bluuebunny/crossref_metadata_2025 huggingface dataset:
O5-S1.04 Social media and chlamydia testing by university students: a pilot study
Authors: Turner A Norris , Comston T , Davis J , Nasrin Z , Vaughn J
Published: July 2011

Background

Facebook is the world's largest social media site, and university students comprise one of the largest user groups. Sexually transmitted infections are also highly prevalent among university students in the USA. We evaluated a targeted Facebook advertisement for easy, inexpensive chlamydia testing at The Ohio State University (OSU), a public university with 55 000 students.

Methods

Over 2 weeks in May 2010, our advertisement for $25 chlamydia testing was displayed to Facebook users who had self-identified as OSU students between 19 and 28 years of age. Students provided a urine sample directly to the laboratory; a clinician visit was not required. To a separate convenience sample we administered a short survey capturing demographics, social media use and interest in future testing.

Results

The advertisement received 401 732 impressions” (displays of the advertisement to users). Nearly all 98%) impressions were to 19–24-year-olds. The daily impressions varied enormously, from 0 to more than 100 000. In the first week, although the advertisement received up to 2,900 daily impressions, no one clicked it. We gradually increased our “bid per click”—the amount we agreed to pay Facebook for each click—from $0.62 to $0.90. We also modified the advertisement format to depict a college student and to clearly specify the $25 cost of the test. Following these changes, both the number of impressions and “clicks” rose dramatically. Seventy-five individuals clicked the advertisement (25 women and 50 men), with an average cost per click of $0.84. Three students, all female, came for chlamydia testing; one tested positive. Among surveyed individuals (n=60), 75% reported using Facebook daily or more often. Few (10%) reported ever clicking on Facebook advertisements. Only one surveyed student noticed our Facebook advertisement. The direct-to-laboratory testing concept was popular, with 75% reporting willingness to use this service in the future.

Conclusions

In this short pilot study, 75 individuals clicked on a Facebook advertisement about chlamydia testing, three came for testing and one tested positive. Facebook advertisements are inexpensive, with high exposure to the target population. A small increase in bid per click can make a very large difference in total impressions. The format of the advertisement is critical for catching the attention of the target audience, because many students report never noticing or clicking Facebook advertisements.
O5-S2.02 Delay of entry into care in HIV positive individuals
Authors: van Veen M , de Wolf F , Heijman T , Zaheri S , Fennema H , Götz H , van der Sande M
Published: July 2011

Background

Delay between HIV diagnosis and entry into care may impact not only on the individual prognosis, but hinders interruption of further HIV transmission. Insight into duration and determinants of care-delay and differences between those who do and do not delay are important to further public health policy aimed at reducing ongoing HIV transmission.

Methods

(1). Data from the ATHENA national observational cohort for HIV patients with a first date of care from January 2008 until May 2010 were analysed to assess place, date of initial positive diagnosis and entry date into care. (2). Prospective data collection is set up regionally from consenting patients testing HIV positive at the STI clinics in Amsterdam and Rotterdam. Results from February 2009 until April 2010 for time into care and delay are presented. For this analysis delay of entry into care is defined as a time period of 4 weeks or more between confirmed HIV diagnosis and first consultation at the HIV treatment centre.

Results

(1). At the national level, 28% of all new patients entering care (n=2775) was diagnosed HIV positive at their GP, 25% at an STI clinic, 23% in the hospital, 2% at the pregnancy screening, 4% abroad, 4% other and 14% unknown. Median number of days between HIV diagnosis and entry into care was 19 days (IQR 7–49 days). In 16% of patients time to enter care took over 150 days; those infected by heterosexual contact or injecting drug use were more likely to be in this group. Patients born outside the Netherlands were also more likely to enter care late. 2). From February 2009 until April 2010, 120 participants were included in the study (response 70%). The majority (n=108) were men who have sex with men (MSM). For 78% of participants a date of entry into care was known; median time into care was 8 days (range 0–104 days). Twenty two per cent had not entered care yet of whom 16% had CD4 cell counts below 350. Of participants who were directly referred to an HIV treatment 10% delayed for medical care compared to 45% of participants wanted to make an appointment on their own initiative.

Conclusions

Specific subpopulations such as heterosexuals and ethnic minorities are at risk for entering care late after being diagnosed HIV positive. Results from the prospective study show that direct referral from STI clinic to an HIV treatment centre leads to less delay. Testing of those at risk is not enough to interrupt HIV transmission chains, entry into care needs to be assured as well.
O5-S2.03 Effect of improving the STI services in seven provinces of China
Authors: Gong X D , Jiang J , Su X h , Cao N X , Yue X L
Published: July 2011

Background

The STI services can reduce HIV transmission and have been the important component of HIV control programmes. In China, the STI services remain weak. Under the framework of AIDS control programme of the Global Funds Round 4, we conducted the sub-programme to improve STI services in 21 counties of 7 provinces in China from 2007 to 2009, including one-week training workshops for all STI care providers, two-month field training for key STI clinicians at STD Clinic of National Center for STD Control, STI drug assurance, and quality services offering for STI patients. Annually the effect of STI services was assessed according to the guideline of WHO/UNAIDS in the 21 counties.

