Characterizing the syphilis epidemic among men who have sex with men in Lima, Peru to identify new treatment and control strategies

Study on the influence of syphilis on the outcome of frozen-thawed embryo transfer in infertility patients

Objective

In this study, the effect of in vitro Fertilization-Embryo Transfer (IVF-ET) on the clinical outcome of patients with syphilis infertility during resuscitation cycle.

Methods

A retrospective single-center method was adopted. This study included 4430 pairs of infertile patients who underwent syphilis detection. The influence of the syphilis freeze-thaw embryos transplantation outcome was studied in the patients with infertility by comparing the general clinical characteristics of patients (age, years of infertility, body mass index (BMI), basal follicle stimulating hormone (FSH), serum basal estradiol (Estradiol, E2), transplanted intimal thickness, the number of embryos transferred) and the clinical pregnancy (biochemical pregnancy rate, clinical pregnancy rate, implantation rate, live birth rate and abortion rate).

Results

Firstly, in the clinical outcome of one frozen-thawed embryos transfer, the live birth rate of the woman's syphilis-infected group was lower than that of the uninfected group (71.3 % vs. 50.0 %), while the abortion rate was higher than that of the uninfected group (7.8 % vs. 26.7 %), and there was a statistical difference (P < 0.05), and there was no statistical difference in other indicators between other groups (P > 0.05). Secondly, in the clinical outcome of two frozen-thawed embryos transfers, the biochemical pregnancy rate (61.3 % vs. 28.6 %) and clinical pregnancy rate (42.9 % vs. 14.3 %) of the group which was infected with syphilis alone were lower than those of the uninfected group (P < 0.05), and other indicators among the other groups showed no statistical difference (P > 0.05). Thirdly, in the clinical outcomes of frozen-thawed embryos transfer three times or more, there was no significant difference in the clinical indicators between the syphilis infertility patients and the non-infected infertility patients (P > 0.05).

Conclusion

When the syphilis infertility patients and the non-infected infertile patients underwent IVF-ET treatment for the first time, the live birth rate and abortion rate of the syphilis group were significantly different (P < 0.05). In the outcome of two transplants, the biochemical pregnancy rate and clinical Pregnancy rates were significantly reduced so patients with syphilis infertility who undergo IVF-ET should be informed about the risk of adverse clinical outcomes.

Extra-genital Neisseria gonorrhoeae infections with genetic mutations conferring ciprofloxacin resistance among men who have sex with men and transgender women in Lima, Peru

BACKGROUND

The increasing prevalence of drug-resistant Neisseria gonorrhoeae (NG) infections has caused great concern. Ciprofloxacin remains the empiric antimicrobial recommended to treat NG infections in Peru disregarding the susceptibility profile of circulating NG strains. We report the prevalence of individuals infected with NG strains presenting mutations in the gyrA gene that confers ciprofloxacin resistance.

METHODS

We conducted a descriptive study assessing extragenital swab samples collected from a cohort of men who have sex with men and transgender women in Lima, Peru. Anal and pharyngeal NG positive swabs for Aptima Combo 2 assay (Hologic Inc., USA) were used for DNA extraction. We performed TaqMan real time PCR assays to detect a point mutation at codon Ser91 of the gyrase A (gyrA) gene.

RESULTS

From 156 individuals who had at least one positive sample for NG reported by the Aptima assay, 80 individuals had at least one amplified DNA for the gyrA gene. We found that 67 of them (84.0%) were infected with a gyrA-mutated NG strain at the Ser91 codon.

CONCLUSIONS

We report a high prevalence of gyrA mutation conferring ciprofloxacin resistance among individuals with extragenital NG infection. Empirical treatment of NG needs to be urgently updated in Peru in concordance with international guidelines.

The Application of Cytokine Expression Assays to Differentiate Active From Previously Treated Syphilis

To investigate the role of serum cytokine assays to distinguish between active from treated syphilis among serofast patients, we recruited individuals into a prospective cohort study. Participants underwent routine syphilis screening. We selected specimens from a majority cohort of serofast participants with treated and active syphilis. We analyzed specimens with a 62-cytokine multiplex bead-based enzyme-linked immunosorbent assay. Cytokines, brain-derived neurotrophic factor and tumor necrosis factor β, were most predictive. We built a decision tree that was 82.4% accurate, 100% (95% confidence interval, 82%-100%) sensitive, and 45% (18%-75%) specific. Our decision tree differentiated between serum specimens from serofast participants with treated syphilis versus active syphilis.

