Seroconversion in syphilis screening without positive confirmatory tests points at early infection

INTRODUCTION

The chemiluminescence immunoassay (CLIA) is a widely used screening test for syphilis. A CLIA seroconversion in the absence of a positive line immunoassay (LIA) or rapid plasma reagin (RPR) could indicate either an early incubating syphilis or a false positive result. We aimed to evaluate the diagnostic value of such seroconversions.

METHODS

We retrospectively analysed data of clients visiting the Centre for Sexual Health Amsterdam between July 2013 and August 2021 with a positive CLIA and a negative RPR and negative or indeterminate LIA (at time To), and a preceding visit (T-1) with a negative CLIA <6 months of To ('unconfirmed CLIA seroconversion'). If available, data of follow-up visits (T1) <2 months of To were also included. A syphilis diagnosis was confirmed if darkfield microscopy or PCR for Treponema pallidum was positive at T0 or T1, or if RPR and/or LIA were positive at T1.

RESULTS

We included data of 107 clients with unconfirmed CLIA seroconversion. The value of CLIA seroconversion could not be established in 13 (12.1%) clients. In the remaining 94 clients, the unconfirmed CLIA seroconversion was confirmed as early syphilis in 72 (76.6%) clients and probable syphilis in 6 (6.4%) clients. In 16 (17.0%) clients, the unconfirmed CLIA seroconversion was regarded as a false positive reaction of whom 4 (5.3%) clients had a seroreversion of the CLIA at T1.

CONCLUSION

The majority of unconfirmed CLIA seroconversions represented early syphilis infections. Therefore, additional T. pallidum PCR, a follow-up consultation or early treatment is recommended.

Can laboratory HIV and infectious syphilis data inform future pre-exposure prophylaxis use in women in Ontario, Canada?

OBJECTIVES

Infectious syphilis has been proposed as an indication for HIV pre-exposure prophylaxis (PrEP) in women. We explored how many women experienced HIV seroconversion after being diagnosed with syphilis in Ontario between 20 April 2010 and 31 December 2021.

METHODS

Through deterministic linkage of laboratory data at the Public Health Ontario laboratory, which conducts the vast majority of syphilis and HIV testing in Ontario, we quantified the number of females with positive syphilis diagnoses who subsequently exhibited HIV seroconversion between April 2010 and December 2021. New HIV cases were identified by diagnostic serology or HIV viral load test result of ≥20 copies/mL at least 60 days after the positive syphilis test. We report aggregate numbers of women with new laboratory evidence of HIV infection after their first positive syphilis test.

RESULTS

Among 7957 women with positive syphilis tests during the study period, 6554 (82.4%) had linkable HIV serology tests and 133 (1.7%) ever tested HIV positive. With further linkage to viral load data, the number of women who ever had laboratory evidence of HIV infection increased to 184 (2.3%). However, when restricting to women whose first positive HIV test or HIV viral load occurred after their first positive syphilis test, this number decreased to 34 (0.4%). The median (IQR) time between the positive syphilis test and the first laboratory evidence of HIV was 551 (IQR=226-1159) days.

CONCLUSION

Although it is clinically appropriate to recommend HIV PrEP to women with syphilis, Ontario surveillance data suggest that the population-level impact of this strategy on the HIV epidemic in Ontario would have been modest during this 11-year period. Future studies should explore additional ways of prioritising women for PrEP.

Painful proctitis associated with anorectal mpox, syphilis, HSV, LGV, gonorrhoea and Mycoplasma genitalium in a person living with virologically suppressed HIV and vaccinated against mpox

A gay man with well-controlled HIV and vaccinated against mpox presented with severe proctitis. Testing revealed anorectal mpox, herpes simplex virus, lymphogranuloma venereum, Neisseria gonorrhoeae and Mycoplasma genitalium Serology was indicative of infectious syphilis. This case highlights the need to consider a wide range of concurrent sexually transmitted infections in patients with proctitis, including those vaccinated against mpox.

