bluuebunny/crossref_metadata_2025_split huggingface dataset:
O1-S05.05 Association betweenTrichomonas vaginalisand vaginal bacterial community composition among asymptomatic reproductive-age women in the USA
Authors: Brotman R , Jones L L , Sakamoto J , Gajer P , Ault K , Peralta L , Forney L , Abdo Z , Ravel J 
Published: July 2011

BackgroundVaginal bacterial communities are thought to prevent infection by sexually transmitted organisms. Prior work demonstrated that the vaginal microbiota of reproductive-age women in the US cluster into five groups of bacterial communities; four dominated byLactobacillus spp. (L iners, L crispatus, L gasseri, L jensenii), and one lacking significant numbers of lactobacilli and characterised by higher proportions of strictly anaerobic organisms (termed group IV). We sought to compare the vaginal microbiota ofT vaginalis-positive andT vaginalis-negative women using cultivation-independent methods. To our knowledge, this is the first analysis of the relationship betweenT vaginalisand vaginal bacterial communities characterised by molecular methodologies.MethodsSelf-collected vaginal swabs were obtained cross-sectionally from 396 asymptomatic US women equally representing four ethnic/racial groups. Screening for the presence ofT vaginaliswas performed using PCR targeting the 18S rRNA and ß-tubulin genes. Vaginal bacterial composition was characterised by pyrosequencing of barcoded 16S rRNA genes. The relationship between vaginal microbiota andT vaginaliswas evaluated by Fisher's exact testing and logistic regression.ResultsOf the 11T vaginalis-positive cases, 8 (72%) were classified to the low-Lactobacillus group IV, 2 (18%) and 1 (9%) with communities dominated byL inersandL crispatus, respectively (p value: 0.056). Group IV was associated with an eightfold increased odds of detectingT vaginaliscompared to women with communities dominated byL crispatus(OR: 8.26, 95% CI: 1.07% to 372.65%, p value: 0.04). Other than the major bacteria dominating each cluster, none of the other observed taxa showed significant association withT vaginalis-positivity although this may reflect few observed cases rather than lack of a true association. Ten (91%) of theT vaginaliscases self-reported Black ethnicity and 1 (9%) reported Asian, (p value: 0.00002).ConclusionMolecular analyses revealed that vaginal microbiota with low proportions of lactobacilli were significantly associated with presence ofT vaginalis. Longitudinal studies are needed to identify the causal nature of the relationship between vaginal bacterial communities and STI risk.
O1-S06.03 Pre-exposure prophylaxis for HIV prevention
Authors: Cremin I , Hallett T , Dybul M , Piot P , Garnett G 
Published: July 2011

BackgroundTwo randomised controlled trials have recently provided evidence for the efficacy of Pre-Exposure Prophylaxis (PrEP), whereby uninfected individuals use antiretrovirals—either orally or topically—for the prevention of sexual acquisition of HIV. However, the potential population-level impact of a PrEP intervention remains uncertain.MethodsA population-based deterministic mathematical model was developed to investigate the impact of a PrEP intervention in Cotonou, Benin (1.7% adult prevalence in 2006) and Kisumu, Kenya (13.9% adult prevalence in 2008). It was assumed that PrEP has high intrinsic efficacy (90% reduction in acquisition per PrEP protected sex act) but its effectiveness is reduced by imperfect adherence (75% of sex acts are protected for good adherers (40% of PrEP users) and 30% of sex acts are protected for poor adherers (60% of PrEP users)). The impact of prioritising a fixed amount of PrEP with respect to behavioural risk was investigated, whereby 10% of the population received PrEP in each scenario.ResultsIn the absence of prioritisation of PrEP, an estimated 2.12% and 5.44% of infections would be averted over 10 years in Cotonou and Kisumu, respectively. However, the population-level epidemiological impact of a PrEP intervention can be substantially increased by prioritising to key populations most at risk of infection (Abstract O1-S06.03 figure 1). Percentage of infections averted over 10 years with respect to different levels of prioritisation by behavioural risk, in Cotonou, Benin and Kisumu, Kenya. The efficiency of increased prioritisation by behavioural risk is greater in Cotonou, as the HIV epidemic is more focussed within identifiable at-risk groups. However, the overall epidemiological impact of the PrEP intervention is greater in Kisumu, which has higher HIV incidence than Cotonou. Assuming an estimated cost range for PrEP of $160–$240 per-person per-year, the estimated cost per infection averted in Kisumu, Kenya, ranges from $13,578 to $20,368, if 50% of high risk individuals receive PrEP and the remaining PrEP is distributed among low and medium risk individuals. These costs should be considered in light of future averted costs of ART provision.Abstract O1-S06.03 Figure 1Percentage of infections averted over 10 years with respect to different levels of prioritisation by behavioural risk, in Cotonou, Benin and Kisumu, Kenya.ConclusionsAn effective PrEP intervention could reduce the incidence of HIV transmission in generalised HIV epidemics. Considerable gains in impact, and therefore cost-effectiveness, can be achieved if PrEP is prioritised for those at highest risk of acquisition. Epidemiological context plays an important role in influencing the potential population-level impact of a PrEP intervention.
O1-S01.04 Suboptimal repeat testing of women with positive chlamydia tests in the USA, 2008–2010
Authors: Hoover K , Tao G , Body B , Nye M , Kent C 
Published: July 2011