Investigation of syphilis immunology and Treponema pallidum subsp. pallidum biology to improve clinical management and design a broadly protective vaccine: study protocol

BACKGROUND

The syphilis epidemic continues to cause substantial morbidity and mortality worldwide, particularly in low- and middle-income countries, despite several recent disease control initiatives. Though our understanding of the pathogenesis of this disease and the biology of the syphilis agent, Treponema pallidum subsp. pallidum has improved over the last two decades, further research is necessary to improve clinical diagnosis and disease management protocols. Additionally, such research efforts could contribute to the identification of possible targets for the development of an effective vaccine to stem syphilis spread.

METHODS

This study will recruit two cohorts of participants with active syphilis infection, one with de novo infection, one with repeat infection. Whole blood specimens will be collected from each study participant at baseline, 4, 12, 24, 36, and 48 weeks, to track specific markers of their immunological response, as well as to compare humoral reactivity to Treponema pallidum antigens between the two groups. Additionally, we will use serum specimens to look for unique cytokine patterns in participants with early syphilis. Oral and blood samples, as well as samples from any syphilitic lesions present, will also be collected to sequence any Treponema pallidum DNA found.

DISCUSSION

By furthering our understanding of syphilis pathogenesis and human host immune response to Treponema pallidum, we will provide important data that will help in development of new point-of-care tests that could better identify active infection, leading to improved syphilis diagnosis and management. Findings could also contribute to vaccine development efforts.

The development of an online risk calculator for the prediction of future syphilis among a high-risk cohort of men who have sex with men and transgender women in Lima, Peru

Background Syphilis incidence worldwide has rebounded since 2000, particularly among men who have sex with men (MSM). A predictive model for syphilis infection may inform prevention counselling and use of chemoprophylaxis.

METHODS

Data from a longitudinal cohort study of MSM and transgender women meeting high-risk criteria for syphilis who were followed quarterly for 2 years were analysed. Incidence was defined as a four-fold increase in rapid plasma reagin (RPR) titres or new RPR reactivity if two prior titres were non-reactive. Generalised estimating equations were used to calculate rate ratios (RR) and develop a predictive model for 70% of the dataset, which was then validated in the remaining 30%. An online risk calculator for the prediction of future syphilis was also developed.

RESULTS

Among 361 participants, 22.0% were transgender women and 34.6% were HIV-infected at baseline. Syphilis incidence was 19.9 cases per 100-person years (95% confidence interval (CI) 16.3-24.3). HIV infection (RR 2.22; 95% CI 1.54-3.21) and history of syphilis infection (RR 2.23; 95% 1.62-3.64) were significantly associated with incident infection. The final predictive model for syphilis incidence in the next 3 months included HIV infection, history of syphilis, number of male sex partners and sex role for anal sex in the past 3 months, and had an area under the curve of 69%. The online syphilis risk calculator based on those results is available at: www.syphrisk.net.

CONCLUSIONS

Using data from a longitudinal cohort study among a population at high risk for syphilis infection in Peru, we developed a predictive model and online risk calculator for future syphilis infection. The predictive model for future syphilis developed in this study has a moderate predictive accuracy and may serve as the foundation for future studies.

Cytokine expression in Treponema pallidum infection

BACKGROUND

Current syphilis tests cannot distinguish between active and past syphilis among patients with serofast rapid plasma reagin (RPR) titers. We investigated whether cytokine profiles might provide insight in the differentiation of active and treated syphilis.

METHODS

We collected quarterly serum samples from participants at risk for incident syphilis in a prospective cohort study of men and male-to-female transgender women. We defined incident syphilis as a new RPR titer ≥ 1:8 or a fourfold increase from a prior RPR titer and a positive Treponema pallidum particle agglutination assay. We measured cytokine expression using a 63-multiplex bead-based Luminex assay (eBiosciences/Affymetrix, San Diego, California, USA). We used tertile bins and Chi square tests to identify differences in proportions of cytokines between samples from patients with active and treated syphilis. We constructed a network of cytokine profiles from those findings. We used R software (R version 3.4.1, R, Vienna, Austria) to fit models.

