Catherine M Lowndes

Decline in the prevalence of HIV and sexually transmitted diseases among female sex workers in Cotonou, Benin, 1993-1999.

Background Within an ongoing HIV/STD prevention project aimed at female sex workers (FSW) in Cotonou, Benin, we evaluated time trends in HIV and STD prevalences from 1993 to 1999. Design Three serial cross-sectional surveys were conducted in 1993 (n = 374), 1995–1996 (n = 365), and 1998–1999 (n = 591). A questionnaire was administered to the FSW and they were screened for HIV, syphilis, Neisseria gonorrhoeae, and Chlamydia trachomatis. Results The mean percentage of condom use with clients in the week preceding the interview increased from 62.2% in 1993 to 80.7% in 1998–1999 (P = 0.0001). The prevalence of all infections decreased significantly (all P < 0.02; chi-square for trend) over time: HIV from 53.3% in 1993 to 40.6% in 1998–1999; syphilis from 8.9 to 1.5%; gonorrhoea from 43.2 to 20.5%; and chlamydia from 9.4 to 5.1%. However, the mean age of FSW decreased from 31.0 to 28.4 years between 1993 and 1998–1999. Moreover, the country of origin of these women changed dramatically over time: the proportion of Ghanaian women decreased from 66.3% in 1993 to 21.6% in 1998–1999 when the predominant group became Nigerian (38.0%). When controlling for age and country of origin, HIV prevalence was stable over time (P = 0.71), whereas the downward trend remained significant for syphilis and gonorrhoea (both P < 0.001), and was present but not significant for chlamydia (P = 0.13). Conclusion These data suggest that the time trends in HIV and STD prevalences are partly due to the changing sex work milieu, but that the intervention also had an impact. Prevention programmes aimed at FSW should be highly prioritized.

Evaluation design for large-scale HIV prevention programmes: the case of Avahan, the India AIDS initiative

Background:Closing the HIV prevention gap to prevent HIV infections requires rapid, worldwide rollout of large-scale national programmes. Evaluating such programmes is challenging and complex, requiring clarity of evaluation purpose and evidential approaches substantively different to those employed for pilots and small programmes. Objectives:This paper describes the evaluation design for the implementation phase of Avahan, the India AIDS initiative, a large HIV prevention programme funded by the Bill and Melinda Gates Foundation. Avahan, which began in December 2003, has a 10-year charter to impact the Indian epidemic and its response by implementing an HIV prevention programme targeting core and bridge groups in 83 districts of six Indian states, transferring the programme to the Government of India, and disseminating programme learning. Methods:The foundation commissioned an external process to design Avahans evaluation framework. An independent advisory group oversees and guides course corrections in the execution of this framework. Results:Avahans evaluation framework comprises: trend and synthetic analysis of data from core, bridge and household biobehavioural surveys in a subset of intervention districts, denominator estimates and programme monitoring from all intervention districts, and governments antenatal surveillance (two sites per district in all districts); bespoke transmission dynamics modelling to estimate infections averted (subset of districts); cost effectiveness studies (subset of districts). In addition, there are other knowledge-building and quality-monitoring activities. Conclusion:Rather than a small set of monofocal outcome measures, scaled programmes require nuanced evaluations that approximate programmatic scale by collecting data with different levels of geographical scope, synthesize multiple data and methods to arrive at a composite picture, and can cope with continuous environmental and programme evolution.

