bluuebunny/crossref_metadata_2025_split huggingface dataset:
P1-S5.33 Timing of incident STI relative to sex partner change in young women
Authors: Ott M , Harezlak J , Ofner S , Fortenberry J D 
Published: July 2011

ObjectivesPartner concurrency is associated with STI acquisition, even when partners are sequential (ie, serial monogamy). However, little is known about the timing of STI relative to partner change. This is due, in part, to lack of documentation of STI before and after partner change. Using prospective behavioural and STI screening data, we compared the proportion of an STI occurring before and after partner change within a 12-week period.MethodsAs part of a larger study of risk and protective factors for STI in a mid-sized US city, young women provided weekly vaginal swabs and completed daily diaries of sexual behaviours for a 12-week period twice a year for up to 8 years. Vaginal swabs were tested for chlamydia (CT), gonorrhoea (NG) and trichomonas (TV) using amplified DNA-based tests. We limited analysis to the 12-week periods in which young women reported one sex partner change (ie, 2 sequential partners, no overlap). STIs with partner 1 were defined as those diagnosed before 1st sex with partner 2; STIs with partner 2 occurred after 1st sex with partner 2. Published data shows a higher odds of infection after a partner change (compared to no change) with the ORs ranging from 2.0 to over 4.0. We used a non-equivalency test to identify the odds for not detecting differences in STI acquired with partner 1 vs partner 2. If there is a difference between rates for partner 1 and partner 2, it will not be higher than the upper bound of the CI.ResultsNinety-two women provided 111 12-week periods with one partner change. Mean age was 17.8 years; 94% were African American. Rates of STI were high for both Partner 1 and Partner 2 (see Abstract P1-S5.33 table 1). For CT, TV, and any STI, the upper bound of the 95% CI was lower previously reported rates. We have 95% confidence that the OR for infection with partner 2 vs partner one is not greater than 1.83 for CT, 1.47 for TV, and 1.68 for any STI. In contrast, the true OR for GC may fall within or higher than previously reported. We have 95% confidence that the OR for GC infection with partner 2 vs partner 1 is between 0 and 9.7.Abstract P1-S5.33 Table 1Partner 1 n (%)Partner 2 n (%)95% CI for OR*CT11 (9.9%)10 (9.0%)0 to 1.83GC3 (2.7%)9 (8.1%)0 to 9.70TV8 (7.2%)5 (4.5%)0 to 1.47Any STI21 (18.9%)19 (17.1%)0 to 1.68*One-sided OR.ConclusionMany young women already have an STI when a partner change occurs. These data suggest that the relationship contexts of partner change–in addition to the risk characteristics of a new partner–are also relevant to the epidemiology of STI in a specific common form of partner concurrency (ie, serial monogamy).
P1-S5.34 Diffuse distribution and extensive disassortative mixing ofChlamydia trachomatisgenotypes between ethnic groups in Paramaribo, Suriname
Authors: Bom R , van der Helm J , Sabajo L , de Vries H , Grunberg A , Bruisten S 
Published: July 2011