Multicentric evaluation of a specific intrathecal anti-Treponema pallidum IgG index as a diagnostic biomarker of neurosyphilis: results from a retro-prospective case-control study

BACKGROUND AND OBJECTIVES

The diagnosis of neurosyphilis (NS) lacks a true 'gold standard', making the diagnosis challenging while consequences of a misdiagnosis are potentially severe. The aim of this study was to evaluate the diagnostic performance of measuring an antibody index (AI) for the intrathecal synthesis of specific anti-Treponema pallidum (T. pallidum) IgG for the diagnosis of NS.

METHODS

Specific anti-T. pallidum IgG were measured simultaneously in paired cerebrospinal fluid (CSF)-serum samples collected retrospectively and prospectively between 2007 and 2022, from patients suspected of NS, in Switzerland. An AI was calculated to account for blood-brain barrier integrity. Area under the receiver operating characteristic curve, sensitivity/specificity and positive/negative predictive values of AI test were estimated. Two NS definitions were used: NS1 included patients with NS suspicion presenting with neurological symptoms and/or acute neurosensory signs, and positive T. Pallidum Hemagglutinations Assay (TPHA)/T. pallidum particle agglutination assay (TPPA) serology and CSF-TPHA/TPPA ≥320, and either CSF-leucocytes >5 cells/mm3 and/or CSF-protein >0.45 g/L and/or a reactive CSF-venereal disease research laboratory (VDRL)/rapid plasma reagin (RPR) test. NS2 included patients with suspected NS presenting with acute ocular and/or otologic symptoms, and positive TPHA/TPPA serology, and a favourable response to NS treatment. Controls were patients diagnosed with any other central nervous system (CNS) pathologies and with positive TPHA/TPPA serology.

RESULTS

The study included 71 NS (43 NS1 and 28 NS2) and 110 controls. With a threshold of ≥1.7, sensitivity and specificity of the specific AI test were 90.7% (CI 77.7 to 97.4) and 100% (CI 96.7 to 100.0), respectively, for NS1 and 14.3% (CI 4 to 32.7) and 100% (CI 96.7 to 100.0) for NS2. In patients suspected of NS with a CNS involvement (NS1 group), NS could be confirmed by the positivity of this specific AI.

CONCLUSIONS

Measurement of an intrathecal synthesis index of specific anti-T. pallidum IgG in patients with CSF inflammatory signs appears to be a valuable diagnostic test. However, in otic or ocular syphilis, presenting few CSF abnormalities, AI is not sufficient alone to confirm NS diagnosis.

TRIAL REGISTRATION

Swiss Association of Research Ethics Committees number 2019-00232.

Sexual network characteristics and partnership types among men who have sex with men diagnosed with syphilis, gonorrhoea and/or chlamydia in Lima, Peru

OBJECTIVES

Sexual networks are known to structure sexually transmitted infection (STI) transmission among men who have sex with men (MSM). We sought to estimate the risks of STI diagnosis for various partnership types within these networks.

METHODS

Our cross-sectional survey analysed data from 1376 MSM screened for a partner management intervention in Lima, Peru. Participants were tested for HIV, syphilis, gonorrhoea (NG) and chlamydia (CT) and completed surveys on their demographics, sexual identity/role, HIV status, partnership types and sexual network from the prior 90 days. χ2 and Wilcoxon rank-sum tests compared participants without an STI to those diagnosed with (1) syphilis, (2) NG and/or CT (NG/CT) and (3) syphilis and NG/CT coinfection (coinfection).

RESULTS

40.8% (n=561/1376) of participants were diagnosed with an STI (syphilis: 14.9%, NG/CT: 16.4%, coinfection: 9.5%). 47.9% of all participants were living with HIV and 8.9% were newly diagnosed. A greater proportion of participants with syphilis and coinfection were living with HIV (73.5%, p<0.001; 71.0%, p<0.001) compared with those with NG/CT (47.8%) or no STI (37.8%). Participants with syphilis more often reported sex-on-premises venues (SOPVs) as the location of their last sexual encounter (51.7%, p=0.038) while those with NG/CT tended to meet their last sexual partner online (72.8%, p=0.031). Respondents with coinfection were the only STI group more likely to report transactional sex than participants without an STI (31.3%, p=0.039).