RESULTS

We identified 20 pairs of cytokines (out of 1953 possible pairs) that differed between active and treated syphilis. From those, we identified three cytokine networks of interest: an Eotaxin-Rantes-Leptin network, a Mig-IL1ra-Trail-CD40L network, and an IL12p40-IL12p70 network.

CONCLUSIONS

Differences in cytokine profiles are present among men and male-to-female transgender women with active and treated syphilis. Cytokine assays may be a potentially useful tool for identifying active syphilis among patients with serologic syphilis reactivity.

The Relationship Between Risk Perception and Frequency of HIV Testing Among Men Who Have Sex with Men and Transgender Women, Lima, Peru

HIV infections in Peru are concentrated among men who have sex with men (MSM) and transgender women (TW). HIV testing rates among them remain low, delaying entrance into care. We assessed the prevalence of frequent HIV testing (at least every 6 months) and associated factors among 310 MSM and TW who attend sexual health clinics in Lima, Peru, and who reported that they were HIV seronegative or unaware of their status. Only 39% of participants tested frequently, and 22% had never tested; 29% reported that they were at low or no risk for acquiring HIV. Reporting low or no risk for acquiring HIV was associated with frequent testing (adjusted prevalence ratio [aPR] = 1.53, 95% CI 1.13-2.08); those reporting unprotected anal sex were less likely to test frequently (aPR = 0.66, 95% CI 0.50-0.87). HIV prevalence was 12% and did not vary by risk perception categories. This at-risk population tests infrequently and may not understand the risk of having unprotected sex.

Laboratory Evaluation of a Smartphone-Based Electronic Reader of Rapid Dual Point-of-Care Tests for Antibodies to Human Immunodeficiency Virus and Treponema pallidum Infections

BACKGROUND

Dual point-of-care tests for antibodies to human immunodeficiency virus (HIV) and Treponema pallidum allow for same-day testing and treatment and have been demonstrated to be cost-effective in preventing the adverse outcomes of HIV infection and syphilis. By recording and transmitting data as they are collected, electronic readers address challenges related to the decentralization of point-of-care testing.

METHODS

We evaluated a smartphone-based electronic reader using 201 sera tested with 2 dual rapid tests for detection of antibodies to HIV and T. pallidum in Los Angeles, USA, and Lima, Peru. Tests were read both visually and with the electronic reader. Enzyme immunoassay followed by Western blot and T. pallidum particle agglutination were the reference tests for HIV and T. pallidum, respectively.

RESULTS

The sensitivities of the 2 rapid tests for detection of HIV were 94.1% and 97.0% for electronic readings. Both tests had a specificity of 100% for detection of HIV by electronic reading. The sensitivities of the 2 rapid tests for detection of T. pallidum were 86.5% and 92.4% for electronic readings. The specificities for detection of T. pallidum were 99.1% and 99.0% by electronic reading. There were no significant differences between the accuracies of visual and electronic readings, and the performance did not differ between the 2 study sites.

CONCLUSIONS

Our results show the electronic reader to be a promising option for increasing the use of point-of-care testing programs.

Treponema pallidum pallidum Genotypes and Macrolide Resistance Status in Syphilitic Lesions among Patients at 2 Sexually Transmitted Infection Clinics in Lima, Peru

We report the circulating genotypes and the frequency of macrolide-resistance patterns among Treponema pallidum pallidum DNA isolated from syphilitic lesions from patients who attended 2 sexual health clinics in Lima, Peru. We implemented and used a molecular typing scheme to describe local T. pallidum pallidum strains. Among 14 specimens, subtype 14d/f was the most prevalent strain in 7 fully typed T. pallidum DNA specimens obtained from men who have sex with men and transgender women presenting with chancre-like lesions. No macrolide-resistance mutations were found in T. pallidum DNA from 10 lesions.

Demographics, Behaviors, and Sexual Health Characteristics of High Risk Men Who Have Sex With Men and Transgender Women Who Use Social Media to Meet Sex Partners in Lima, Peru

BACKGROUND

Men who have sex with men (MSM) and transgender women (TW) in Peru bear a disproportionate burden of human immunodeficiency virus (HIV) and sexually transmitted infections (STIs). In a context of quickly expanding communication technology, increasing numbers of MSM and TW are using social media applications to seek sex partners. Understanding social media users and their sex partnering practices is needed to update HIV and STI prevention programming.