Methods

The assessment of STI services was through health facility survey, including three indicators: (1)STI service indicator 1 (SI1) is defined as the per cent of patients with STIs at observed health care facilities who are appropriately diagnosed and treated according to the national guidelines on STI treatment in China; (2) STI service indicator 2 (SI2) is defined as the per cent of patients with STIs who are given advice on condom use and partner notification and referral for HIV testing in term of national standards; (3)Standardised STI service indicator (SSI) means the comprehensive case management including SI1 and SI2. The sample size of STI patients between provider and client interactions observed was 40 per county according to the recommendation of national experts. Data were collected in observations of provider-client interaction at the health-care facilities offering STI services by trained professionals. The software of EpiData3.1 and SPSS 11.5 was used to data entry and analysis.

Results

From 2007 to 2009, the SI1 was 46.16% (397/860) (95% CI 42.83% to 49.49%), 62.94% (603/958) (95% CI 59.88% to 66.00%), 81.96% (686/837) (95%CI 79.35% to 84.57%) on average in 21 counties, respectively, and there was significantly increased trends (χ2is 234.30, p=0.000); the SI2 was 28.32% (243/858) (95%CI 25.31% to 31.33%), 45.04% (431/957) (95% CI 41.89% to 48.19%), 80.33% (678/844) (95% CI 77.65% to 83.01%) on average for these counties, respectively, and there was also significantly increased trends (χ2is 459.37, p=0.000). For overall STI service quality, SSI was 20.98% (180/858) (95% CI 18.26% to 23.70%), 40.02% (383/957) (95% CI 36.92% to 43.12%), 67.26% (563/837) (95% CI 64.08% to 70.44%), respectively in 2007–2009, and there was significantly increased trends (χ2is 370.81, p=0.000). The STI service indicators in rich areas were higher than in poor counties.

Conclusions

The quality of STI services was significantly improved through the Global Funds Round 4 in 21 counties of seven provinces in China, and should be scaled up to other areas in the country.
O1-S03.04 Core groups, antimicrobial resistance and rebound in gonorrhoea
Authors: Chan C , Fisman D , McCabe C
Published: July 2011

Background

Neisseria gonorrhoeae(NG) is a major cause of sexually transmitted infection worldwide. Surveillance data from North America suggest that incidence has increased in recent years, after initially falling in the face of intensified control efforts, as antimicrobial resistance in NG has increased. We evaluated the likely mechanisms behind such rebound using simple compartmental models, and explored the implications of such rebound for disease control practice.

Methods

We evaluated the impact of risk-focussed treatment strategies on long-term gonorrhoea trends using risk-structured susceptible-infectious-susceptible" (SIS) compartmental models that included and excluded the possibility of antibiotic resistance in gonorrhoea transmission and control. We also examined optimal treatment strategies to minimise gonorrhoea rates when more than one antibiotic is available.

Results

Model projections, consistent with previous work, showed that when antibiotic resistance is not possible, strategies that focus on treatment of highest risk individuals (the so-called “core group”), result in collapse of gonorrhoea transmission see Abstract O1-S03.04 figure 1. In contrast, in the presence of antimicrobial resistance, a focus on the core group causes rebound in incidence, with maximal dissemination of antibiotic resistance. When two antibiotics are available for treatment, we found that random assignment of treatment was most effective at delaying rebound in overall rates in the population, while the current strategy, which is to switch first-line treatment when a threshold level of resistance is reached, produced the quickest rebound.

Abstract O1-S03.04 Figure 1

Prevalence over time with risk group-focused treatment strategies.

Conclusions

While previous models have shown that the targeted treatment of core-group individuals is the most effective at lowering rates of gonorrhoea, our model suggests that core group-focused treatment strategies efficiently disseminate antimicrobial resistant strains of NG, with rebound in gonorrhoea rates. This paradox poses a great dilemma to the control and prevention of gonorrhoea, especially when development of new antibiotic classes has lagged in recent years and vaccine development for gonorrhoea still faces many challenges. Our study highlighted the need for focus on non-antimicrobial strategies for the prevention and control of gonorrhoea.
O5-S4.01 Register-based chlamydia screening: does it make a difference if the invitation is sent by GP or by Municipal Health Service?
Authors: van Bergen J E A M , Koekenbier R H , Fennema J S A , Brouwers E E H G , Götz H M , Hoebe C J P A , Op de Coul E L M , Pars L L , van Ravensteijn S M , van den Broek I V F
Published: July 2011

Background

In cervical cancer screening, uptake of screening is approximately 10% higher if a woman is invited by her General Practitioner (GP) compared to invitation by Municipal Public Health Service (PHS). A large register-based selective Chlamydia Screening Programme is implemented in Amsterdam (Netherlands) since 2008 by the PHS. We wanted to evaluate whether response rates in Chlamydia screening where higher if invitational letters are sent by a persons' GP and not by PHS.

Methods

Based on the municipal registers, annually all 140 000 persons in Amsterdam aged 16–29 yr are invited with a postal letter to participate. Further procedures are internet-based: requesting test-packages, obtaining results, even partner-referral, can be realised via the internet and the unique identifier provided in the personal letter. In one part of the city, the Southeast inner-city area, GP-registers of six health centre are matched with the list of invitees extracted from the municipal register. In the invitational letter these matched eligible's are personally addressed by their GP and not by the physician of the PHS. Participation rates from invitees of GP and PHS in the same geographical town area are compared in three screenings-rounds (r 3 not yet fully completed).

Results

In these four town area's in each screening round annually 13 500 persons are invited, of which 35% by the GP and 65% by PHS. In screenings-round 1, the response to invitations by the GP was slightly higher than the response to invitations sent by the PHS in 3 out of 4 neighbourhoods where this was piloted (overall GPs: 16.2% [range: 15.3%–29.1%]; overall PHS: 14.9% [14.4%–21.6%], p=0.023). In round 2 and 3 the difference was not significant (GP vs MHS: r2 10.3%–10.2%; r3 9.5% vs 9.4%). (Abstract O5-S4.01 figure 1).

