bluuebunny/crossref_metadata_2025_split huggingface dataset:
O13.2 Can the UNAIDS Modes of Transmission Model Be Improved? A Comparison of the Original and Revised Model Projections Using Data from Nigeria
Authors: Prudden H J , Watts C H , Vickerman P , Bobrova N , Heise L , Ogungbemi M K , Momah A , Blanchard J F , Foss A M 
Published: July 2013

Mathematical modelling has increased our understanding of the HIV epidemic and played a key role in decision making. The UNAIDS Modes of Transmission (MoT) model has been used by 29 countries to analyse their HIV epidemics, with the results helping to guide and focus interventions. However, the simplistic compartmentalisation of the population within the model has raised concerns over its reliability.We compared the MoT model projections for Cross River, Nigeria, with a revised MoT model that incorporates additional heterogeneity (including subgroups for sero-discordant partnerships and individuals engaging in transactional sex) and updated parameters. We categorised population subgroups into ‘high-risk’, representing core groups, their bridging partners and sero-discordant partnerships; ‘medium-risk’, who are regular partners of ‘high-risk’ individuals; and ‘general population’, who are not linked to ‘high-risk’ or ‘medium-risk’ groups. Sensitivity analyses were undertaken and model projections assessed which population categories generated the highest incidence of HIV.The original MoT model projections suggest 73% of HIV infections occur in general population subgroups and 21% amongst ‘high-risk’ groups. Following revisions to the MoT, model projections estimate 76–94% (95%CrI) of new HIV infections are expected to occur in high-risk groups, who make up just 23% of the population, compared to 6–24% amongst general population subgroups. Changes in the distribution of infections result from the introduction of sero-discordant partnerships and ‘transactional sex’ groups (a relatively large subset of the population, often ignored in modelling analysis) in the model, which are classified as ‘high-risk’.The UNAIDS MoT remains an accessible and potentially useful model that can help inform intervention priorities. However, our findings strongly suggest that the current model may produce misleading findings, especially in more concentrated HIV epidemic settings. Results from this study indicate the need for UNAIDS to conduct a formal review of the MoT, and for further revisions to be made.
O13.3 Estimating the Epidemiological Impact of Antiretroviral Treatment on Heterosexual HIV Epidemics in South India: A Modeling Study
Authors: Mishra S , Mountain E , Pickles M , Vickerman P , Shastri S , Washington R , Becker M , Alary M , Boily M 
Published: July 2013

BackgroundIn south India, where intensive condom-based targeted interventions (TIs) for female sex workers (FSWs) have been successful, the potential impact of past, current, and proposed universal antiretroviral treatment (ART) eligibility criteria on concentrated HIV epidemics, remains unknown.MethodsWe developed a mathematical model of heterosexual HIV transmission to simulate the HIV epidemic in three south Indian districts, using district-specific epidemiological data. The model was calibrated to HIV prevalence by risk groups (low-risk, clients, FSWs), population size, and ART coverage. Assuming that condom-based TIs, HIV testing and treatment access, and retention in HIV-care are sustained at current levels, we compared the following scenarios against no ART: (a) continue with the previous eligibility criteria (CD4 ≤ 250 cells/μL) from the start of each district’s ART programme; (b) expand from previous to current eligibility (CD4 ≤ 350 cells/μL) after November 2011; and (c) expand to early ART at any CD4 cell count after January 2013.ResultsWithout ART, the three districts achieve local elimination between the years 2040 and 2082, and by 2035–2063 under the current ART programme (eligibility criteria: CD4 ≤ 250 cells/μL prior to November 2011, CD4 ≤ 350 cells/μL thereafter). By January 2013, the current ART programme has potentially averted 7.8–11.0% of HIV infections, and saved 32–44 life-years per 100-person years on ART, in addition to gains achieved by local TIs. By 2023, the additional fraction of HIV infections averted by ART(compared to sustained TIs without ART) under scenarios A, B, and C are 21–42%, 33–57%, and 43–69%, respectively, and the incremental gains in life-years per 100-person years on ART are 120–140, 68–111, and 40–91, respectively.ConclusionsIn declining HIV epidemics with sustained TIs, current ART programmes and proposed ART expansion could provide additional epidemiological impact. The medium-term incremental gains become smaller as eligibility expands but access and retention in care remain constant.
O13.4 An Ethnographic Mapping Study of “Money Boys” and the Male Sex Trade Industry in Chengdu, South West China
Authors: Yu B , Wang X , Zhang J , Ma X , Khan S , Blanchard J , Lorway R 
Published: July 2013

