treatment of curable sexually transmitted infections among sex workers: recent experience with implementation

Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
Current Opinion in Infectious Diseases (Impact Factor: 5.03). 12/2011; 25(1):100-6. DOI: 10.1097/QCO.0b013e32834e9ad1
Source: PubMed

ABSTRACT Curable sexually transmitted infections (STIs) are common occupational hazards for female sex workers in low-income and middle-income countries. Yet, most infections are asymptomatic and sensitive screening tests are rarely affordable or feasible. Periodic presumptive treatment (PPT) has been used as a component of STI control interventions to rapidly reduce STI prevalence.
Six recent observational studies confirm earlier randomized controlled trial findings that PPT reduces gonorrhoea and chlamydia prevalence among sex workers. One modeling study estimated effects on Neisseria gonorrhoeae, Chlamydia trachomatis, Haemophilus ducreyi, and HIV prevalence at different levels of PPT coverage and frequency, among sex workers who take PPT and among all sex workers. Important operational issues include use of single-dose combination antibiotics for high cure rates, conditions for introducing PPT, frequency and coverage, and use of PPT together with other intervention components to maximize and sustain STI control and reinforce HIV prevention.
PPT is an effective short-term measure to rapidly reduce prevalence of gonorrhoea, chlamydia, and ulcerative chancroid among female sex workers. It should be implemented together with other measures--to increase condom use, reduce risk and vulnerability--in order to maintain low STI prevalence when PPT is phased out.

2 Followers
 · 
132 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Haemophilus ducreyi, the etiologic agent of chancroid, has been previously reported to show genetic variance in several key virulence factors, placing strains of the bacterium into two genetically distinct classes. Recent studies done in yaws-endemic areas of the South Pacific have shown that H. ducreyi is also a major cause of cutaneous limb ulcers (CLU) that are not sexually transmitted. To genetically assess CLU strains relative to the previously described class I, class II phylogenetic hierarchy, we examined nucleotide sequence diversity at 11 H. ducreyi loci, including virulence and housekeeping genes, which encompass approximately 1% of the H. ducreyi genome. Sequences for all 11 loci indicated that strains collected from leg ulcers exhibit DNA sequences homologous to class I strains of H. ducreyi. However, sequences for 3 loci, including a hemoglobin receptor (hgbA), serum resistance protein (dsrA), and a collagen adhesin (ncaA) contained informative amounts of variation. Phylogenetic analyses suggest that these non-sexually transmitted strains of H. ducreyi comprise a sub-clonal population within class I strains of H. ducreyi. Molecular dating suggests that CLU strains are the most recently developed, having diverged approximately 0.355 million years ago, fourteen times more recently than the class I/class II divergence. The CLU strains' divergence falls after the divergence of humans from chimpanzees, making it the first known H. ducreyi divergence event directly influenced by the selective pressures accompanying human hosts.
    PLoS ONE 10(3):e0118613. DOI:10.1371/journal.pone.0118613 · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: High rates of partner change in 'upstream' sex work networks have long been recognized to drive 'downstream' transmission of sexually transmitted infections (STIs). We used a stochastic microsimulation model (STDSIM) to explore such transmission dynamics in a generalized African HIV epidemic. We refined the quantification of sex work in Kisumu, Kenya, from the 4-cities study. Interventions with sex workers were introduced in 2000 and epidemics projected to 2020. We estimated the contribution of sex work to transmission, and modelled standard condom and STI interventions for three groups of sex workers at feasible rates of use and coverage. Removing transmission from sex work altogether would have resulted in 66% lower HIV incidence (range 54-75%) and 56% lower prevalence (range 44-63%) after 20 years. More feasible interventions reduced HIV prevalence from one-fifth to one-half. High rates of condom use in sex work had the greatest effect, whereas STI treatment contributed to HIV declines at lower levels of condom use. Interventions reaching the 40% of sex workers with most clients reduced HIV transmission nearly as much as less targeted approaches attempting to reach all sex workers. Declines were independent of antiretroviral therapy rollout and robust to realistic changes in parameter values. 'Upstream' transmission in sex work remains important in advanced African HIV epidemics even in the context of antiretroviral therapy. As in concentrated Asian epidemics, feasible condom and STI interventions that reach the most active sex workers can markedly reduce the size of HIV epidemics. Interventions targeting 'transactional' sex with fewer clients have less impact.
    AIDS (London, England) 01/2014; DOI:10.1097/QAD.0000000000000176 · 6.56 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Female sex workers (FSWs) are at risk for sexually transmitted infections (STIs), including HIV. We implemented an HIV/STI preventive intervention among FSWs in Shanghai that aimed to increase condom use, improve HIV knowledge, and reduce STI and HIV incidence. From six districts in Shanghai, 750 randomly selected venue-based FSWs were allocated to either a behavioural intervention or control group. In the intervention and control groups, 221 and 278 participants, respectively, had at least one follow-up at three or six months. In analysis, we randomly selected 57 lost to follow-up cases in the intervention group and imputed baseline values to equalize the arms at n = 278 (74.1% follow-up rate in each group). The impacts of the intervention on condom use, HIV/STI risk perception and knowledge, and STI incidence were assessed using a logistic or linear model, adjusting for the baseline measure of the outcome and venue type. The intervention improved consistent condom use with any partner type in the previous month (AOR = 2.09, 95% CI, 1.43-3.04, p = 0.0001). Consistent condom use with clients in the three most recent sex acts increased in both arms, and with primary partners in the intervention arm, but there was no difference between groups after adjusting for baseline condom use and venue type. There were no differences in cumulative incidence of any STI (e.g., chlamydia, gonorrhoea, syphilis) between groups. HIV transmission knowledge (p = 0.0001), condom use skill (p = 0.0421), and self-efficacy for using condoms (p = 0.0071) were improved by the intervention. HIV-related stigma was decreased (p = 0.0119) and HIV and STI risk perception were increased (4.6 to 13.9%, and 9.4 to 20.0%, respectively). The intervention was associated with these improvements after adjusting for the baseline measure and venue type. Following a preventive intervention among Shanghai FSWs, our findings demonstrate that a simple, community-based educational intervention improved overall condom use, HIV and STI knowledge, and attitudes in relation to HIV/AIDS. The intervention should be implemented widely after tailoring educational materials regarding condom negotiation with different partner types (e.g., clients and primary partners).
    BMC Public Health 12/2015; 15(1):1439. DOI:10.1186/s12889-015-1439-5 · 2.32 Impact Factor