Abstract O5-S4.01 Figure 1

Participation rate comparing response among GP- and MHS-invitees in 4 town-areas of Amsterdam Southeast.

Conclusions

In the first screening-round uptake was slightly higher among GP-invited, but this effect was lost in subsequent screening-rounds. Inviting universally via the PHS is logistically easier and yields the same response rate.
O1-S04.02 Regional HIV surveillance of youth MSM through multilevel analysis of RDS studies in Latin America
Authors: Jacobson J O , Alonso-Gonzalez M , Ramachandran D , Paz-Bailey G , Balan I , Morales-Miranda S , Guardado M E , Salamanca-Kacic R , Nieto-Gomez A I , Maddaleno M
Published: July 2011

Background

Men who have sex with men (MSM) are the population most affected by HIV in Latin America (LA). Youth MSM (YMSM) are of particular interest given potentially greater levels of risk behaviour and as a barometer of recent epidemic dynamics. Yet single MSM studies lack sufficient sample size to characterise YMSM so that HIV prevalence and variation among YMSM within LA is unknown.

Methods

We developed a multilevel statistical framework to borrow strength across recent (2006–2009) respondent-driven sampling (RDS) studies with similar survey methodologies to permit characterisation of HIV prevalence and risk factors among YMSM in LA and comparisons across cities. Data from participants aged 18–24 years tested for HIV in MSM studies in nine high-population cities in Argentina, Bolivia, Costa Rica, El Salvador and Honduras (N=1410) were pooled. Weights incorporating personal network and population sizes adjusted for selection probability. Logistic, multilevel models identified correlates of HIV infection, including city-level fixed effects and accounted for intraclass correlation within recruitment chains.

Results

HIV prevalence was 4.6% (95% CI: 3.2% to 6.5%) in the pooled sample and varied significantly across cities from 2.7% in Buenos Aires, Argentina to 9.3% in San Pedro Sula, Honduras. Samples varied (p value<0.05) in terms of completion of secondary education (69.6%–100.0%), gay (range 2.5%–77.5%) and bisexual self-identity (18.8%–97.6%), past-year drug use (5.9%–64.8%), condom use at last anal sex (26.6%–72.7%) and other risk behaviours, knowledge of HIV prevention and transmission (26.4%–71.9%) and lifetime HIV testing (28.7%–59.2%). In multivariate analysis, syphilis infection (adjusted OR [AOR]=2.5), aged 23–24 years (vs 18–22) (AOR=2.2), past-year crack/cocaine use (AOR=2.2) and bisexual self-identity (AOR=0.5) were associated with HIV infection. Significant city effects for Salvador, El Salvador and Santa Cruz, Bolivia persisted net of individual-level differences.

Conclusions

Formal comparisons of HIV burden and risk differences among cities can be achieved through multilevel analysis. HIV prevalence, drug and sexual risk behaviours, and low HIV testing among YMSM in LA are considerable and vary substantially within the region. The need for prevention among YMSM in LA is urgent and must address substance abuse, STI and be tailored to local context. Prevention should target younger YMSM as probability of infection rises rapidly with age.
O1-S04.03 Co-infection with sexually transmitted infections among Canadian street-involved youth 2001–2006
Authors: Atwood C V , Fang L , Demers A , Gratrix J , Rossi M , Taylor D , Wright J , Wong T , jayaraman G ,   For the Enhanced Street Youth Surveillance Team
Published: July 2011

Background

Canadian street-involved youth are at greater risk for sexually transmitted infections (STIs), due to their increased vulnerabilities related to age, socioeconomic status, life course factors, and engagement in high risk behaviour such as sex trade. We present a risk factor analysis for those with single and multiple STIs, using the Enhanced Surveillance of Canadian Street Youth (E-SYS) data.

Methods

E-SYS is a cross-sectional surveillance system of street-involved youth (15–24 years). Participants from seven urban centres completed an interviewer-administered questionnaire and were tested for multiple sexually transmitted and blood-borne infections. For this analysis, data were restricted to five infections (HIV, chlamydia, gonorrhoea, syphilis and HSV-2). Data from three cycles (2001–2006) were analysed to determine total number of infections per participant using an iterative tracker. Participants who indicated previous participation were excluded from the analysis to avoid double-representation.

Results

Of those who provided biological specimens (n=3823), 17.0% tested positive for one infection and 3.4% tested positive for two or more infections (Abstract O1-S04.03 table 1). Over half (15 of 28) of HIV-positive individuals were multiply-infected. Risk factors for multiple infections included older age (p=0.0449), being Aboriginal (p=0.0061; particularly females), being HIV infected (p=<0.0001), having a previous history of an STI (p=0.0144), pregnancy (p=0.0079), and reporting prostitution as the primary source of income (p=0.0028).

Abstract O1-S04.03 Table 1

Single and multiple STI in the enhanced street youth surveillance population

ChlamydiaGonorrhoeaSyphilisHSV-2HIVChlamydia268(7.98%)Gonorrhoea42(1.26%)17(2.35%)Syphilis2(0.07%)2(0.07%)3(0.09%)HSV272(2.78%)19(0.74%)4(0.14%)348(12.20%)HIV4(0.15%)0(0.00%)1(0.03%)14(0.50%)13(0.44%)Tested overall33573339319028522951Total # of individuals infected375691044228Prevalence overall11.17%2.07%0.56%15.50%0.95%

* Same-infection crosses represent single infections.

