Edge-based network models, especially those based on bond percolation methods, can be used to model disease transmission on complex networks and accommodate social heterogeneity while keeping tractability. Here we present an application of an edge-based network model to the spread of syphilis in the Kingston, Frontenac and Lennox & Addington region of southeastern Ontario, Canada. We compared the results of using a network-based susceptible-infectious-recovered (SIR) model to those generated from using a traditional mass action SIR model. We found that the network model yields very different predictions, including a much lower estimate of the final epidemic size. We also used the network model to estimate the potential impact of introducing a rapid syphilis point of care test and treatment intervention strategy that has recently been implemented by the public health unit to mitigate syphilis transmission.

Since 1979, the National Network of Sexually Transmitted Disease (STD) Clinical Prevention Training Centers (NNPTC) has provided state-of-the-art clinical and laboratory training for STD prevention across the United States. This article provides an overview of the history and activities of the NNPTC from its inception to present day, and emphasizes the important role the network continues to play in maintaining a high-quality STD clinical workforce. Over time, the NNPTC has responded to changing STD epidemiological patterns, technological advances, and increasing private-sector care-seeking for STDs. Its current structure of integrated regional and national training centers allows NNPTC members to provide dynamic, tailored responses to STD training needs across the country.

Malaria in pregnancy is associated with increased risk for both maternal and neonatal adverse outcomes, notably low birthweight and neonatal mortality.1 Since 2004, following studies that showed that intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) reduced the risk of these adverse events,2 the World Health Organization (WHO) recommended IPTp-SP for all areas in Africa with moderate-to-high malaria transmission.3 IPTp-SP is associated with significant reductions in low birthweight, with a protective efficacy of approximately 26% in an analysis of national survey data from 32 countries.4 This impact has been presumed to be a result of the antimalarial effects of SP. Because resistance to SP has increased, particularly in eastern and southern Africa, SP is no longer recommended for treatment of acute malaria illness, even in combination with artemisinins. Despite this, even in areas where the efficacy of SP to clear parasitemia has clearly decreased, IPTp-SP has continued to show benefit for preventing low birthweight.5 Moreover, no other antimalarials have yet been shown to be an ideal replacement for SP for IPTp. Studies evaluating potential alternative IPTp regimens have had mixed outcomes on birthweight,6,7 leading to the hypothesis that SP may exert some of its effect through antibacterial or anti-inflammatory actions.6 In Lusaka, Zambia, where malaria parasite prevalence is < 1%, Stoner and others show that among human immunodeficiency virus (HIV)-positive women, receipt of IPTp-SP was associated with a dose-dependent reduction in the risk of low birthweight, as well as an increase in gestational age, further suggesting a mechanism other than antimalarial activity as an explanation for a reduced risk of low birthweight among women receiving IPTp-SP during pregnancy (Stoner and others).

PURPOSE: To examine associations between phthalate metabolite urinary concentrations during early pregnancy and blood glucose levels obtained at the time of screening for gestational diabetes mellitus (GDM). METHODS: Upon initiation of prenatal care, women with a mean gestational age of 12.8 weeks were recruited for a study of environmental chemical exposures (n=110) and provided a spot urinary specimen. Blood glucose concentrations (mg/dl) were obtained from the electronic medical record for those patients who did not experience a pregnancy loss and did not transfer care to another facility prior to glucose screening (n=72). Urinary concentrations of nine phthalate metabolites and creatinine were measured at the US Centers for Disease Control and Prevention. Associations between tertiles of phthalate metabolites concentrations and blood glucose levels were estimated using linear regression. RESULTS: Compared to pregnant women in the lowest concentration tertile, women with the highest urinary concentrations (≥3rd tertile) of mono-iso-butyl phthalate (tertile: ≥15.3mug/l, beta=-18.3, 95% CI: -35.4, -1.2) and monobenzyl phthalate (tertile: ≥30.3mug/l, beta=-17.3, 95% CI: -34.1, -0.4) had lower blood glucose levels at the time of GDM screening after adjustment for urinary creatinine and demographic covariates. CONCLUSION: Because maternal glucose levels increase during pregnancy to provide adequate nutrition for fetal growth and development, these findings may have implications for fetal health. However, given the limitations of our study, findings should be interpreted cautiously.