Decreased susceptibility to cephalosporins among gonococci: data from the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP) in England and Wales, 2007–2011

BACKGROUNDnEffective treatment of gonorrhoea is fundamental to public health control; however, the ability of Neisseria gonorrhoeae to successively develop resistance to different treatments has hampered control efforts. The extended-spectrum cephalosporins--cefixime and ceftriaxone--have been recommended in the UK for treatment of gonorrhoea since 2005. We looked at surveillance data from England and Wales to ascertain the current usefulness of these drugs and to inform changes to national treatment guidelines.nnnMETHODSnWe obtained data from the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP) for patients attending 26 genitourinary medicine clinics in England and Wales between 2007 and 2011. We did analyses with univariate and multivariable logistic regression methods to identify trends in susceptibility to cephalosporins and risk factors associated with infection with isolates with decreased susceptibility to cefixime, and we assessed changes in prescribing practices. We did molecular typing to investigate genetic relatedness of non-susceptible isolates.nnnFINDINGSnThe prevalence of decreased susceptibility to both cefixime and ceftriaxone rose between 2007 and 2010 but was more noticeable for cefixime (an increase from 1·5% in 2007 to 17·1% in 2010), with a bimodal distribution of minimum inhibitory concentration recorded between 2009 and 2010. By multivariable analysis, isolates with decreased susceptibility to cefixime were associated with infection in men who have sex with men (odds ratio 5·47, 95% CI 3·99-7·48; p<0·0001) and year of isolation (in 2010, 13·08, 7·49-22·8; p<0·0001). Such isolates had a largely clonal population, with most belonging to genogroup G1407 and harbouring the penA mosaic gene. Data from 2011 showed a significant decline in prevalence of isolates with decreased cefixime susceptibility, falling from 17·1% in 2010 to 10·8% in 2011 (p<0·0001), concomitant with the change in prescribing practice in 2010 from cefixime to ceftriaxone plus azithromycin.nnnINTERPRETATIONnGuidance for treatment of gonorrhoea in England and Wales was changed in 2010 to prolong the use of cephalosporins. The decline in prevalence of isolates with decreased cefixime susceptibility cannot be attributed unequivocally to this change in prescribing practice; however, the association is striking.nnnFUNDINGnDepartment of Health (England), Public Health England.

The central role of clients of female sex workers in the dynamics of heterosexual HIV transmission in sub-Saharan Africa.

In this issue Cote´ et al. present the results of a very interesting study on clients of female sex workers (FSW) in Accra Ghana which adds weight to the growing body of evidence demonstrating the importance of core and bridging groups in the HIV epidemic in sub-Saharan Africa. Quantitative analyses demonstrating the central role of clients of FSW as a bridging population in the transmission dynamics of HIV in West African setting have been previously published. Cote´ et al. have extended this work by estimating the population attributable fraction (PAF) of sexual contact with FSW in prevalent HIV infections among adult men. The results of this analysis confirm the central role of transactional sex in the HIV epidemic Accra with a best estimate of 84% for this PAF and range of 47 to 100% according to a sensitivity analysis where the level of uncertainty of the parameters used for the PAF estimation has been taken into account. Interestingly in Cotonou (Benin) a setting where the differential in HIV prevalence between clients of FSW and the general population of men is higher than Accra but where the estimated proportion of adult men having sex with FSW is lower a recent estimation the PAF for prevalent male HIV infections related sexual exposure to FSW was 76%. (excerpt)

To what extent is the HIV epidemic in southern India driven by commercial sex? A modelling analysis.

Background:In south India, general population HIV prevalence estimates range from 0.5 to 3%. To focus HIV prevention efforts, it is important to understand whether HIV transmission is driven by commercial sex. Methods:A dynamic HIV/sexually transmitted infection transmission model was parameterized using data from Belgaum and Mysore in south India. Fits to sexually transmitted infection/HIV data from female sex workers (FSWs) and their clients for each district were obtained. Model HIV/herpes simplex virus-2 (HSV-2) prevalence projections for the general population were cross-validated against empirical estimates not used to fit model. The model estimated the proportion of incident HIV/HSV-2 infections due to HIV/HSV-2 transmission between FSWs/clients, their noncommercial partners and other low-risk partnerships. The relative impact of a generic intervention targeting different partnerships was explored. Results:The models general population HIV/HSV-2 prevalence projections agreed well with empirical estimates. Recent increases in condom use resulted in decreasing HIV epidemics in both settings. For men, most incident HIV/HSV-2 infections (>90%) directly result from commercial sex, whereas for women most are due to bridging infections from clients of FSWs (80–90%) with the remainder mainly due to commercial sex. Less than 1.5% of incident infections are due to low-risk partnerships. Intervention impact is maximized through targeting commercial sex but substantial impact could also be achieved through targeting noncommercial partners of clients. Discussion:In southern India, HIV transmission could be driven by FSWs and their clients. While efforts to reduce HIV transmission due to commercial sex must continue, prevention programmes should also consider strategies to prevent transmission from clients to their noncommercial partners.