%’s based on individuals tested for both infections.

An individual may be counted more than once if they have more than two infections.

Conclusions

The prevalence of certain STI co-infections (eg, chlamydia and gonorrhoea) is high among street-involved youth and within this population, certain sub-groups may be more vulnerable to these co-infections. Continued efforts are required to promote comprehensive STI testing among street-involved youth and to raise awareness of the potential for multiple infections.
O1-S04.06 Pelvic inflammatory disease occurring between the time of testing and treatment for gonorrhoea and chlamydia
Authors: Risser W , Risser J
Published: July 2011

Background

We conducted a prospective study to confirm our impression that incarcerated adolescents sometimes developed pelvic inflammatory disease (PID) during the brief interval between testing and treatment for gonorrhoeal and chlamydial cervicitis.

Methods

We performed the study at the Harris County Juvenile Detention Center, Texas, where PID in females is relatively common and where the prevalence of gonorrhoea and chlamydia infections is high. At the time of their mandated medical assessment, all incarcerated adolescents submitted first-catch urine samples for chlamydia and gonorrhoea testing. We used Gen-Probe NAAT assays. If at the time of testing a patient had symptoms suggestive of PID, we performed a bimanual pelvic examination and treated those who met the criteria for PID. For the diagnosis of PID, we used the criteria of the US Centers for Disease Control and Prevention: the presence of adnexal or cervical motion or uterine tenderness. The pelvic examinations were performed by one of three experienced physicians. For the patients who did not have PID at the time of testing, we re-assessed them when we learnt that their urine test was positive. The tests were run in batches by the city health department, so that a variable length of time elapsed between the day of testing and the day that we received test results. At re-assessment, patients received a PID diagnosis if they had lower abdominal pain and met the PID diagnostic criteria on bimanual pelvic examination.

Results

We evaluated 99 subjects between 29 March 2010 and 27 December 2010. Their mean age was 15.8 (SD 1.1) years. Their race/ethnicity was 43% black, 32% Hispanic, and 25% white; 74% had chlamydia, 14% gonorrhoea, and 12% both. The interval between testing and treatment ranged from 2 to 17 days; the mean (SD) was 7.5 (2.9) days. During this interval, 13 of 99 (13%) developed lower abdominal pain and had bimanual pelvic examination findings that supported the diagnosis of PID. Of these 13, 10 (77%) had chlamydia, 2 (15%) had gonorrhoea, and 1 (8%) had both infections. Time from initial urine testing to treatment for PID ranged from 7 to 15 days.

Conclusion

In incarcerated adolescents infected with gonorrhoea and/or chlamydia, a surprisingly large proportion (13%) developed PID during the brief period between testing and treatment.
O1-S05.02 Biological evidence of semen exposure is associated with incidentBacterial vaginosis
Authors: Gallo M , Warner L , King C , Sobel J , Rompalo A , Cu-Uvin S , Klein R , Schoenbaum E , Jamieson D
Published: July 2011

Objectives

(1) To identify correlates of incidentBacterial vaginosis(BV) among high-risk women and (2) to identify predictors of discordance between self-reported lack of semen exposure in the past 6 months and the detection of spermatozoa on Gram stain, which provides biological evidence of recent exposure.

Methods

Analyses were based on among 871 HIV-infected and 439 HIV-uninfected women participating in HIV Epidemiology Research Study (HERS) which was conducted in 4 sites in the US Participants completed study visits conducted at baseline and at 6-month intervals thereafter. We conducted both cohort and case-crossover analyses, stratified by HIV infection status, to evaluate potential correlates of incident BV. We also used logistic regression to identify predictors of discordance between self-reported lack of exposure to semen and the detection of spermatozoa on Gram stain.

Results

BV incidence was 21% among HIV-infected women and 19% among HIV-uninfected women. We found fewer correlates of incident BV when assessed with a case-crossover design than with a cohort design. Reporting frequent coitus (regardless of consistency of condom use) was correlated with incident BV in the cohort analyses but not in the case-crossover analyses. The sole correlate that emerged in both the cohort and case-crossover analyses among HIV-infected and -uninfected women was the detection of spermatozoa on Gram stain. Seven factors were associated with discordance between self-reported semen exposure and spermatozoa detection in the multivariable analysis. Discordance differed by study site and race/ethnicity and was more common among younger women. The following infections or conditions also were predictive of discordance: HIV (adjusted OR [aOR], 2.8; 95% CI, 1.7% to 4.6%), BV (aOR, 1.9; 95% CI, 1.5% to 2.5%), and human papillomavirus (aOR, 1.3; 95% CI, 1.0% to 1.8%). Finally, reporting current injection drug use (aOR, 0.6; 95% CI, 0.4% to 0.9%) was inversely related to discordance.

Conclusions

The inconsistent association between condom use and BV found in prior studies could be the result of participant reporting bias. The present study found evidence of a relationship between semen exposure and incident BV. Also, given the number and range of correlates of discordance between self-reported and biological evidence of semen exposure, inaccuracies in the reporting of sexual behaviours cannot be assumed to be distributed randomly across a study population.
O1-S01.03 High yield in reinfections during a chlamydia screening programme when automatically sending testkits after 6 months to previously infected
Authors: Götz H M , Hoebe C J P A , van Bergen J E A M , Brouwers E E H G , Op de Coul E L M , Fennema J S A , Koekenbier R H , Pars L L , van Ravesteijn S M , van den Broek I V F
Published: July 2011

Background

Reinfections remain challenging in the control ofChlamydia trachomatis(Ct). In a systematic internet-based Ct Screening programme (CSI) in the Netherlands, all Ct-positive participants automatically received a test kit after 6 months to facilitate discovery of reinfections. Determinants for reinfection for two screening rounds, treatment and partner notification are discussed.