METHODS

In Lima, Peru, 312 MSM and 89 TW from 2 STI clinics underwent HIV and STI testing and participated in a survey of demographics, behaviors, sexual health, and social media practices. χ, t tests, and Wilcoxon Mann-Whitney tests were used to compare those with and without recent social media sex partners.

RESULTS

Men who have sex with men with social media sex partners were younger, more educated, and more likely to identify as gay. They were significantly more likely to report greater numbers of sex partners, including anonymous sex partners; sex in higher-risk venues, orgies, and have rectal Neisseria gonorrhoeae or Chlamydia trachomatis infection. Transgender women with social media sex partners were also younger, more likely to participate in sex work, and have a lower rate of rapid plasma reagin positivity or history of syphilis. Participants reported using several social media sites including sexual hook-up applications, websites for gay men, pornographic websites, and chat sites, but the most common was Facebook.

CONCLUSIONS

Prevention strategies targeting Peruvian MSM and TW who use social media are needed to address higher-risk sexual behavior and the high burden of STIs.

High incidence of extra-genital gonorrheal and chlamydial infections among high-risk men who have sex with men and transgender women in Peru

Extra-genital Neisseria gonorrhoeae and Chlamydia trachomatis infections are associated with antimicrobial resistance and HIV acquisition. We analyzed data from a cohort of men who have sex with men (MSM) and transgender women followed quarterly for two years in Peru. Incident cases were defined as positive N. gonorrhoeae or C. trachomatis nucleic acid tests during follow-up. Repeat positive tests were defined as reinfection among those with documented treatment. We used generalized estimating equations to calculate adjusted incidence rate ratios (aIRRs). Of 404 participants, 22% were transgender. Incidence rates of rectal N. gonorrhoeae and C. trachomatis infection were 28.1 and 37.3 cases per 100 person-years, respectively. Incidence rates of pharyngeal N. gonorrhoeae and C. trachomatis infection were 21.3 and 9.6 cases per 100 person-years, respectively. Incident HIV infection was associated with incident rectal (aIRR = 2.43; 95% CI 1.66-3.55) N. gonorrhoeae infection. Identifying as transgender versus cisgender MSM was associated with incident pharyngeal N. gonorrhoeae (aIRR = 1.85; 95% CI 1.12-3.07) infection. The incidence of extra-genital N. gonorrhoeae and C. trachomatis infections was high in our population. The association with incident HIV infection warrants evaluating the impact of rectal N. gonorrhoeae screening and treatment on HIV transmission.

Do Subjective Alcohol Screening Tools Correlate with Biomarkers Among High-Risk Transgender Women and Men Who Have Sex with Men in Lima, Peru?

Alcohol abuse can influence sexual risk behavior; however, its measurement is not straightforward. This study compared self-reported alcohol use, via the AUDIT and CAGE, with levels of phosphatidylethanol (Peth), a phospholipid biomarker that forms with chronic, heavy drinking, among high-risk MSM and TW in Lima, Peru. Chi square, Fisher's exact, Wilcoxon ranksum tests compared the instruments. Receiver operating curves determined sensitivity and specificity of the self-reported measures. Among 69 MSM and 17 TW, PEth was positive for 86% (95% CI 77-93%) of participants, while 67% reported binge-drinking in the last 2 weeks. The AUDIT classified 25% as hazardous drinkers while CAGE identified 6% as problem drinkers. Self-reported binge drinking was more sensitive than the AUDIT for PEth positivity (71% vs. 27%, p = 0.022). Among high-risk MSM and TW in Lima, validated, self-report measures of alcohol abuse underestimated biological measures. Further research correlating bio-markers and self-reported alcohol abuse measures is needed.

Transient aortitis documented by positron emission tomography in a case series of men and transgender women infected with syphilis

OBJECTIVES

Syphilis infection persists globally contributing to preventable and treatable morbidity and mortality. How extensive early syphilis disseminates is unknown. To better understand the relationship between early syphilis infection and inflammation over time, our study enrolled six individuals recently infected with syphilis for sequential positron emission tomography (PET) scans.