BackgroundHIV prevalence studies have found that male sex workers (MSWs) in China have high HIV prevalence, ranging from 5% to 9%. These “money boys” have been identified as a particularly vulnerable population, and it is imperative to develop effective programmes for HIV prevention in this population.ObjectivesThe study had 4 objectives: (1) to describe the operation of the male sex work industry; (2) to identify the environmental and structural factors that shape the risk practises of MSWs (3) to map solicitation venues and estimate the size of the MSW population to guide programme design and focus.MethodEthnographic and geo-mapping techniques were combined to locate, enumerate and contextualise different aspects of the male sex trade industry. MSWs, network operators and brothel owners provided size estimates of MSWs for specific hotspots. Participant observation and key informant interviews were employed to understand the risk practises described by participants.ResultsAccording to the ethnographic findings, MSWs are often recruited from rural villages via labour markets and from the urban gay community; they had high client volumes and were mobile within the city and between cities throughout China. Thirty MSW venues were mapped and 23 venues were validated. Systematic review and validation of gay websites revealed 48 brothels. Local prevention programmes reached only 16 venues. Five public toilets, 4 bathhouses and 7 parks, where MSWs frequented, were also mapped. The majority of venues were located within the commercial core, with easy access to public transportation. The MSW population was estimated between 373 and 1200. Some MSWs (n = 97) advertised on gay websites and through cell phone applications.ConclusionDespite criminalization, there is a thriving male sex trade in Chengdu. Local efforts to reach these communities need to be scaled up to address programme coverage gaps.
O13.5 The HIV Modes of Transmission Model: A Systematic Review of Its Findings and Adherence to Guidelines
Authors: Shubber Z , Mishra S , Vesga J F , Boily M C 
Published: July 2013

BackgroundThe HIV Modes of Transmission model (MOT) estimates the annual percentage distribution of new HIV infections (PNI) by key risk groups. It was designed to guide country-specific HIV prevention policies. To determine if the MOT produced context-specific recommendations, we analysed the MOT results by regions and epidemic types and explored the factors (e.g. data inputs, adherence to guidelines) influencing the differences.MethodsWe systematically searched MEDLINE, EMBASE, UNAIDS reports, and contacted UNAIDS country directors for published MOT results from 2003 (1st published MOT).ResultsWe included 4 journal articles and 20 UNAIDS reports covering 29 countries. The largest PNI was among the low-risk group (one heterosexual partner) in 13 countries [range 26–63%], and increased with low-risk population size. The estimated PNI among female sex workers (FSWs) was universally low [median 1.3%, range 0.04–14.4%], and showed little variability by region and epidemic type despite variation in sexual behaviour e.g. number of partners. In India and Thailand, where FSWs play an important role in transmission, the PNI among FSWs was 2% and 4% respectively. In contrast, the PNI among men who have sex with men (MSM) varied across regions [MSM, range 0.1–89%] and increased with MSM population sizes. The PNI among people who inject drugs [PWID, range 0–82%] was largest in ‘early-phase’ epidemics with low overall HIV prevalence. Most MOT studies are being conducted and reported as per guidelines. However, many countries (n = 23) reported data limitations - especially on high-risk groups - when parameterising the MOT.ConclusionAlthough countries are generally performing the MOT as per guidelines, results showed little variation in MOT outputs (except MSM and PWID) by regions and epidemic types. Homogeneity in MOT outputs for FSWs, clients and low-risk population may limit the utility of MOT for guiding country-specific interventions in heterosexual HIV epidemics.
O13.6 Focusing the Delivery of the English National Chlamydia Screening Programme: Exploring Opportunities to Expand Testing Within Local Services
Authors: Simms I , Woodhall S C , Nardone A , Mercer C H , Talebi A , Hughes G 
Published: July 2013