Methods

CSI-home-based testkits can be requested online after register based postal invitation. Infected participants get a referral letter for their health provider to get treatment for themselves and their current partner; expartners can be alerted by the participant and request a test kit via the website. Participants fill in a questionnaire on sexual behaviour voluntarily. Ct-positives answer questions about treatment and partner notification 10 days after checking their results. Infected participants who do not check their result online receive it by postal letter. After 6 months retest kits are automatically sent to previously infected participants.

Results

Overall, 3185 participants (4.1%) tested positive; 7% of Ct-positives did not check their result online and received a postal letter. The majority (86%) of Ct-positive participants who answered the treatment questionnaire (response 43%) was treated within 2 weeks after checking their result online; 80% of those with a current relationship reported their partner had also been treated and 16% of those with past relationships notified ex-partners via the website. One third of the ex-partners participated, 28% of whom were Ct-positive. After 6 months, 3055 participants received a retest kit and 66% responded. The reinfection rate was 8.8%. Results of the questionnaire revealed 75% of retest-positives had been treated for the initial infection and 70% had had their partner treated, while these proportions were 87% and 80% among retest-negatives. At higher risk for reinfections were young people (<20 years 17%), specific ethnic minorities (Netherlands Antillean 16%, Turkish 17%, sub-Sahara African 18%), persons living in Rotterdam (11 vs 8% Amsterdam 4% Limburg), and in high-risk areas (14%).

Conclusions

The uptake of retesting was successful counting two third with automatically sent testkits 6 months after screening. Reinfection rates were high, especially among known risk-groups. Questionnaire results show that follow-up of (partner) treatment after Chlamydia infections could be improved.
O1-S06.06 Patterns and trends in concurrency and polygamy in rural Zimbabwe, 1998–2008
Authors: Takavarasha F , Gregson S , Eaton J , Schumacher C , Mushati P , Garnett G , Nyamukapa C
Published: July 2011

Background

It has been suggested that the decline in HIV prevalence in Zimbabwe from the late 1990s may be partly due to reductions in sexual concurrency but little is known about levels and trends in the different forms of concurrency or their association with HIV risk.

Methods

We use data from four rounds (1998–2000, 2001–03, 2003–05, 2006–08) of a large longitudinal population-based HIV survey to investigate patterns of non-spousal (two or more current sexual partners, at least one of whom is not a spouse) and spousal (multiple spouses but currently no extra-marital sexual partners) concurrency, and associations with prevalent HIV infection in rural east Zimbabwe.

Results

15.4% (95% CI 14.4% to 16.5%) of men (17–54 yrs, N=4327) and 1.9% (1.5% to 2.3%) of women (15–44 yrs, N=5148) reported concurrent sexual partners at baseline. 11.7% (10.8% to 12.7%) and 3.7% (3.2% to 4.3%) of men reported non-spousal and spousal concurrency, respectively. Non-spousal concurrency was most common in single (16%) and divorced/widowed (11%) men but was also reported by married men with single (6.5%) and multiple (4%) spouses (Abstract O1-S06.06 figure 1). HIV prevalence is similar in men with (19.2%) and without (19.5%) concurrent partners but is higher in those with concurrent partners after controlling for age (age-adj. OR (aOR), 1.37; p=0.02). However, after excluding non-sexually experienced men, this difference was not statistically significant (aOR, 1.27, p=0.08). Among all men, HIV prevalence was higher for those with non-spousal concurrency (aOR, 1.38; p=0.015) but not for those with spousal concurrency (aOR, 1.26; p=0.2). For women, concurrency (all non-spousal) was 1.9% (95% CI 1.2% to 2.7%) in single women, 0.4% (0.2% to 0.7%) in married women, and 5.4% (4.1% to 7.0%) in divorced/widowed women. HIV prevalence was higher in women with concurrent partners than in those without (55.7% vs 25.4%; aOR, 3.26, 2.08 to 5.11) even after excluding women who had not started sex (aOR, 2.83; p<0.001). For males, non-spousal concurrency fell from 11.7% (95% CI 10.8% to 12.7%) in 1998–2000 to 6.1% (5.3% to 7.0%) in 2001–2003 and 4.3% (3.7% to 5.0%) in 2006–2008; prevalence of spousal concurrency fell from 3.7% (3.2% to 4.3%) to 2.6% (2.0% to 3.2%) to 1.3% (1.0% to 1.7%) over the same period. For females, concurrency declined from 1.7% (1.4% to 2.1%) in 1998–2000 to 1.0% (0.7% to 1.3%) in 2001–2003 and 0.5% (0.3% to 0.7%) in 2006–2008.

Abstract O1-S06.06 Figure 1

Prevalence of non-spousal concurrency by marital status, Men, 17–54 years.