BackgroundSuriname is a multicultural society with many ethnic groups, such as Creoles and Maroons (descendants from the African diaspora due to slave trade), Indian, Javanese and Chinese (descendants from labour immigrants), Caucasian (descendants from Dutch immigrants during colonisation) and indigenous Amerindian people. The prevalence of Chlamydia trachomatis (CT) in Suriname is high (between 10 and 23% among respectively low-risk birth control and high-risk STI clinic visitors). We aim to study the influence of sexual mixing on the transmission of CT in Paramaribo, Suriname.MethodsSamples were collected at a birth control clinic and an STI clinic in Paramaribo. Detailed questionnaires were given to visitors, concerning ethnic background, both self considered as well as that of their parents. The samples were tested with NAAT for CT. Positive samples were typed using multilocus sequence typing (MLST). Minimum spanning trees were generated and clusters were combined with the epidemiological data.ResultsWe retrieved full MLST profiles for 181 of 233 samples. Eighteen ompA variants from nine different genovars were found, which were split up into 68 MLST sequence types. Although the predominant genovars were E (32.6%), F (18.8%) and D (18.8%), a remarkably large proportion was genovar I (14.4%). The sequence types of most genovars clustered together, but possible recombination events were seen for genovar B, D, E and J. The minimum spanning tree showed two large clusters for genovar E and F (30 and 19 samples each) and 28 smaller clusters (2 to 7 samples). More than half of the sequence types (38/68) consisted of singletons. When ethnicity was superimposed on the minimum spanning tree, it was diffusely distributed over all clusters (Abstract P1-S5.34 figure 1). Almost all participants (175/181) had sex partners in Suriname. Disassortative sexual mixing with other ethnical groups (having a partner from a different ethnic background) was reported by 56.0% (98/175) of the participants.Abstract P1-S5.34 Figure 1Ethnical background superimposed on the minimum spanning tree generated from the MLST data of 181 chlamydial infections from Paramaribo, Suriname. Depicted are the predominant ethnic groups for Chlamydia infections: Creoles are given in black, people from mixed race in grey, Maroons in dark grey and Javanese people are given in light grey. Indian, Amerindian and Caucasian people are given in white.ConclusionsThe diversity among chlamydial types within the Surinamese population was shown to be high, as about half of the sequence types were unique. The distribution of sequence types over the population seemed not to be influenced by ethnical background. This could possibly be explained by the high degree of disassortative mixing. This is in contrast to previous studies on HIV transmission in Suriname where clustering within ethnic groups was found and disassortative mixing was lacking.
P1-S5.35 Multiple concurrent sexual partnerships among adolescents in Tanzania and South Africa: a comparison between areas with contrasting level of HIV magnitude
Authors: Mmbaga E , Helleve A , Leyna G , Masatu M , Onya H , Klepp K I 
Published: July 2011

BackgroundModelling and empirical evidence suggest that population differences in the practice of concurrent sexual partnership could be the most important explanation of the observed heterogeneity in HIV epidemic in sub-Saharan Africa. Biomedical and some behavioural evidence have not sufficiently explained the variation. This study aimed at comparing the rate of concurrent sexual partnerships among adolescents in Arusha, Tanzania and Polokwane, South Africa, two areas with contrasting level of HIV magnitude.MethodsA baseline cross-sectional study involving junior secondary school adolescents in Arusha, Tanzania and Polokwane South Africa was conducted in 2010 as part of the school-based Health Intervention project (LASH). Adolescents from 12 randomly selected schools from each country were interviewed regarding their socio-demographic characteristics, sexual behaviours and substance use. Data were entered and analysed using SPSS statistical package.ResultsA total of 2408 adolescents from Arusha and 1649 from Polokwane participated in the study. Adolescent interviewed in Arusha were significantly older than their Polokwane counterpart (Mean age (SD) 19.3(0.5) and 15.5(0.7), respectively, p<0.001). The overall prevalence's of reported multiple concurrent sexual partnerships were 9.2% in Arusha and 25.2% in Polokwane (OR, 3.7, 95% CI 3.0 to 4.7. Both males and Females adolescents from Polokwane were significantly more likely to report concurrent sexual partnerships than those from Arusha (p<0.001). Moreover, adolescents from Polokwane reported practice of other HIV risk behaviours as compared to those in Arusha (p<0.001). History of sexual experience (vaginal, oral, anal), ever use of condom and substance use were independent predictors of multiple concurrent sexual partnerships in both sites.ConclusionsHigh practice of multiple concurrent sexual partnerships among adolescent living in high HIV prevalent area as compared to those in low prevalence area indicate that concurrent partnership could be the most important explanation of the observed heterogenic HIV transmission in sub-Saharan Africa. Being sexually active and substance use predict practice of concurrent sexual partnerships among adolescents. Delaying sexual debut and addressing substance use among adolescents may have a significant impact on HIV epidemic.
P1-S5.36 Concurrency among women <25 years of age screened in family planning and reproductive health clinics in US Public Health Service Region X, January 2009–June 2010
Authors: Nakatsukasa-Ono W , Fine D 
Published: July 2011