BackgroundWomen treated for chlamydia have a high prevalence of infection several months later, likely caused by reinfection from an untreated or new infected sex partner. To prevent potential adverse outcomes of chlamydia, US guidelines recommend repeat testing 3 months after treatment, regardless of partner treatment. If retesting at 3 months is not possible, women should be retested at their next clinical encounter within 12 months. A chlamydia test-of-cure is also recommended for all infected pregnant women 3–4 weeks after treatment. We assessed adherence to retesting guidelines using data from a US laboratory corporation that has a large share of the US market.MethodsAmong tests performed from June 2008 to May 2010, we estimated the percentage of women who were retested ≥3 weeks later by test result, age and pregnancy status. We also estimated the positivity rate among repeat chlamydia tests and the mean time between an initial test and the first repeat test. We assumed that for each woman in the database all chlamydia tests during the study period were performed by this laboratory corporation.ResultsAmong 2.90 million chlamydia tests performed in 1.77 million women, 4.0% (114 963) were positive. Among the 1.77 million women with tests, 1.34 million (75.7%) had only a single test and 0.43 million (24.3%) had at least one repeat test. If an initial test was positive, 48.6% were retested compared to 23.5% if the initial test was negative (p<0.01); a repeat test was more likely to be positive in women with an initial positive test (13.3%) than a negative one (3.3%) (p<0.01). The mean time interval between the initial and repeat test was shorter if the initial test was positive (117 days) than negative (149 days). Women aged 15–24 years with a positive test had a lower retesting rate than those aged 25–34 years (46.8% vs 53.3%). The percentage of women with a positive test who were retested differed significantly by pregnancy status (60.0% pregnant vs 44.2% nonpregnant), and pregnant women had a repeat test within 93 days compared to 125 days in nonpregnant women.ConclusionsThese data from a large laboratory corporation provide insight into chlamydia testing practices among women in the USA, and suggest suboptimal adherence to retesting recommendations for both pregnant and nonpregnant women. These data can be useful to monitor the effectiveness of interventions to improve follow-up testing of women with chlamydia.
O1-S08.05 Recent trends in STIs and HIV among female sex workers and their clients in India: results from repeated cross-sectional surveys
Authors: Adhikary R , Ramanathan S , Gautam A , Goswami P , Ramakrishnan L , Kallam S , Mainkar M M , Brahmam G N V , Subramanaian T , Paranjape R S 
Published: July 2011