BackgroundThe National Chlamydia Screening Programme (NCSP) seeks to increase rates of chlamydia diagnosis amongst young people aged 15–24 across the 326 English Local Authorities (LA). 68% of screens and 79% of diagnoses are made in the community sexual health, general practise, pharmacy, termination of pregnancy (TOP) and genitourinary medicine (GUM) services that take part in the NCSP. These ‘Core Services’ are central to the delivery of the programme but not all clinics screen for chlamydia. This study was undertaken as part of a project to inform optimum services configuration to increase diagnostic rates to improve chlamydia detection and infection control.MethodsDiagnoses of genital chlamydia recorded in data from sexually transmitted disease clinics and NCSP surveillance datasets for 2011 were aggregated to LA level. Overall diagnostic rates (outcome) were calculated using Office of National Statistics (ONS) population estimates for the 15–24 year age group. This information was analysed together with the total testing at each Core Service and ONS area classification. Data were analysed using multivariable negative binomial poisson regression and spatial mapping techniques.ResultsOverall chlamydia diagnostic rates were associated with increased rates of testing in community health services (RR = 1.02; p < 0.0001), general practise (RR = 1.01; p = 0.0176) and GUM (RR = 1.03; p < 0.0001) but not pharmacy or TOP. Diagnostic rates varied by geographic location (p < 0.0001), lower rates being seen in ‘Central London’ (RR = 0.63; 95% CI = 0.50–0.80), ‘London Suburbs’ (RR = 0.77; 95% CI = 0.61–0.96) ‘Southern England’ (RR = 0.63; 95% CI = 0.51–0.78) and ‘Outer London’ (RR = 0.64; 95% CI = 0.50–081). Diagnostic rates also increased as the range of service types contributing to testing increased (p = 0.0427).ConclusionsThe analysis highlights the importance of community based testing and the provision of a range of services to achieving high rates of chlamydia detection. The study is being extended to investigate patient flow and service attendances within and between LAs in relation to gender, age group, ethnicity and service type.
O14.1 Bacterial Vaginosis-Associated Bacteria (BVAB) and Non-Gonococcal Urethritis (NGU)
Authors: Manhart L E , Khosropour C M , Liu C , Gillespie C W , Depner K , Fiedler T , Marrazzo J M , Fredricks D N 
Published: July 2013

BackgroundTraditional cultivation approaches have not identified additional pathogens responsible for the 45% of non-gonococcal urethritis (NGU) cases with no identified aetiology. Cultivation-independent methods have identified novel bacteria associated with female reproductive tract disease, particularly bacterial vaginosis (BV). We evaluated the association of NGU and 5 newly described BV-associated bacteria (BVAB).MethodsEnglish-speaking, heterosexual men aged 16 years attending the STD clinic in Seattle, WA between May 2007 and July 2011 were eligible if PCR tests forChlamydia trachomatis,Neisseria gonorrhoeae,Trichomonas vaginalis, Mycoplasma genitalium, andUreaplasma urealyticum-biovar2 were negative. Cases were men with visible urethral discharge or 5 PMNs/HPF in urethral exudates. Controls were men with no visible urethral discharge and < 5 PMNs/HPF. Urine was tested forAtopobium, BVAB-2, BVAB-3,Megasphaera spp., andLeptotrichia/Sneathia spp.using quantitative taxon-directed PCR.ResultsCases (n = 157) and controls (n = 191) were similar with respect to age, education, and income. Mean age was 34.7 (SD ±9.9) and most were white.Leptotrichia/Sneathiawas significantly associated with NGU (25/157 (15.3%) vs. 6/102 (5.9%), p = 0.03) and BVAB-2 was detected more often in cases than controls (7/157 (4.5%) vs. 1/102 (1.0%), p = 0.15). BVAB-3 (n = 2) andMegasphaera(n = 1) were uncommon, but only detected in men with NGU. In contrast,Atopobiumwas not associated with NGU (8.3% vs. 7.8%, p = 1.0). Quantity of bacteria did not differ between cases and controls for any of the 5 candidate pathogens. Among treated cases, doxycycline was somewhat more effective than azithromycin for clinical cure of men withLeptotrichia/Sneathia(9/10 (90%) vs. 7/12 (58%), p = 0.16), and BVAB-2 (3/3 (100%) vs. 0/3 (0%), p = 0.10).ConclusionLeptotrichia/Sneathiawas significantly associated with NGU. BVAB-2, BVAB-3, andMegasphaerawere less commonly detected, but most often identified in men with NGU and rarely or never in men without NGU. Doxycycline may be more effective against these newly identified bacteria than azithromycin.
O14.4 Microbiologic Aetiology of Proctitis Diagnosed in an Urban STD Clinic
Authors: Cohen S E , Bernstein K T , Stephens S C , Philip S S 
Published: July 2013