BackgroundTo better understand the dynamics of STIs and HIV, researchers are increasingly examining the determinants and consequences of sexual networks. In January 2009, the Infertility Prevention Project (IPP) in US Public Health Service Region X-one of 10 regional projects funded by the Centers for Disease Control and Prevention (CDC)-began collecting a new network sexual risk behaviour for IPP chlamydia (CT) tests. The Region X IPP decided to collect sex partner (SP) concurrency based on the literature, research conducted in California, CDC input and regional interest.MethodsCT positivity (CT+) was calculated by demographics, sexual risk behaviours, SP concurrency and clinical findings for 94,433 tests among women <25 years of age screened in Region X IPP family planning and reproductive health (FP/RH) clinics from January 2009 to June 2010. Univariate and multivariate analyses were conducted.ResultsOf the 94 433 tests, 62% were age 20–24, and 72% were non-Hispanic white. 14% of clients reported their SPs definitely, 41% reported “possibly” and 38% reported it was “unlikely” their SPs had concurrent SPs in the last 12 months. CT+ ranged from 7.6% among clients reporting their SPs “definitely” had concurrent SPs to 5.2% among those reporting it was “unlikely.” Clients reporting their SPs “definitely” or “possibly” had concurrent SPs were more likely to report other sexual risk behaviours and have clinical findings on examination. Significant (p<0.001) factors for CT+ included SP concurrency (definitely: AOR=1.20; possibly: AOR=1.25); age (15–19 years: AOR=1.34); race/ethnicity (Black: AOR=1.55; American Indian/Alaska Native: OR=1.60; Native Hawaiian/Other Pacific Islander: AOR=1.92); CT infection in the last 12 months (AOR=2.06); new SP (AOR=1.43), multiple SPs (AOR=1.48), symptomatic SP (AOR=4.07) in past 60 days; clinical findings (cervicitis or PID diagnoses; AOR=2.22).ConclusionsIt is feasible to collect SP concurrency with female clients in the context of a clinic visit. SP concurrency was a significant predictor of CT+ beyond other risk factors. Results for clients who reported their SPs “possibly” had concurrent SPs may reflect clients being less knowledgeable about their SPs' sexual behaviours. Findings confirm the importance of assessing network characteristics such as SP concurrency, the need to incorporate SP concurrency in risk reduction counselling, and the potential to use this measure in empirically based screening decisions.
P1-S5.39 Triple jeopardy? Sexual networks of syphilis & HIV infection among heterosexuals, MSM, and bisexual men in North Carolina
Authors: Doherty I , Pasquale D , Liebman A , Adimora A , Leone P 
Published: July 2011

BackgroundThe velocity of STI spread depends in part on the formation of sexual partnerships and the structure of sexual networks. Dual outbreaks of HIV and syphilis have persisted in NC since 2001 among young black men who have sex with men (MSM). During 2007–2009, the incidence rate of early stage syphilis increased 600% in County X from 9/100 000 to 57/100 000; the outbreak involved MSM, bisexual men (MSMW), heterosexual men (MSW), and women. We sought to determine if bisexual men bridged MSMs and heterosexuals to facilitate syphilis and HIV spread in both populations.MethodsWe abstracted public health department charts in County “X” for early stage syphilis cases and HIV for black men ages 15–30 during 2006–2009. We documented each sexual and social tie, permitting sociometric analysis.ResultsOf the 532 cases with syphilis, HIV, or both infections, 69% were male. The per cent of males declined with age from 24% to 18% to 13% for ages 21–25, 26–30, and 31–35 respectively, whereas women in each age group were equally distributed between 16% and 18%. Women, MSW, and MSM, accounted for 31%, 32% and 30% respectively of cases; 7% were bisexual men. Though most heterosexuals had only syphilis, 16% were HIV+ and 38% of them were coinfected. Among 196 bisexual and MSM, 73% were HIV+; of these, half were coinfected. On the basis of timing of HIV and syphilis diagnoses and syphilis stage, an estimated 33% of HIV+ men may have serosorted. Unlike other MSM populations, these cases did not use methamphetamine; 35% reported marijuana use. Crack cocaine use was reported for 16% of MSW and 33% of women. A total of 2099 individuals (cases, uninfected contacts, and anonymous partners) made up the network divided into 293 components. The largest component of 261 people (Abstract P1-S5.39 figure 1) was predominantly MSM including 10 of the 36 MSMW. None of MSMWs' female partners had other partners, suggesting that onward transmission did not occur. Heterosexuals, engaging in transactional sex, comprised the second largest component involving at least 135 individuals; all cases were syphilis-infected.Abstract P1-S5.39 Figure 1Infection Status.ConclusionsContemporaneous syphilis and HIV epidemics persist among MSM; neither serosorting nor methamphetamine use fuels spread. Heterosexuals experienced a syphilis outbreak driven in part by transactional sex and crack cocaine use. Bisexual men did not bridge the populations. Frequent dual screening among MSM is critical to impede further transmission of both STIs.
P1-S1.22 HSV-2 prevalence across a pastoral landscape: transmission and transition among the Himba and Tjimba populations
Authors: Hazel A , Foxman B , Low B 
Published: July 2011