Evaluating large-scale HIV prevention interventions: study design for an integrated mathematical modelling approach

Background: There is an urgent need to evaluate HIV prevention interventions, thereby improving our understanding of what works, under what circumstances and what is cost effective. Objectives: To describe an integrated mathematical evaluation framework designed to assess the population-level impact of large-scale HIV interventions and applied in the context of Avahan, the Indian AIDS Initiative, in southern India. The Avahan Initiative is a large-scale HIV prevention intervention, funded by the Bill & Melinda Gates Foundation, which targets high-risk groups in selected districts of the six states most affected by the HIV/AIDS epidemic (Maharashtra, Karnataka, Tamil Nadu, Andhra Pradesh, Nagaland and Manipur) and along the national highways. Methods: One important component of the monitoring and evaluation of Avahan relies on an integrated mathematical framework that combines empirical biological and behavioural data from different subpopulations in the intervention areas, with the use of tailor-made transmission dynamics models embedded within a Bayesian framework. Results: An overview of the Avahan Initiative and the objectives of the monitoring and evaluation of the intervention is given. The rationale for choosing this evaluation design compared with other possible designs is presented, and the different components of the evaluation framework are described and its advantages and challenges are discussed, with illustrated examples. Conclusions: This is the first time such an approach has been applied on such a large scale. Lessons learnt from the CHARME project could help in the design of future evaluations of large-scale interventions in other settings, whereas the results of the evaluation will be of programmatic and public health relevance.

European surveillance of antimicrobial resistance in Neisseria gonorrhoeae

Objective To perform a European sentinel surveillance study for antimicrobial resistance (AMR) in Neisseria gonorrhoeae as part of the European Surveillance of Sexually Transmitted Infections Programme. Methods From 2006 to 2008 17 countries participated in the AMR surveillance programme. The susceptibility of a total of 3528 consecutive isolates was tested using the agar dilution breakpoint technique or Etests for ciprofloxacin, penicillin, tetracycline, azithromycin, spectinomycin and ceftriaxone. Nitrocefin was used to detect β-lactamase activity. Results Rates of resistance to ciprofloxacin, the previously recommended treatment, were high across Europe (42–52%), indicating that usage is no longer appropriate. Although resistance to the currently recommended treatment, ceftriaxone, was not demonstrated, a concerning upward drift in the minimal inhibitory concentration (MIC) distribution was identified since an earlier European study in 2004. No resistance to spectinomycin was seen, whereas azithromycin resistance varied from 2% to 7% and isolates from Scotland (n=4) and Ireland (n=1) showed high-level resistance (MIC >256u2005mg/l). High-level resistance to tetracycline and penicillin remained relatively constant at 16% and 12%, respectively. Conclusions AMR is an ongoing problem in Europe, with high rates of resistance to many previously recommended therapeutic agents observed in many European countries. Continual European and global surveillance of AMR in N gonorrhoeae is essential to monitor for increasing, emerging and high-level resistance to therapeutically relevant agents and to inform treatment guidelines so optimum treatments are administered.