BackgroundSexually transmitted proctitis occurs among persons who participate in receptive anal intercourse and is a risk factor for HIV acquisition.N. gonorrhoeae,C. trachomatis(including LGV),T. pallidum, and Herpes Simplex Virus (HSV) are the most common pathogens identified. The distribution of microbiologic aetiology of proctitis has implications for empiric treatment guidelines. Methods: We describe the microbiologic aetiology of clinical proctitis among men who have sex with men seen at the municipal STD clinic in San Francisco.N. gonorrhoeaeandC. trachomatiswere tested using a nucleic acid amplification assay, HSV was tested using polymerase chain reaction, andT. pallidumwas tested using a non-treponemal antibody test, withT. pallidumparticle agglutination confirmation. Results: Between January 1, 2004 and December 31, 2012, there were 1271 men diagnosed with clinical proctitis at the clinic. The number of cases of proctitis diagnosed annually did not increase over this interval, despite increasing rates of rectal gonorrhoea and Chlamydia. Overall, 820 (65%) of the cases had no microbiologic aetiology identified and nearly half were among HIV-infected men. Two-hundred sixty-three (21%) had gonorrhoea, 205 (16%) had Chlamydia, 53 (4.2%) had both gonorrhoea and Chlamydia, 28 (2.2%) had syphilis and 105 (8.3%) had herpes. Cases in which no microbiologic aetiology was identified were not more likely to have a repeat clinic visit within 14 days of diagnosis compared with those with Gonorrhea or Chlamydia (6.3% vs. 6.8%).ConclusionSTD clinics can be sentinel sites to assess proctitis trends. No microbiologic diagnosis was identified in almost half of proctitis cases evaluated during the study interval and these cases were not more likely to experience treatment failure, suggesting that current empiric treatment guidelines are effective. Future studies should use advanced molecular techniques to evaluate the role of novel and emerging pathogens in the aetiology of proctitis.
O14.5 Occurrence of Vaccine and Non-Vaccine Human Papillomavirus (HPV) Types in the Female Population Before and After the HPV Vaccination
Authors: Paavonen J 
Published: July 2013

Understanding type replacement following HPV vaccination is important.We studied the occurrence of specific HPV types in a large cohort of young women from Finland who participated in a population-based HPV vaccination trial. A total of 4,808 16- to 17-year-old women were enrolled in the randomised PATRICIA efficacy trial of HPV16/18 vaccine (Cervarix) compared to hepatitis A virus (HAV) vaccine. HPV infection was assessed from cervical samples obtained every 6 months for 4 years post-vaccination and tested for 14 high- risk HPV types and 2 low-risk HPV types. HPV16/18 vaccination coverage varied from 1% to 22% by participating community. HPV incidence rate ratios (IRRs) in baseline positive women vs. baseline negative women were calculated. In the control arm, baseline HPV18-positive women showed an increased risk of acquiring other clade A7 HPV types (39/45/59/68) (IRR 1.8, 95% confidence interval = 1.01–3.1). No excess risk of non-vaccine HPV types was observed in the baseline HPV DNA-negative HPV16/18-vaccinated women compared to the baseline HPV DNA-negative control women. Similarly, no excess risk was observed in the baseline HPV-16/18-positive HPV16/18-vaccinated women compared to the baseline HPV16/18-negative women. In conclusion, we found no increased rates of non-vaccine HPV types suggestive of type-replacement up to 4 years post-vaccination among HPV16/18-vaccinated young women. However, surveillance of clinical trial cohorts and other populations in countries with HPV vaccination programmes implemented with focus on vaccination coverage rates are warranted.
O14.6 Aetiology of Infectious Proctitis Differs by HIV Status
Authors: Bissessor M , Fairley C K , Read T R , Denham I M , Bradshaw C S , Chen M Y 
Published: July 2013

BackgroundSexually acquired rectal infections are common among men who have sex with men (MSM) and increase the risk of HIV acquisition. We aimed to compare the spectrum of pathogens responsible for infectious proctitis between HIV positive and HIV negative MSM.MethodsWe undertook a study of MSM who presented to Melbourne Sexual Health Centre with symptomatic proctitis between March 2003 and December 2011. Men with proctitis were tested for gonorrhoea by culture, chlamydia by strand displacement assay, and herpes simplex virus (HSV) by PCR. Chlamydia positive specimens were genotyped for lymphogranuloma venereum (LGV).ResultsAmong the 279 men in the study, 141 were HIV positive and 138 were HIV negative. The median CD4 count among HIV positive men was 423 (range 189–1026). The prevalence of infections among HIV positive and HIV negative men respectively was: chlamydia (23.4% versus 21.7%, p = 0.7); gonorrhoea (13.4% versus 10.8%, p = 0.5); HSV-1 (14.2% versus 6.5%, p = 0.04); HSV-2 (22% versus 12.3%, p = 0.03); and LGV (7.8% versus 0.7%, p = 0.004). HIV positive men were more likely to have multiple infections (17.7% versus 8.6%, p = 0.017). Only 32% of men with HSV associated proctitis had visible anal ulceration.ConclusionAmong MSM presenting with proctitis, HSV, LGV and multiple infections are more common among HIV positive men than among HIV negative men. MSM presenting with proctitis require comprehensive testing and treatment for possible pathogens including herpes in the absence of anal ulceration.
O15.1 Sub-Optimal CD4 T-Cell Recovery in HIV-1 Subtype C Patients on Antiretroviral Therapy: A Search For Predictive Biomarkers and Baseline Characteristics
Authors: Retshabile G , Kisanga E R , Gaseitsiwe S , Moyo S M , Bussmann H , Makhema J , Essex M , Marlink R , Musonda R 
Published: July 2013