BackgroundHIV transmission in India is concentrated among high-risk groups. Female sex workers (FSWs) and Clients of FSWs are the most vulnerable groups at risk for HIV. This paper presents the prevalence of sexually transmitted infections (STIs) and HIV among FSWs and their clients in the states of Andhra Pradesh (AP), Tamil Nadu (TN) and Maharashtra (MH) from repeated, cross-sectional, bio-behavioural surveys.MethodsData from two rounds of Integrated Behavioural and Biological Assessments conducted in 2005 (R1) and 2009 (R2) among 15 632 FSWs (R1-7828, R2-7804) and 9624 clients of FSWs (R1-4821, R2-4803) were analysed to observe the changes in STI and HIV prevalence among each group. Respondents' behaviour was assessed and blood and urine samples were collected to test for STIs [Chlamydia trachomatis(CT),Neisseria gonorrhoeae(NG), syphilis and HIV]. Analysis at both the aggregate and state level was done. Adjusted ORs were obtained by including all socio-demographic variables associated with rounds of survey in multivariate models.ResultsAt the aggregate level, among FSWs, prevalence of syphilis declined from 10.8% in R1 to 5.0% in R2 (AOR 0.39, p=0.001) and no significant change was observed in prevalence of HIV, NG or CT. Among FSW clients, STI prevalence was low in R1 (syphilis 4.7%, NG 0.4% and CT 2.4%) and no significant change was observed in R2. The state-wide trend shows that for FSWs in AP, a significant decline occurred in prevalence of both HIV (AOR 0.68, p<0.01) and syphilis (AOR 0.39, p<0.001) whereas in TN, only syphilis prevalence declined (AOR 0.20, p<0.001). The trend in MH differs from the other two states. In MH, prevalence of bacterial STIs (syphilis, NG and CT) declined significantly whereas HIV prevalence increased significantly (AOR 1.29, p=0.04). Among FSW clients, STI prevalence was low in MH (syphilis 4.3%, NG 0.7%, and CT 4.2%) and TN (syphilis 4.1%, NG 0.0%, and CT 0.8%) in R1 and remained unchanged in R2. However, a significant decline occurred in HIV prevalence in both states [MH: AOR-0.25, p=0.002; TN: AOR-2.3, p<0.05]. In AP, only prevalence of syphilis (AOR 0.18, p<0.001) declined and no change was observed in other STIs.ConclusionThe prevalence of syphilis declined among both FSWs and their clients in all three states whereas no change was seen in other bacterial STI prevalence (NG or CT). Among FSW clients in MH and TN, STI prevalence remained unaltered. Tailored and sustained programmatic efforts are needed to address the disparity in prevalence of STIs and HIV in the three states.
O1-S02.01 Epidemiology of, and behavioural risk factors for, sexually transmitted human papilloma virus infection in a sample of the British Population
Authors: Mercer C H , Johnson A M , de Silva N , Beddows S , Desai S , Howell-Jones R , Carder C , Sonnenberg P , Lowndes C M , Soldan K 
Published: July 2011

BackgroundPersistent infection with high-risk sexually transmitted human papilloma viruses (HR-HPV) can lead to development of cervical and other cancers while low-risk types (LR-HPV) may cause genital warts, the most commonly-diagnosed viral STI in the UK. An HPV immunisation programme, using the bivalent vaccine protecting against types 16 and 18, was introduced in the UK in 2008. The frequency of HPV types is important baseline information against which to monitor the direct and indirect effects of vaccination. Here we examine the proportion of the population with detectable infection with HPV in urine collected in 1999–2001 for the National Survey of Sexual Attitudes and Lifestyles (Natsal-2) and the relationship with demographic and behavioural variables.MethodsNatsal-2 was a probability sample survey of men and women aged 16–44 resident in Britain involving computer-assisted personal interviewing. Half of all sexually-experienced respondents aged 18–44 were invited to provide a urine sample. 3436 samples were tested using an in-house Luminex-based HPV genotyping system.ResultsHPV 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's samples and 9.6% (95% CI 8.0% to 11.6%) of men's. Vaccine preventable types 16 and/or 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 and/or 11 in 4.7% (95% CI 1.8% to 3.3%) of women and 2.2% (95% CI 1.5% to 3.1%) of men. 4.1% (95% CI 3.1% to 5.2%) of women had HPV 16 and/or 18 without any other HR-HPV. In multivariate analysis, HR-HPV was associated with number of new partners, in women with younger age, single status, and partner concurrency, and in men with number of unprotected partnerships and age at first intercourse.ConclusionThis is the first population-based probability sample study of the distribution of sexually transmissible HPV types in Britain. It is also the first to undertake a detailed analysis of relationships with demographic and behavioural variables and to include men. HPV DNA was detectable in urine of a high proportion of the sexually active British population; the lower prevalence in males reflected lower detection sensitivity for HPV in urine from males. In both genders HPV was strongly associated with sexual risk behaviour.
O2-S3.01 Feasibility and acceptability of self-sampling for rectal sexually transmitted infections (STI) among bisexual men in the USA
Authors: Dodge B , Van Der Pol B , Reece M , Malebranche D , Fortenberry D 
Published: July 2011