Epidemiology of, and behavioural risk factors for, sexually transmitted human papillomavirus infection in men and women in Britain

Objectives Persistent infection with high-risk sexually transmitted human papillomaviruses (HR-HPVs) can lead to development of cervical and other cancers, while low-risk types (low-risk HPV) may cause genital warts. We explored the epidemiology of different HPV types in men and women and their association with demographic and behavioural variables. Methods We analysed data collected for the British National Survey of Sexual Attitudes and Lifestyles, a cross-sectional survey undertaken in 1999–2001. Half of all sexually experienced male and female respondents aged 18–44u2005years were invited to provide a urine sample. We tested 3123 stored urine samples using an in-house Luminex-based HPV genotyping system. Results HPV DNA was detected in 29.0% (95% CI 26.7% to 31.3%) of samples from women and 17.4% (95% CI 15.1% to 19.8%) from men. Any of 13 HR-HPV types was detected in 15.9% (95% CI 14.1% to 17.8%) of women and 9.6% (95% CI 8.0% to 11.6%) of men. HPV types 16/18 were found in 5.5% (95% CI 4.5% to 6.8%) of women and 3.0% (95% CI 2.1% to 4.3%) of men; and types 6/11 in 4.7% (95% CI 1.8% to 5.9%) of women and 2.2% (95% CI 1.5% to 3.1%) of men. In multivariate analysis, HR-HPV was associated with new partner numbers, in women with younger age, single status and partner concurrency, and in men with number of partners without using condom(s) and age at first intercourse. Conclusions HPV DNA was detectable in urine of a high proportion of the sexually active British population. In both genders, HR-HPV was strongly associated with risky sexual behaviour. The minority of HPV infections were of vaccine types. It is important to monitor HPV prevalence and type distribution following the introduction of vaccination of girls.

Injection drug use, commercial sex work, and the HIV/STI epidemic in the Russian Federation.

Given this situation there is an urgent need both for research into the determinants of epidemic heterosexual HIV spread in the Russian context and for the implementation of interventions targeted toward sex workers. In order to assess the likely extent of the heterosexual HIV epidemic in Russia it is important to obtain detailed behavioral data (including qualitative and quantitative data on sexual networking) and STI/HIV prevalence data for both sex workers and their sex partners in order to (1) assess and appreciate the severity of the HIV/STI epidemiologic situation in this population; (2) understand the role of commercial sex work in the dynamics of the HIV/STI epidemic in Russia; (3) design appropriate interventions; and (4) monitor the situation over time including potential indications of the impact of preventive interventions. at multiple levels is required to reduce stigmatization and marginalization of sex workers by society as well as their victimization and exploitation by police to reverse the negative attitudes of sex workers about state structures (including health services) and to facilitate the implementation of pragmatic public health interventions by both the state and nongovernmental organizations. (excerpt)

Men who have sex with men and women in Bangalore, South India, and potential impact on the HIV epidemic

Objective The aim of this study was to quantify differences in patterns of sexual behaviour among men who have sex with men and women (MSMW) compared with men who have sex with men only (MSMO), and to examine the extent to which bisexual behaviour may act as a bridge for introducing HIV infection into the general population. Methods A cross-sectional survey in Bangalore city in 2006, which sampled men seeking sex with men in public places and hammams (bath houses where transgender individuals sell sex to men). Results Among a sample of 357 men reporting same-sex behaviour; 41% also reported sex with a woman in the past year and 14% were currently married to a woman, only two of whom had informed their wives about having sex with men. Condom use was very inconsistent with all male partners, while 98% reported unprotected vaginal sex with their wives. MSMW reported lower rates of risky behaviour with other men than MSMO: fewer reported selling sex (17% vs 58%), or receptive anal sex with known (28% vs 70%) or unknown (30% vs 59%) non-commercial partners. Conclusion Bisexual behaviour was common among men seeking sex with men sampled in this survey. Although MSMW reported lower rates of risky sexual behaviour with male partners than MSMO, inconsistent condom use with both male and female partners indicates a potential means of HIV transmission into the general population. HIV prevention programmes and services should reach bisexual men who potentially expose their male and female partners to HIV.