BACKGROUND: At sexually transmitted disease (STD) clinics, advances in testing technology coupled with increasing demands and diminishing resources have promoted the use of testing-only visits (clinic visits with testing for STDs but no full examination) to meet increasing demands for STD services. OBJECTIVES: The aims of the present study were to estimate the prevalence of STD diagnoses that could become "missed diagnoses" if patients would use testing-only visits and to examine patient characteristics associated with these potential missed diagnoses. METHODS: We conducted a self-administered survey of STD-related symptoms and sexual risk behaviors in patients seeking routine clinical care at 3 STD clinics. Medical charts were abstracted to estimate the prevalence of viral STDs, trichomoniasis, and other diagnoses from standard clinical services that could become missed diagnoses. RESULTS: Of 2582 patients included, the median age was 24 years and 50% were women. In women, overall, 3.2% were diagnosed as having a viral STD; 9.6%, trichomoniasis; and 41.0%, vulvovaginal candidiasis or symptomatic bacterial vaginosis. The prevalence of these potential missed diagnoses varied by patient characteristics, but in women who reported no symptoms, the prevalence of trichomoniasis was still 6.3%. In men, 19.3% received a diagnosis of urethritis but tested negative for both gonorrhea and chlamydia; this prevalence varied from 15.7% in those who reported no symptoms to 32.6% in those who reported malodor. CONCLUSIONS: A high proportion of STD clients received diagnoses from standard care visits that would be missed by testing-only visits. When patients, even those asymptomatic, use testing-only visits, missed diagnoses of STDs or related genital tract conditions can be substantial. The potential disadvantages of testing-only visits should be weighed against the advantages of such visits.

BACKGROUND: Few data exist on potential harms of chlamydia screening. We assessed the psychosocial impact of receiving a positive Chlamydia trachomatis test result. METHODS: We prospectively studied women ≥16 years of age undergoing chlamydia testing in 2 Midwestern family planning clinics. We surveyed women at baseline and about 1 month after receiving test results, using 9 validated psychosocial scales/subscales and chlamydia-specific questions. Changes in scale scores were calculated for each woman. Mean percent changes in scores for chlamydia-positive and -negative women were compared using a t test. RESULTS: We enrolled 1807 women (response rate, 84%). Of the 1688 women with test results, 149 (8.8%) tested positive. At follow-up, chlamydia-positive women (n = 71) had a 75% increase in anxiety about sexual aspects of their life on the Multidimensional Sexual Self-Concept Questionnaire (P < 0.001), significantly greater than the 26% increase among 280 randomly selected chlamydia-negative women (P = 0.02). There were no differences for the other 8 scales/subscales, including general measures of anxiety, depression, and self-esteem. Chlamydia-positive women were more likely than chlamydia-negative women to be "concerned about chlamydia" (80% vs. 40%, P < 0.001) and to report breaking up with a main partner (33% vs. 11%, P < 0.001) at follow-up. Women testing positive reported a range of chlamydia-specific concerns. CONCLUSIONS: Chlamydia-positive women had significant increases in anxiety about sex and concern about chlamydia, but did not have marked changes in more general measures of psychosocial well-being about 1 month after diagnosis. Chlamydia diagnoses were associated with some disruption of relationships with main partners. Chlamydia-specific concerns may guide counseling messages to minimize psychosocial impact.

OBJECTIVE: To determine whether the use of home-based, self-obtained vaginal swabs among women who were treated for Chlamydia infection can increase rescreening rates in comparison with clinic-based rescreening, and to identify subgroups in which rescreening could be enhanced using self-obtained vaginal swabs. METHODS: Two randomized trials were conducted: one with enrollment in sexually transmitted disease (STD) clinics and the other in family planning clinics. Study participants were recruited from STD (n=880) and family planning clinics (n=412) in three cities. Females aged 16 years or older who were treated for Chlamydia infection were randomly assigned to the home group (swab collection kits mailed to home) or the clinic group (made clinic appointments) for rescreening at 3 months after treatment, with reminder calls about 2 weeks before the scheduled rescreening date. RESULTS: Groups were similar with respect to age and other demographic characteristics. Women assigned to the home group had higher rescreening rates than those in the clinic group. In STD clinics, rescreening rates were 26.7% (home) compared with 19.1% (clinic) (P=.01). In family planning clinics, rescreening rates were 40.8% (home) compared with 20.7% (clinic) (P<.001). Among women reached by reminder calls, rescreening rates were also significantly higher in the home groups: 43.5% compared with 33.0% in STD clinic participants and 59.2% compared with 37.8% in family planning clinic participants (both P<.05). The rates of reinfection ranged from 12.9% to 19.4%, and the differences by group were not statistically significant (P≥.3). CONCLUSION: In STD and family planning clinics, use of home-based, self-obtained vaginal swabs resulted in significant increases in rescreening rates compared with rescreening in the clinic. Home-based specimen collection can be an alternative to clinic-based rescreening for Chlamydia infection in women. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, www.clinicaltrials.gov, NCT 00132457. LEVEL OF EVIDENCE: I.