Conclusion

A 2/3rds reduction in (mainly non-spousal) concurrency may have contributed to HIV decline in east Zimbabwe.
O1-S07.03 Prevalence and correlates of rectal chlamydia and gonorrhoea among female STD clinic clients
Authors: Javanbakht M , Guerry S , Stirland A , Gorbach P , Kerndt P
Published: July 2011

Background

The prevalence and correlates of rectal sexually transmitted infections (STI) are well described among men who report receptive anal intercourse (AI). However, very little is known about the epidemiology of rectal STIs among women.

Methods

We conducted a cross-sectional study of women attending twelve public STD clinics in Los Angeles County, California. Women were eligible for inclusion in this study if they reported AI in the previous 90 days, were tested for rectal chlamydia (CT) and gonorrhoea (GC), and were seen between January 2008 and December 2009. Data collected included demographics, types of sexual contact, substance use, other risk behaviours, and STI results. Results Among the 716 females included in this analysis, the median age was 28 years (range 14–60), 40% were Hispanic, 37% African American, and 15% White. The prevalence of CT and GC by anatomic site was: 11.8% (n=83) urogenital CT, 14.2% (n=100) rectal CT, 2.7% (n=19) urogenital GC, and 3.0% (n=21) rectal GC. Among positives, 27% of CT cases and 27% of GC cases had rectal only infections. Among women =25 years the prevalence of rectal infections was higher among those incarcerated in the past year (39.4% vs 22.1%; p value=0.03) and those who reported sex with an injection drug user (50.0% vs 23.3%; p value=0.05). Among women >25 years the prevalence of rectal infections was higher among those with longer term sex partners (ie, >90 days; 12.6% vs 5.9%; p value=0.03), and those who reported substance use (14.8% vs 8.3%; p value=0.04). While the number of women with a rectal-only infections (ie, no urogenital infection; n=33) was small, similar trends were observed. After controlling for age and race/ethnicity, among women ≥25 years those incarcerated in the previous year were more likely to have a rectal infection (adjusted OR [AOR]=2.55; 95% CI 1.14% to 5.71%). Among women >25 years, after controlling for race/ethnicity and age, those who reported substance use were more likely to have a rectal infection (AOR=2.28; 95% CI 1.14% to 4.55%) while those reporting new sex partners were less likely to have a rectal infection (AOR=0.38; 95% CI 0.16% to 0.88%).

Conclusion

These findings highlight that the prevalence of rectal Chlamydia and gonorrhoea among women is similar to that of urogenital infections and a relatively large number of infections would be missed in the absence of rectal testing. Factors associated with rectal infections may differ by age.
O1-S07.06 Lymphogranuloma venereum in the UK: is there evidence for rectal to rectal transmission? Results of a multicenter case control study
Authors: Ward H , Macdonald N , Ronn M , Dean G , Pallawela S , Sullivan A , White J , Smith A , French P , Ison C
Published: July 2011

Background

The outbreak of lymphogranuloma venereum (LGV) in men who have sex with men (MSM) in the UK is ongoing, with over 500 cases diagnosed in 2010 alone. Control efforts have been limited by a lack of understanding of the epidemiology, particularly transmission. The majority of cases are rectal with small numbers of urogenital or pharyngeal infections. No significant reservoir of asymptomatic or undiagnosed infection has been identified. The possibility of rectal to rectal transmission is suggested by studies showing an association of LGV with fisting, use of sex toys and enemas. We aim to identify risk factors to better understand transmission.

Methods

A case control study of LGV in six UK clinics from 2009 to the end of 2010. Confirmed cases of LGV in MSM were compared with symptomatic and asymptomatic controls. Clinical and behavioural data were collected using a web-based computer-assisted self-interview and linked to web-based clinical report forms (CRF). We used a two-stage process to construct multivariable logistic regression models in order to control for confounding and interaction between risk factors.

Results

We have recruited 99 cases, 86 symptomatic and 88 asymptomatic controls. There were 94 rectal cases (including one who also had pharyngeal LGV), two urethral and one genital ulcer (two CRFs outstanding). In univariate analysis, LGV was significantly associated with many factors; the strongest associations were with HIV infection, specific anal sex practices (including unprotected receptive and insertive intercourse, rimming, use of toys, fisting, douching), meeting partners through the internet or in a backroom, and use of stimulant drugs. In final multivariable logistic regression models HIV-positivity, fisting, younger age at first clinic attendance and recent use of methamphetamine remained significant predictors of LGV when compared to asymptomatic controls. Compared to symptomatic controls, unprotected insertive anal intercourse was the only significant risk factor in the final model.

Conclusions

Men reporting both insertive and receptive anal sex practices are at highest risk of LGV. Rectal to rectal transmission may be occurring with the organism being transferred via toys, fingers and penises; transient colonisation of the urethra may explain the low incidence of urethral LGV. Improved hygiene measures may have an important role in reducing transmission.
O1-S09.06 Assessing the impact of a FSW targeted HIV intervention programme on incidence and prevalence in Cotonou, Benin
Authors: Williams J , Boily M C , Lowndes C , Camden S , Demers E , Minani I , Zannou M , Anagonou S , Labbé A C , Alary M
Published: July 2011

Background

From 1993 to 2005 female sex workers (FSW) were the focus of a HIV intervention in Cotonou where most local FSW originated from three neighbouring countries. Intervention impact was assessed using a HIV transmission model parameterised and fitted to empirical data within a Bayesian framework, to compare predicted epidemic outcomes with and without the intervention.