BackgroundSexual partnerships take multiple forms among the Himba and Tjimba people living in Northwestern Namibia, including polygynous and monogamous marriage, and long- and short-term extra-marital partnerships. We hypothesised that HSV-2 prevalence would be higher in regions that are connected to local urban areas, because these should be sites of more frequent anonymous partner exchange.MethodsIn 2009, we surveyed 30 villages, obtaining HSV-2 status (using the BioKit Rapid Test for HSV-2) and demographics, home village, recent travel patterns and sex partnerships (n=446). We estimated prevalence (a) for the entire population (b) for all women and men and c) for individual villages. Logistic regression models were fit to test the correlation between risk of infection and travel patterns.ResultsOverall HSV-2 prevalence was 36.5%, with higher rates among women (50.5%) than men (23.3%). In contrast to expectation, the highest HSV-2 prevalences were found in some of the most remote regions. To explore this further, we built a network model that superimposes travel patterns onto sex partnership data. Using this model, we observed that older travel corridors (eg, travel from home village to extended-family associated villages) were more associated with higher HSV-2 transmission than newer corridors (eg, travel to local cities to hang out). Ethnographic interviews suggest that differences in the nature of relationships that occur in urban areas (eg, lower contact frequency, higher condom use) may explain the difference between observed and predicted.ConclusionsIn this population cultural and economic transitions that lead to more travel into urban areas were not associated with increase in HSV2 prevalence, probably because these relationships are deemed more risky. Shifting attitudes about sex and sex partnerships are likely to affect future STD transmission in this population.
P1-S5.42 Prevalence of transitional and embedded concurrency within a prospective cohort of urban adolescent females
Authors: Matson P , Chung S E , Fortenberry J D , Ellen J 
Published: July 2011

BackgroundStudies have found that concurrent sexual partnerships, as opposed to cumulative number of sex partners or serially monogamous partnerships play a pivotal role in rates of STI transmission. Different patterns of concurrency have different consequences to STI transmission as these patterns result in diverse network structures from within which to disseminate disease. Our objective was to determine the prevalence and types of concurrent partnerships within a prospective cohort of urban adolescent females.MethodsA cohort of adolescent females (N=63), aged 16–19 at baseline, were recruited from health clinics and community venues in Baltimore, MD and completed daily diaries about each current sex partner on a Palm Smartphone continuously for up to 18 months. As data collection is ongoing, relationships that were at least 8 weeks long were selected for this analysis. Partner names were confirmed by participants at regular intervals to ensure the same partner was followed over time. Sex partners were considered concurrent if they were named by the participant in the same week. Concurrent partners were categorised as either embedded or transitional relative to each relationship. A side partner was categorised as embedded if the week(s) that partner was named were completely contained within the weeks of the relationship. A side partner was categorised as transitional if weeks that the partner was named either preceded or persisted beyond the relationship or if the partner was only named in a single week within the first or last 4 weeks of the relationship.ResultsFifty-five participants had a relationship of at least 8 weeks duration, of these 55 relationships 28 (51%) had a concurrent partner within the relationship, with a mean (SD) of 2.7 (2.6) concurrent partners. Of the 28 relationships that contained concurrency, transitional concurrency was most prevalent (43%), followed by both transitional and embedded (39%), and embedded only (18%). Among relationships with concurrency, 25% had a gap of >4 weeks within the relationship, as a result partners initially classified as transitional subsequently became embedded. There was no difference in relationship duration for those with and without concurrency.ConclusionsTransitional concurrency may reflect adolescents' intentions of serial monogamy. Future data collection is needed to gain an improved understanding of adolescents' motivations for concurrent sexual partnerships.
P1-S6.01 Controlling the heterosexual HIV epidemic in low-prevalence domains
Authors: Lehman C , Keen A , Kerr B 
Published: July 2011