BackgroundDespite receipt of combination antiretroviral therapy (cART) and subsequent viral suppression some 15–30% of treated HIV infected patients fail to achieve optimal CD4 T-cell reconstitution. Sub-optimal CD4 recovery has been associated with unfavourable outcomes for patients on cART. We assessed markers of immune activation, microbial translocation and patient baseline characteristics for associations with sub-optimal CD4 T-cell recovery post cART initiation.MethodsThis was a retrospective case control analysis of CD4 T-cell recovery from a completed (2002–2007) clinical trial, the Adult Antiretroviral Treatment and Drug Resistance (“Tshepo”) Trial, in Gaborone, Botswana. Cases (sub-optimal CD4 response) were defined as CD4 ≤ 200 cells/µl at 12 months post ART initiation, with virologic suppression achieved within 6 months. Microbial translocation (sCD14) and immune activation (interferon-gamma) markers were quantified using Enzyme Linked Immuno-Sorbent Assays on a subset of 30 cases and 30 controls gender matched baseline and 12 month plasma samples. Univariate and logistic regression analysis were used to assess predictors of sub-optimal CD4 T-cell recovery.ResultsFifty-one cases (21%) from 249 virologically suppressed patients had sub-optimal CD4 recovery. The median age was 33.39 years and 69.9% were female. Baseline CD4 count < 100cells, haemoglobin and aspartate transaminase were associated with sub-optimal CD4 recovery (adjusted OR (aOR) = 3.03 95% CI [1.65, 5.57], p < 0.001; aOR = 0.81 [0.67, 0.99], p = 0.038 and aOR = 1.03 [1.00, 1.05], respectively). sCD14 levels were significantly different between cases and controls, p = 0.0011, at 12 months. Baseline Tuberculosis infection, body-mass-index, interferon-gamma, alanine transaminase and age were not associated with poor CD4 T-cell response.ConclusionLow baseline CD4 T-cell count, haemoglobin, aspartate transaminase and sCD14 levels are predictive of suboptimal CD4 T-cell recovery in this cohort of HIV-1 subtype C infected patients. These markers are potentially useful in identifying patients who need frequent clinical monitoring to minimise unfavourable outcomes associated with poor CD4 T-cell recovery.
O15.2 Comparison of the Roche Cobas 4800 CTNG Test with Microbial Culture For DetectingNeisseria Gonorrhoeaein Genital and Non-Genital Specimens in New Zealand
Authors: Miller A , Bromhead C , Jones M , Whiley D , Upton A 
Published: July 2013

BackgroundIn New Zealand it has been usual practise to detectNeisseria gonorrhoeae(NG) by culturing endocervical and urethral specimens obtained by pelvic examination. However there is a significant false negative rate. The use of newer nucleic acid amplification tests (NAATS) increases the detection of NG and allows testing of non-invasively collected samples. A large retrospective audit was performed on 18,913 microbial culture and cobas 4800 NG PCR results with the aim to determine if urogenital and non-genital specimens could be screened without the need for supplementary testing of positive results.MethodsResults from culture and PCR were compared; discrepancies were resolved by clinical correlation and/or an in-house assay targeting theopagene and theporApsuedogene.ResultsNG PCR diagnosed 33% more urogenital and 25% more rectal infections than culture; and testing of non-invasive specimens by PCR resulted in 37% more patients being screened for infection. Female urine is not suitable as a sole screening specimen by this assay as sensitivity was only 86.7%. There were insufficient pharyngeal or eye swabs available for the study to rule out the need for supplementary testing by additional DNA targets.This study also showed an association between ‘failed’ cobas 4800 results and NG positive culture results, likely caused by mucopurulent discharge. Treating specimens with 1.4% Dithiothreitol enabled resolution of 89% of these specimens, of which 18% were positive for CT and/or NG.In our population, 8% of NG positives wereporAnegative, and 22% wereopanegative. Confirmatory testing of a pharyngeal specimen identified a cross-reacting commensal Neisseria which gave a false positive cobas 4800 NG result.ConclusionThe cobas 4800 NG test is acceptable for urogenital and rectal specimens without supplementary testing in our low prevalence (< 1%) population, however other non-genital sites require confirmation.