Methods

An age-structured model was developed of HIV transmission in Cotonou, coupled with a non-age structured Gc model. The model included realistic demography, heterogeneous sexual risk groups including local and migrant FSW to and from Cotonou, clients and general population (GP); each FSW nationality was parameterised separately. Programs of condom use and STI treatment modelled reflected levels of uptake pre- and post-intervention. Plausible parameter ranges based on local multiple survey data from different risk groups and time points and literature reviews (ie, prior parameter distribution) were sampled repeatedly by Latin hypercube sampling. Model predictions from parameter sets matching (ie, fitting") observed HIV prevalence data from Cotonou (FSW by nationality, their clients, and broad GP age-bands) at different time points were accepted as good fits (ie, posterior parameter distribution (PPD)) and used to estimate impact (95% credibility interval (CrI)) by comparing HIV incidence predicted based on the PPD with that using the same parameter values except for the assumption that condom use and STI treatment remained at 1993 levels (control group/counterfactual).

Results

From 100 000 parameter combinations tested, 18 produced results that agreed with observed HIV prevalences in FSW (Abstract O1-S09.06 figure 1) and other groups over time. Results with no intervention suggest a peak HIV prevalence in FSW 10–12 years later than observed and at around 75%, compared with the observed level of just over 53% (corresponding GP prevalences were 9.6% & 6.7% respectively). Results also suggest that about 33%(CrI: 28, 37) and 25%(CrI: 17, 33) potential HIV cases may have been averted in Cotonou FSW and GP respectively, by increased condom use and STI services after the start of the intervention.

Abstract O1-S09.06 Figure 1

Conclusions

Coupled with observed HIV trends, the analysis indicates that FSW targeted intervention was effective in curtailing the HIV epidemic in Cotonou-based FSW despite high turnover of foreign FSW. There was also substantial impact in the general population by impeding onward transmission to clients/boy-friends.
O1-S10.03 Lymphogranuloma venereum, HIV and high-risk behaviour: findings from LGV enhanced surveillance and mathematical modelling
Authors: Ronn M , Garnett G , Hughes G , Ison C , Simms I , Alexander S , Ward H
Published: July 2011

Background

Lymphogranuloma venereum (LGV) re-emerged in industrialised countries in the early 2000s and most transmission is assumed to occur among high-risk HIV-positive men who have sex with men (MSM). As the epidemic matures, we would expect to see declining HIV prevalence among cases as the transmission moves outside the initial core groups, however LGV cases continue to present with high levels of HIV-positivity. We have previously conducted a systematic review and a meta-analysis of literature published on LGV and found an eightfold greater likelihood of HIV-positivity among LGV cases when compared to controls with non-LGV chlamydia. In this study we investigate the role of high-risk behaviour, serosorting and differences in transmission probability as contributing factors to the persistent association between HIV and LGV.

Methods

Data from LGV Enhanced Surveillance in the UK were used to investigate the relationship between HIV-positivity and LGV acquisition by setting HIV-positivity as the outcome in logistic regression. A simple deterministic compartmental model was developed, stratified by HIV-status and risk behaviour, to simulate the spread of infection among MSM in a large metropolitan population. Assortative mixing for HIV status and high-risk behaviour were controlled independently of each other see Abstract O1-S10.03 figure 1.

Abstract O1-S10.03 Figure 1

Flowchart illustrating the model structure.

Results

Up to date approximately 81% of the 1500 confirmed LGV cases have had surveillance forms returned with above 70% HIV-prevalence among cases over time. HIV-positive LGV cases were more likely to report unprotected anal intercourse and greater number of partners than HIV-negative LGV cases in surveillance data. The mathematical model indicates that extreme levels of serosorting would be needed to explain the high prevalence of HIV in the presence of high-risk HIV-negative group. Increase in the number of HIV-positive individuals, higher transmission probability in HIV-positive and serosorting together were better able to reproduce the strong association between HIV and LGV.

Conclusions

Differential acquisition of LGV occurs according to HIV status. LGV acquisition among HIV-positives may be due to serosorting together with an increased transmission probability due to reduced condom use and sexual practices, and potential biological susceptibility. Findings suggest that HIV-positive MSM need targeted health promotion in view of their different risk behaviours.
O1-S01.06 Estimation of the burden of disease and costs of genitalChlamydia trachomatisinfection in Canada
Authors: Tuite A , Fisman D
Published: July 2011

Background

Chlamydia trachomatis(CT) is the most common notifiable infectious disease in Canada. Rates of infection have been increasing since the mid-1990s, suggesting that alternate control strategies may be required. Given that the current cost of Chlamydia infections in Canada is unknown, we sought to estimate the burden of CT in the Canadian population, to provide a foundation on which health economic analyses of competing Chlamydia control strategies can be constructed.

Methods

We used an age- and sex-structured mathematical model parameterised to reproduce trends in CT prevalence in the Canadian population aged 10 to 39 years. Model parameters were derived from epidemiologic studies and by model calibration. We incorporated data on changing test patterns of asymptomatically infected individuals over time. Costs were identified, measured, and valued using a modified societal perspective and were converted to 2009 Canadian dollars. The main outcome measures were the current net cost and burden of illness attributable to CT infection.

Results

The model reproduced trends in CT prevalence observed for the time period between 1991 and 2008. Under base case model assumptions, there appeared to be a trend of increasing detection of CT cases (due to increases in screening and subsequent detection of asymptomatic cases), despite an underlying decrease in actual CT infections in the population. The total estimated costs associated with CT infection over this time period were over $1.0 billion, or $56.4 million per year. The costs of screening and treatment of asymptomatic infections as a proportion of total CT costs were estimated to have increased over time, while the costs of long-term sequelae associated with untreated infections declined the same period.