METHODS

We evaluated a case series of six individuals with high syphilis titres (two secondary, two early latent and two latent, unknown duration, but with high titre) who received sequential PET scans to assess inflammation over time and its response to treatment.

RESULTS

At time of PET scan, four of the six individuals were co-infected with HIV. One of the four was not on antiretroviral therapy and three of the four were not virally suppressed (viral load of >400 copies/mL). Baseline rapid plasma reagin (RPR) titres ranged from 1:64 to 1:256 (four of the six participants had prior non-reactive RPR results). Five of the six participants had mild to intense hypermetabolic PET scan activity consistent with cervical (n=5), axillary (n=4), inguinal (n=5) and retroperitoneal (n=1) adenopathy. Mild hypermetabolic activity in the thoracic aortic wall, suggesting aortitis, was present among the same five participants and resolved within 30 days for four of the five participants and 60 days for the other participant. However, widespread lymphadenopathy remained present in PET scans up to 3 months following treatment in two participants. We did not find any abnormal PET scan activity of the central nervous system.

CONCLUSION

We found abnormal aortic wall PET scan activity suggesting aortitis to be common in a case series of patients with early syphilis. In research settings, PET scans may be a sensitive tool to monitor inflammation associated with syphilis.

The PICASSO Cohort: baseline characteristics of a cohort of men who have sex with men and male-to-female transgender women at high risk for syphilis infection in Lima, Peru

BACKGROUND

Men who have sex with men (MSM) and male-to-female transgender women (transwomen) are disproportionately at risk of syphilis infection in Peru.

METHODS

From 2013 to 2014, MSM and transwomen seeking human immunodeficiency virus (HIV) or sexually transmitted infection (STI) testing and/or treatment were recruited into a 2-year observational cohort study to determine predictors of recently acquired syphilis infection (defined as a rapid plasma reagin [RPR] titer ≥1:16 and a reactive treponemal antibody test) in Lima, Peru. At baseline, interviewers collected sociodemographic, behavioral, and medical characteristics from participants. All cohort participants were tested for syphilis, HIV, Chlamydia trachomatis (CT), and Neisseria gonorrhoeae (NG) infection. Using cross-sectional analyses, bivariate and multivariate models were used to determine factors associated with recently acquired syphilis infection and calculate adjusted prevalence ratios.

RESULTS

We recruited 401 participants, 312 MSM and 89 transwomen, with median ages of 29.0 and 32.5 years old (interquartile ranges: 23.3, 37.4 and 27.2, 39.5, respectively). The prevalence of recently acquired syphilis infection at baseline was 16.8% for MSM and 6.7% for transwomen. Among MSM and transwomen, 30.1 and 33.7% were infected with HIV, 18.6 and 24.7% were infected with CT, and 14.2 and 19.1% were infected with NG, respectively. Co-infection rates among MSM with recently acquired syphilis infection included: 44.2% with HIV, 40.4% with CT (32.7% with anal CT and 7.7% with pharyngeal CT), and 19.2% with NG (11.5% with anal NG and 7.7% with pharyngeal NG). Co-infection rates among transwomen with recently acquired syphilis infection included: 66.7% with HIV, 0% with CT, and 16.7% with anal NG. In multivariate analysis among the entire cohort, recently acquired syphilis infection was independently associated with younger age (adjusted prevalence ratio [aPR] = 0.96, 95% confidence interval [CI] = 0.93-0.99), receptive role during anal sex (aPR = 2.56, 95% CI = 1.05-6.25), prior HIV diagnosis (aPR = 1.70, 95% CI = 1.11-2.61), anal CT or NG infection (aPR = 1.69, 95% CI = 1.09-2.60), and prior syphilis diagnosis (aPR = 3.53, 95% CI = 2.20-5.68).

CONCLUSIONS

We recruited a cohort of MSM and transwomen who had a high prevalence of recently acquired syphilis infection in Lima, Peru. Recently acquired syphilis infection was associated with socio-demographic characteristics, sexual risk, and sexually transmitted co-infections.