IntroductionRectal sexually transmitted infections (STI) are a common health concern for men who have sex with men (MSM). Studies have not yet determined the relevance of these pathogens among men who have sex with both men and women (MSMW). Screening for rectal STI is not currently a widespread option for bisexual men in the USA.MethodsQualitative data and self-obtained rectal specimens were collected from a diverse sample of bisexual men. Upon completion of the rectal self-sampling, each participant provided information regarding their overall experience with the process.ResultsFrom a total sample of 75 bisexual men, 58 participants provided self-obtained rectal samples. While most men did not test positive, a prevalence (10.3%) of C. trachomoatis infection was found in this sample. Men who collected samples reported overall acceptability and comfort with self-sampling for rectal STI. Privacy was a primary concern for men regarding self-sampling. Of the men who did not provide a rectal self-sample, the most common reason was having been tested in the recent past. Discussion: Self-sampling is a feasible and acceptable option when offered to bisexual men. Research and interventions are needed to ascertain which combinations of STI testing (including self-sampling) and treatment methods are most appropriate for diverse groups of bisexual men.
LBP-1.12 HIV and Hepatitis C prevalence in individuals leaving prison and entering drug and alcohol services in the area of highest HIV prevalence in the UK
Authors: Williams H , Axten D , Makia F , Teague A , Fox J 
Published: July 2011

BackgroundIntravenous drug users, particularly those in prison, are at high risk of acquiring HIV and Hepatitis C (HCV) and commonly do not access mainstream medical care. Missed opportunities for HIV and Hepatitis C testing in Intravenous drug users attending prisons are therefore common. By using oral swabs difficulties of venous access can be avoided. Lambeth has the highest prevalence of HIV in the UK and it is estimated that 15–20% of inmates at HMP Brixton are HIV positive.MethodsStaff delivered 26 walk-in clinics at a drug rehabilitation unit in Brixton over 5 months. The testing service was developed in close liaison with the drug and alcohol team and publicised using posters and education of reception staff. Oral swab testing for HIV and HCV was offered. A simple questionnaire was completed by attendees covering testing history and risk practice.Results35 individuals tested for HIV and HCV and were 80% male, 74.3% UK born, 48.6% white and 77.1% heterosexual. 37.1% were IVDU, median age was 36 (range 22–74). 57.1% individuals had previously tested for HIV, median time since last test was 4 years (range <1–15 years). 54.3% individuals had previously tested for HCV, median time since last test was 3 years (range <1–11 years). Median length of time in prison was 3 months (range <1–48 months). 48.6% and 51.4% had never been offered an HIV or HCV test in prison respectively. Only two individuals had tested for HIV and HCV in Prison. 14.3% individuals were already known to be HCV positive. 5.7% (N=2) individuals were newly diagnosed HCV positive but none tested HIV positive. 82.9% felt HIV/HCV testing should be offered in Prison. 71.1% felt this should be done using a mouth swab. 35% had no concerns regarding HIV/HCV testing but in those who did, dislike of needles, receiving a positive result and concerns regarding confidentiality were the commonest barriers to testing.ConclusionsPrevalence of previously undiagnosed HCV was high in this group but HIV prevalence was zero. Uptake of HIV/HCV testing was very low despite good publicity and support from the drug services. This suggests that this method is not a cost effective approach to HIV testing despite oral swabs representing an acceptable mode of testing. Half of attendees had not been offered an HIV or HCV test in prison which needs to be increased. Testing in drug rehabilitation services does not result in high uptake of testing or detection of undiagnosed HIV.
LBO-1.2 The potential impact of pre-exposure prophylaxis for HIV prevention among Men who Have Sex with Men (MSM) in Lima, Peru
Authors: Borquez A , Gomez G B , Caceres C F , Segura E R , Grant R M , Garnett G P , Hallett T B 
Published: July 2011