BackgroundHIV/AIDS has a manifest ability to swell to epidemic proportions and debilitate entire societies. Currently, the disease remains below the level of a generalised epidemic1 in the USA and many other developed nations. Yet the number of reported HIV infections continues to expand steadily.2 The same strains of virus affect all humans, but their ecology and epidemiology are markedly different in opposite-sex vs same-sex communities. Variance terms in the transmission equations of opposite-sex communities are reduced in same-sex communities, changing the dynamics of the disease and the interventions that could successfully control it.Methods and ResultsWe apply mathematical disease models of minimal complexity and higher complexity equation-free network models to show how (1) purely epidemiological forces are sufficient to explain the rapid spread of the virus through male same-sex communities, independent of usual assumptions of more dangerous or careless sexual practices in those communities3, (2) the expansion tendencies of HIV can be counteracted in national testing and treatment programs aimed at breaking the spread of infection, and (3) simple behavioural changes resulting from increased awareness of infection through increased testing4 can conceivably bring the infection under control in the heterosexual community, even without universal voluntary testing.5ConclusionsMuch world effort properly is being focused where the disease is rampant, as in opposite-sex communities in many African nations6 as well as male same-sex communities everywhere.7 Critical attention must be continued in these sensitive populations, but attention throughout the general population is called for as an additional pre-emptive measure. Our results illustrate how expanded efforts in low-prevalence heterosexual communities throughout the developed world could moderate the expanding infection there, arrest it before it reaches run-away levels, and conceivably cause it to decline and eventually vanish from the general population.
P1-S6.04 Education and lifetime risk of HIV infection in Manicaland, Zimbabwe
Authors: Robertson L , Mushati P , Eaton J , Schumacher C , Gregson S , Nyamukapa C 
Published: July 2011

BackgroundThere is evidence that attendance at school is protective against HIV among young people in South Africa. Further work is required to investigate the effect of education on the life-time risk of HIV in sub-Saharan Africa. In this paper, we have examined the association between education and HIV infection/sexual risk behaviour among men and women of different ages in Zimbabwe.MethodsThe effects of education level (none or primary only; secondary or higher) on prevalent HIV infection and sexual risk behaviours among young people of school age (15–21 years) and older adults (22–54 years) were investigated using data from four rounds of an open cohort study collected between 1999 and 2008 in Manicaland, Eastern Zimbabwe. Multivariate regression models were used to investigate the independent effects of education, marriage and wealth.ResultsSchool-aged men, interviewed in 1999/2000, with secondary or higher education had significantly reduced risk of HIV infection compared to those with none or primary education only (adjusted OR=0.35; p=0.011). For older men, the effect of education level was not significantly associated with HIV risk (adjusted OR=1.17; p=0.125). For those interviewed in 2006/2008, education level was not found to be independently associated with HIV infection among school-aged or older men. At both time points, marital status and living in a town were independent risk factors for HIV among older men. Among women interviewed in 1999/2000, adjusted models indicate that a higher level of education had a significant protective effect for school-aged (adjusted OR=0.64; p=0.023) and older (adjusted OR=0.80; p=0.017) women. For those interviewed in 2006/2008, a higher level of education level was protective among school-aged (adjusted OR=0.56; p=0.040) but not older (adjusted OR=0.99; p=0.940) women. Marital status was an independent risk factors for HIV infection fort women of all ages.ConclusionsThere is evidence that secondary or higher education is protective against HIV infection among school-aged people in Zimbabwe, particularly women. Among older men, education does not appear to be protective against HIV. In 1999/2000, secondary or higher education was protective against HIV among older women. However, in 2006/2008, this protective effect was reduced. Further work to calculate the lifetime cumulative risk of HIV infection by education level, in this population, will be conducted.