Toward a Realistic Modeling of Epidemic Spreading with Activity Driven Networks

Models of epidemic spreading are widely used to predict the evolution of an outbreak, test specific intervention scenarios, and steer interventions in the field. Compartmental models are the most common class of models. They are very effective for qualitative analysis, but they rely on simplifying assumptions, such as homogeneous mixing and time scale separation. On the other end of the spectrum, detailed agent-based models, based on realistic mobility pattern models, provide extremely accurate predictions. However, these models require significant computing power and are not suitable for analytical treatment. Our research aims at bridging the gap between these two approaches, toward time-varying network models that are sufficiently accurate to make predictions for real-world applications, while being computationally affordable and amenable to analytical treatment. We leverage the novel paradigm of activity driven networks (ADNs), a particular type of time-varying network that accounts for inherent inhomogeinities within a population. Starting from the basic incarnation of ADNs, we expand on the framework to include behavioral factors triggered by health status and spreading awareness. The enriched paradigm is then utilized to model the 2014–2015 Ebola Virus Disease (EVD) spreading in Liberia, and perform a what-if analysis on the timely application of sanitary interventions in the field. Finally, we propose a new formulation, which is amenable to analytical treatment, beyond the mere computation of the epidemic threshold.

Probable Syphilitic Aortitis Documented by Positron Emission Tomography

Positron emission tomography (PET) has been used to aid in diagnosis of inflammatory and infectious disease. We describe the case of a patient with early latent syphilis with increased metabolic activity along the aorta detected via PET, suggesting probable aortitis. Three months after treatment, the PET showed apparent resolution of the aortitis.

Factors associated with previously undiagnosed human immunodeficiency virus infection in a population of men who have sex with men and male-to-female transgender women in Lima, Peru

The aim of the study was to identify factors associated with undiagnosed human immunodeficiency virus (HIV) infection among men who have sex with men (MSM) and male-to-female transgender women in Lima, Peru.We analyzed characteristics of 378 MSM and transgender women recruited from 2 sexually transmitted infection (STI) clinics in Lima, Peru. Descriptive analyses compared: (A) HIV-uninfected, (B) previously undiagnosed HIV-infected, and (C) previously diagnosed HIV-infected participants. Multivariable logistic regression models identified: (1) correlates of previously undiagnosed HIV-infection among participants thought to be HIV-uninfected (B vs A); and (2) correlates of previously undiagnosed HIV-infection among HIV-infected participants (B vs C). Subanalysis identified correlates of frequent HIV testing among participants thought to be HIV-uninfected.Among participants, 31.0% were HIV-infected; of those, 35.0% were previously undiagnosed. Among participants thought to be HIV-uninfected (model 1), recent condomless receptive anal intercourse and last HIV test being over 1-year ago (compared to within the last 6-months) were associated with increased odds of being previously undiagnosed HIV-infected (adjusted odds ratio [aOR] = 2.43, 95% confidence interval [95%CI] = 1.10-5.36; aOR = 2.87, 95%CI = 1.10-7.53, respectively). Among HIV-infected participants (model 2), recent condomless receptive anal intercourse was again associated with previously undiagnosed HIV-infection (aOR = 2.54, 95%CI = 1.04-6.23). Achieving post-secondary education and prior syphilis infection were associated with lower odds of having previously undiagnosed HIV-infection (aOR = 0.35, 95%CI = 0.15-0.81; aOR = 0.32, 95%CI = 0.14-0.75, respectively).Reporting semiannual testing was associated with higher educational attainment, identifying as a transgender woman, or reporting a history of syphilis (aOR = 1.94, 95%CI = 1.11-3.37; aOR = 2.40, 95%CI = 1.23-4.70; aOR = 2.76, 95%CI = 1.62-4.71, respectively). Lower odds of semiannual testing were associated with recent condomless insertive anal intercourse or reporting a moderate or high self-perceived risk of acquiring HIV (aOR = 0.56, 95%CI = 0.33-0.96; aOR = 0.32, 95%CI = 0.18-0.59 and aOR = 0.43, 95%CI = 0.21-0.86, respectively).In our study, undiagnosed HIV-infection was associated with recent condomless receptive anal intercourse, infrequent HIV testing, lower education, and absence of prior syphilis diagnosis. Infrequent HIV testing was associated with lower education, not identifying as transgender, recent condomless insertive anal intercourse, absence of prior syphilis diagnosis, and higher self-perceived risk of HIV. Further efforts to decrease HIV transmission and increase HIV-serostatus awareness should be directed towards effectively promoting condom use and frequent HIV testing, integrated with STI management.