BackgroundHIV Pre-exposure prophylaxis (PrEP), the use of antiretroviral drugs by those HIV uninfected individuals to prevent HIV infection, recently demonstrated effectiveness in preventing acquisition in a high risk population of men who have sex with men (MSM). There is a need to understand if and how PrEP can be used cost-effectively. This study examines the programmatic implications of the iPrEX study: the only randomised controlled trial of PrEP among men who have sex with men (MSM) published last December in the New England Journal of Medicine.MethodsWe developed a mathematical model representing the HIV epidemic among Men who Have Sex with Men (MSM) and transgender people in Lima, Peru as a test-case. It considers differential infectiousness by stage, including the impact of antiretroviral treatment and different sexual practices, such as partnerships type and sexual positioning. The model was used to investigate the population-level impact, cost, and cost-effectiveness of PrEP under a range of implementation scenarios, and to develop possible strategies by which PrEP could be implemented.ResultsThe epidemiological impact of PrEP is largely driven by programme characteristics—coverage, prioritisation strategy and time to scale up—as well as individual's adherence behaviour. If PrEP is prioritised to key groups, it could be a cost-effective way to avert infection and save lives (up to 8% less new infections with 5% coverage). Across all our scenarios the estimated highest cost per DALY gained (US$$2755) is below the WHO recommended threshold for cost-effective interventions for the region (<US$$4608/DALY gained) see Abstract LBO-1.2 Figure 1. The impact of PrEP is reduced if those on PrEP decrease condom use, especially if the program has low coverage; but only extreme behaviour changes and a low PrEP efficacy would adversely impact the epidemic overall. However, PrEP will not arrest HIV transmission in isolation, due to its incomplete effectiveness, dependence on adherence, and the high total cost of programmes limiting attainable coverage levels.Abstract LBO-1.2 Figure 1ConclusionsThis study quantifies the epidemic and financial implications of different programmatic scenarios. While the implementation of a strategic PrEP intervention has potentially important financial implications (a substantial expenditure would likely be required to generate significant reductions in incidence), PrEP among vulnerable populations could be a cost-effective option comparable to currently available interventions for Men who Have Sex with Men (MSM) populations.
LBP-1.15 An evaluation of the long-term effectiveness, immunogenicity, and safety of Gardasil in previously vaccinated women
Authors: Saah A 
Published: July 2011

BackgroundThe GARDASIL long-term follow-up (LTFU) study is an ongoing extension of a pivotal randomised, placebo-controlled, double-blind, 4-year study to investigate the safety, immunogenicity, and effectiveness of quadrivalent Human Papillomavirus vaccine (qHPV) on the incidence of HPV 16/18-related cervical intraepithelial neoplasia (CIN) 2 or worse in 16–23-year-old women (Protocol 015).MethodsFollow-up of subjects will be accomplished in two ways: (1) registry-based follow-up for effectiveness data as well as safety data including but not limited to deaths, cancer, and hospitalisations; (2) active follow-up for blood collection for immunogenicity assessments at years 5 and 10 of the LTFU study. Effectiveness and safety analyses will occur approximately 2 years following completion of Protocol 015 and approximately every 2 years thereafter for 10 years. The current report represents the first of these efficacy and safety analyses. Cohort 1 included approximately 2700 subjects who received qHPV vaccine at the start of Protocol 015. Cohort 2 consists of approximately 2100 subjects who received placebo at the start of Protocol 015 and qHPV vaccine prior to entry into the LTFU. Vaccine effectiveness against HPV 16/18-related CIN 2 or worse was estimated by calculating the expected incidence of CIN 2/3 or worse in an unvaccinated (placebo) cohort using historical registry data. The primary analysis approach was per-protocol.ResultsThere were 1080 subjects that contributed to the follow-up period out of a total of 2195 eligible subjects in the per-protocol population in Cohort 1. In these subjects there were no cases of HPV 16/18-related CIN 2 or worse observed. There were also no cases of HPV 6/11/16/18-related CIN, vulvar cancer, and vaginal cancer observed. However, the follow-up time in person-years is insufficient to make a definitive statement about the effectiveness of the qHPV vaccine for the current time period.ConclusionsThe qHPV vaccine shows a trend of continued protection in women who were vaccinated up to 7 years previously, although there is as yet insufficient data to confirm that protection is maintained. The qHPV vaccine continues to be generally safe and well tolerated up to 6 years following vaccination.