OBJECTIVES: To meet the need for services at sexually transmitted infection (STI) clinics, self-obtained vaginal (SOV) swabs or first-catch urine (FCU) samples collected at a clinic visit have been proposed as an alternative approach for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) screening. The purpose of this clinic-based survey was to determine if non-invasive clinic-based SOV swabs and FCU samples for CT and GC screening are acceptable replacements for a traditional provider visit. METHODS: Patients seen at STI clinics in three US cities completed a self-administered survey of preferences for methods of CT and GC screening under hypothetical circumstances. RESULTS: A total of 2887 participants completed a self-administered questionnaire that contained multiple-choice questions about their preference. If there was a hypothetical long clinic wait, 58% of the survey participants preferred to wait to see a doctor. If the clinic had to turn patients away, 41% of patients preferred to come back the next business day and 46% preferred to self-collect a sample. The percentages were similar across site, demographic and clinical groups. CONCLUSIONS: Clinic-based self-collected specimens for CT and GC screening were not preferred by most patients who participated in this survey. The findings indicate that more detailed information about self-collection practices must be provided for patients to adopt this new approach.

Chlamydia trachomatis (CT) is the most common sexually transmitted bacterial infection reported in the United States.1 Most recurrent CT infections in women in the first few months after treatment are due to reinfection by an untreated male partner.2 The Centers for Disease Control and Prevention (CDC) recommend that all persons with a diagnosis of CT infection be candidates for partner services. Patient-delivered partner therapy (PDPT), where patients are given medication to deliver to each sex partner, is an important strategy for partner services when resources are limited.3 PDPT has been shown to reduce the risk for reinfection with CT.4,5 This study aimed to describe the partner treatment preference of patients visiting urban sexually transmitted disease (STD) clinics. | Men and women who visited STD clinics in 3 US cities—New Orleans, LA; Jackson, MS; and St. Louis, MO—between June and September 2008 were invited to complete a short survey before being seen at the clinic. The survey was piloted at each study clinic before its implementation. The study was approved by institution review boards at each institution and the CDC and was exempt from informed consent. A total of 2887 individuals completed the survey. Over 90% of participants were blacks, 49.7% were female, and the mean age was 27.1 year (men: 28.4, women: 25.9).

BACKGROUND AND OBJECTIVES: Understanding the time course of sexual partnerships is important for understanding sexual behaviour, transmission risks for sexually transmitted infections (STI) and development of mathematical models of disease transmission. STUDY DESIGN: The authors describe issues and biases relating to censoring, truncation and sampling that arise when estimating partnership duration. Recommendations for study design and analysis methods are presented and illustrated using data from a sexual-behaviour survey that enrolled individuals from an adolescent-health clinic and two STD clinics. Survey participants were queried, for each of (up to) four partnerships in the last 3 months, about the month and year of first sex, the number of days since last sex and whether partnerships were limited to single encounters. Participants were followed every 4 months for up to 1 year. RESULTS: After adjustment for censoring and truncation, the estimated median duration of sexual partnerships declined from 9 months (unadjusted) to 1.6 months (adjusted). Similarly, adjustment for censoring and truncation reduced the bias in relative risks for the effect of age in a Cox model. Other approaches, such as weighted estimation, also reduced bias in the estimated duration distribution. CONCLUSION: Methods are available for estimating partnership duration from censored and truncated samples. Ignoring censoring, truncation and other sampling issues results in biased estimates.