HIV self-testing in Peru: questionable availability, high acceptability but potential low linkage to care among men who have sex with men and transgender women

HIV status awareness is key to prevention, linkage-to-care and treatment. Our study evaluated the accessibility and potential willingness of HIV self-testing among men who have sex with men (MSM) and transgender women in Peru. We surveyed four pharmacy chains in Peru to ascertain the commercial availability of the oral HIV self-test. The pharmacies surveyed confirmed that HIV self-test kits were available; however, those available were not intended for individual use, but for clinician use. We interviewed 147 MSM and 45 transgender women; nearly all (82%) reported willingness to perform the oral HIV self-test. However, only 55% of participants would definitely seek a confirmatory test in a clinic after an HIV-positive test result. Further, price may be a barrier, as HIV self-test kits were available for 18 USD, and MSM and transgender women were only willing to pay an average of 5 USD. HIV self-testing may facilitate increased access to HIV testing among some MSM/transgender women in Peru. However, price may prevent use, and poor uptake of confirmatory testing may limit linkage to HIV treatment and care.

High prevalence of extra-genital chlamydial or gonococcal infections among men who have sex with men and transgender women in Lima, Peru

Chlamydia trachomatis and Neisseria gonorrhoeae are among the most common sexually transmitted bacterial infections in the world. Data are limited, however, on the burden of extra-genital chlamydial and gonococcal infections among men who have sex with men and transgender women in Lima, Peru. Data were gathered from self-collected anal or pharyngeal swabs from participants in Lima, Peru, and analyzed via cross-sectional methods. Prevalence ratios for the association between extra-genital infection with socio-demographic and sexual behaviors were determined. Overall, 127 (32.8%) participants had anal or pharyngeal infections. On multivariate modeling, anal infection was positively associated with practicing both receptive and insertive anal sex, when compared to insertive alone (PR = 2.49; 95% CI = 1.32-4.71), and negatively associated with any antibiotic use in the prior three months (PR = 0.60; 95% CI = 0.39-0.91). Pharyngeal infection was negatively associated with age greater than 30 years compared to 18-30 years (PR = 0.54; 95% CI = 0.30-0.96), and positively associated with gender identity of transgender women (PR = 2.12; 95% CI = 1.20-3.73). This study demonstrates considerable burden of extra-genital chlamydial and gonococcal infections among men who have sex with men and transgender women in Lima, Peru.

Laboratory Evaluation of a Point-of-Care Downward-Flow Assay for Simultaneous Detection of Antibodies to Treponema pallidum and Human Immunodeficiency Virus

Combining the detection of syphilis and HIV antibodies into one point-of-care test integrates syphilis screening into already existing HIV screening programs, which may be particularly beneficial in settings such as antenatal care. Using the INSTI Multiplex downward-flow immunoassay, we tested 200 stored serum samples from high-risk patients enrolled in a longitudinal study on HIV infection and syphilis in Peruvian men who have sex with men and transgender women. This rapid assay detected HIV and Treponema pallidum serum antibodies with sensitivities of 100% (95% confidence interval [CI], 95.9% to 100%) and 87.4% (95% CI, 81.4% to 92.0%), respectively, and specificities of 95.5% (95% CI, 89.9% to 98.5%) and 97.0% (95% CI, 84.2% to 99.9%), respectively (n = 200). The sensitivity for syphilis antibody detection was higher in patients with a rapid plasma reagin titer of ≥1:8 (97.3%) than in those with a titer of ≤1:4 (90%) or a nonreactive titer (66.7%).

Impact of alcohol use on sexual behavior among men who have sex with men and transgender women in Lima, Peru

BACKGROUND

Alcohol use disorders (AUDs) may enhance the likelihood of risky sexual behaviors and the acquisition of sexually transmitted infections (STIs). Associations between AUDs with condomless anal intercourse (CAI) and STI/HIV prevalence were assessed among men who have sex with men (MSM) and transgender women (TW) in Lima, Peru.