Conclusions

Despite increases in screening over time, the total economic burden associated with CT in Canada remains high; however, the projections of our model suggest that these increases in screening and the subsequent detection of asymptomatic infections may be reducing the costs associated with the treatment downstream sequelae of untreated infections. Further investigation of trends in chlamydia-associated complications is required to better understand the impact of screening on CT incidence in Canada.
O1-S10.06 HIV/STI prevalence among men who have sex with men in 4 cities, China and associated risk factors for HIV infection
Authors: Chen X , Jiang N , Wang B
Published: July 2011

Objectives

The data on STIs control and HIV prevention is limited among MSM population. To examine STIs control strategies for HIV prevention in a community-based cohort of HIV-negative MSM, community intervention trail was conducted between 2009 and 2011. This report mainly discussed baseline survey results.

Methods

This study was conducted in MSM community of four mid-sized cities from Jul. to Sep. 2009. All participants were recruited through venue-based recruitment, complemented by peer referral using snowball method, Questionnaire were completed in STD clinics or VCT centers. Blood samples were collected for HIV, syphilis and HSV-2 tests, and urine sample for CT/NG PCR tests.

Results

35.3% participants self-identified as homosexual and 44.7% bisexual. The most popular way to seek male sexual partners was internet (38.4%). 15.9% of participants had provided or acquired sex services with male, while 19.1% of respondents reported unprotected anal intercourse (UAI) in the last sex services. 3.8% of participants had experienced sadism & masochism(SM). In past 6 months, 80.8% of participants had anal sex with man and 29.0% reported UAI during the last intercourse. 38.5% of participants reported having had sex with woman and only 45.2% of those reported using condom during the last intercourse with woman. 18.0% of participants involved in commercial sex services had taken drugs such as methamphetamine, Ketamine and MDMA.10.6% of participants was HIV infection. 34.4% of participants is TP-ELISA positive results indicated a history of syphilis infection, and 20.9% were both positive results of ELISA and TRUST indicated active syphilis. 3.0% of participants were tested as NG infection, 6.8% was CT infected, and 16.2% were HSV-2 infected. Significant factors associated with HIV infection were self-reported STD infection history [AOR=2.1, 95% CI: 1.29% to 4.26%], syphilis infection [AOR=2.70, 95% CI: 1.81% to 4.04%], and HSV-2 infection [AOR=3.07, 95% CI: 2.09% to 4.50%].

Conclusions

MSM have been potential bridge-population for HIV/STIs from most-at-risk population to general population. Intervention activities should target the internet, sexual social networks, and certain subpopulations such as those taking drugs in commercial sex services or infected with STIs. Friendly and high-quality STIs service should reach to MSM who do not attend STD clinics. Campaigns are urgent not only to boost individual condom use but also to create culture for condom use in MSM community.
O1-S11.01 Time evolution of the fraction of new HIV infections due to primary infection among high risk groups in southern India
Authors: Pickles M , Boily M C , Vickerman P , Ramesh B M , Washington R , Deering K , Verma S , Blanchard J , Moses S , Alary M
Published: July 2011

Background

HIV infectivity is considerably higher during primary infection (PI: first few months after infection). PI is believed to be an important biological driver of HIV transmission at the population level, which has implication for prevention. We aimed to estimate the contribution of PI to HIV spread among high-risk groups in southern India.

Methods

We used incidence predictions from a bespoke dynamical model of HIV transmission among FSW/clients parameterised and fitted to district-specific behavioural data and HIV/STI prevalence estimates, within a Bayesian framework. Multiple rounds of cross-sectional survey data from among FSW/clients of Mysore and Belgaum, carried out as part of the evaluation of Avahan, the India AIDS initiative, were used to inform plausible parameter ranges and estimate HIV prevalence. Assumed risk of HIV infection (RRHIV/PI) during PI was elevated by 4.5- to 19-fold compared to asymptomatic infections (based on systematic review) and lasted for 3 to 6 months. The annual fraction of new HIV infections (AF) due to primary infection was estimated over time from the 196 and 796 posterior parameter sets fitting Mysore and Belgaum data, respectively.

Results

The median AF (overall: clients+FSW) declined from 57.3% (min=34, max=82)% in 1987 (assumed start of epidemic) to 49% (29,70)% in 2000, 43.7% (25,65)% in 2004, 23.8%/24.3% (10/10, 42/43)% in 2010/2025 for Mysore (Abstract O1-S11.01 figure 1). Similar AF estimates were obtained in Belgaum and for FSWs and clients separately in both districts. The univariate association between AF and RRHIV/PI declined slightly over time (Abstract O1-S11.01 figure 1). In multivariate regression analysis, RRHIV/PI (slope=0.027), duration of the whole infectiousness period (slope=−0.014) and duration of primary infection (slope=0.587) were significantly associated with AF early in the epidemic (1988) (R2=0.833, p value<0.001). However, the AF in 2025 was also associated with number of years selling sex by street-based FSW (slope=−0.020, p value=0.042) and number of years buying sex by high-activity clients (slope=−0.004, p value=0.055) (R2=0.684).

Abstract O1-S11.01 Figure 1

FSW and clients combined Mysore.

Conclusions

The role of primary infection decreased as the HIV epidemic matured but could still account for a large fraction of new infections, especially if RRHIV/PI is above 10. Early on, its contribution depended on parameters of primary infections. Later on, its contribution also depended on the renewal of high-risk susceptible population, which fuels HIV incidence.