METHODS

MSM and TW were eligible to participate based on a set of inclusion criteria which characterized them as high-risk. Participants completed a bio-behavioral survey. An AUDIT score ≥8 determined AUD presence. Recent STI diagnosis included rectal gonorrhea/chlamydia, syphilis, and/or new HIV infection within 6 months. Prevalence ratios (PR) were calculated using Poisson regression.

RESULTS

Among 312 MSM and 89 TW, 45% (181/401) had an AUD. Among those with an AUD, 164 (91%) were hazardous/harmful drinkers, and 17 (9%) had alcohol dependence. Higher CAI was reported by participants with an AUD vs. without, (82% vs. 72% albeit not significant). Reporting anal sex in two or more risky venues was associated with screening AUD positive vs. not (24% vs. 15%, p=0.001). There was no difference in recent STI/HIV prevalence by AUD status (32% overall). In multivariable analysis, screening AUD positive was not associated with CAI or recent STI/HIV infection.

CONCLUSIONS

In our sample AUDs were not associated with CAI or new HIV infection/recent STI. However higher prevalence of CAI, alcohol use at last sex, and anal sex in risky venues among those with AUDs suggests that interventions to reduce the harms of alcohol should be aimed toward specific contexts.

Laboratory Evaluation of a Dual-Path Platform Assay for Rapid Point-of-Care HIV and Syphilis Testing

We assessed the laboratory performance of the Chembio dual-path platform HIV-syphilis rapid immunodiagnostic test and electronic reader for detection of HIV and Treponema pallidum antibodies in 450 previously characterized serum specimens. For visual or electronic reader HIV antibody detection, the sensitivity was 100% and the specificity was 98.7%. For visual T. pallidum antibody detection, the test sensitivity was 94.7% and the specificity was 100.0%; with the electronic reader, the sensitivity was 94.7% and the specificity was 99.7%.

Clinical Outcomes of In Vitro Fertilization among Chinese Infertile Couples Treated for Syphilis Infection

To compare the clinical outcomes of infertile patients with and without syphilis after in vitro fertilization and embryo transfer (IVF-ET), in this case-control study, 320 infertile couples were enrolled and divided into syphilis (n = 160) and control groups (n = 160). The primary IVF outcomes were the clinical pregnancy rate and the birth of a healthy baby. All syphilis patients received the standard anti-syphilis treatment before undergoing IVF/ICSI. Our results showed that the endometrial thickness of the syphilis group was greater than that of the control group following hCG injection (16.9±5.4 vs. 13.0±4.7 mm, P<0.001). The numbers of normally fertilized eggs and normally cleaved fertilized eggs and the implantation rate were 6.8±4.8, 6.3±4.7 and 24.2%, respectively, for the syphilis group and 8.3±4.6, 8.1±4.6 and 34.4%, respectively, for the control group, and these values were significantly different between the groups. The clinical pregnancy rate was lower in the syphilis group compared with that in the control group (43.8% vs. 55.6%, P = 0.03). Lower offspring birth weight was observed in the infected male group compared with those in the infected female (2.7±0.4 vs. 3.0±0.4 kg, P = 0.01) and infected couple groups (2.7±0.4 vs. 3.1±0.5 kg, P = 0.007). Therefore, syphilis infection reduces the clinical pregnancy rate after IVF/ICSI.

Effect of individual behavior on epidemic spreading in activity-driven networks

In this work we study the effect of behavioral changes of individuals on the propagation of epidemic diseases. Specifically, we consider a susceptible-infected-susceptible model over a network of contacts that evolves in a time scale that is comparable to the individual disease dynamics. The phenomenon is modeled in the context of activity-driven networks, in which contacts occur on the basis of activity potentials. To offer insight into behavioral strategies targeting both susceptible and infected individuals, we consider two separate behaviors that may emerge in respiratory syndromes and sexually transmitted infections. The first is related to a reduction in the activity of infected individuals due to quarantine or illness. The second is instead associated with a selfish self-protective behavior of susceptible individuals, who tend to reduce contact with the rest of the population on the basis of a risk perception. Numerical and theoretical results suggest that behavioral changes could have a beneficial effect on the disease spreading, by increasing the epidemic threshold and decreasing the steady-state fraction of infected individuals.