CONCLUSIONS

Sexual networks and partnership types of Peruvian MSM are associated with differential risks for STIs. Participants diagnosed with syphilis tended to meet single-encounter casual partners at SOPV, while MSM with NG/CT were younger and often contacted casual partners online. Coinfection had higher frequency of transactional sex. These findings suggest the potential importance of public health interventions through combined syphilis/HIV screening at SOPV, syphilis screening at routine clinic appointments for MSM living with HIV and directed advertisements and/or access to NG/CT testing through online platforms.

Recent changes in the reporting of STIs in Japan during the COVID-19 pandemic

OBJECTIVES

The COVID-19 pandemic has had variable effects on the rates of STIs reported across the globe. This study sought to assess how the number of STI reports changed during the pandemic in Japan.

METHODS

We used national infectious disease surveillance data from the National Institute of Infectious Diseases (Tokyo, Japan) for the period between January 2013 and December 2021. We compared reported rates of chlamydia, gonorrhoea, condyloma acuminata and genital herpes, as well as total notifications for HIV/AIDS and syphilis during the pandemic versus previous years in Japan. We used a quasi-Poisson regression to determine whether any given week or month between January 2018 and December 2021 had a significant excess or deficit of STIs. Notification values above or below the 95% upper and lower prediction thresholds were considered as statistically significant. The start of the pandemic was defined as January 2020.

RESULTS

Chlamydia generally remained within predicted range during the pandemic period. Reporting of gonorrhoea was significantly higher than expected throughout early-to-mid 2021 but otherwise generally remained within predicted range prior to 2021. Condyloma, herpes and HIV/AIDS reporting were transiently significantly lower than expected throughout the pandemic period, but no significant periods of higher-than-expected reporting were detected. Syphilis showed widespread evidence of significantly lower-than-predicted reporting throughout 2020 but eventually reversed, showing significantly higher-than-predicted reporting in mid-to-late 2021.

CONCLUSIONS

The COVID-19 pandemic was associated with variable changes in the reporting of STIs in Japan. Higher-than-predicted reporting was more likely to be observed in the later phases of the pandemic. These changes may have been attributable to pandemic-related changes in sexual behaviour and decreased STI clinic attendance and testing, but further research on the long-term impact of the pandemic on STIs is necessary.

Improved rapid diagnostic tests to detect syphilis and yaws: a systematic review and meta-analysis

BACKGROUND

Current rapid tests for syphilis and yaws can detect treponemal and non-treponemal antibodies. We aimed to critically appraise the literature for rapid diagnostic tests (RDTs) which can better distinguish an active infection of syphilis or yaws.

METHODS

We conducted a systematic review and meta-analysis, searching five databases between January 2010 and October 2021 (with an update in July 2022). A generalised linear mixed model was used to conduct a bivariate meta-analysis for the pooled sensitivity and specificity. Heterogeneity was assessed using the I² statistic. We used the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) to assess the risk of bias and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) to evaluate the certainty of evidence.

RESULTS

We included 17 studies for meta-analyses. For syphilis, the pooled sensitivity and specificity of the treponemal component were 0.93 (95% CI: 0.86 to 0.97) and 0.98 (95% CI: 0.96 to 0.99), respectively. For the non-treponemal component, the pooled sensitivity and specificity were 0.90 (95% CI: 0.82 to 0.95) and 0.97 (95% CI: 0.92 to 0.99), respectively. For yaws, the pooled sensitivity and specificity of the treponemal component were 0.86 (95% CI: 0.66 to 0.95) and 0.97 (95% CI: 0.94 to 0.99), respectively. For the non-treponemal component, the pooled sensitivity and specificity were 0.80 (95% CI: 0.55 to 0.93) and 0.96 (95% CI: 0.92 to 0.98), respectively.

CONCLUSIONS

RDTs that can differentiate between active and previously treated infections could optimise management by providing same-day treatment and reducing unnecessary treatment.

PROSPERO REGISTRATION NUMBER

CRD42021279587.

Anal and oral detection of Treponema pallidum in men who have sex with men with early syphilis infection

OBJECTIVES

We aimed to characterise patterns of anal and oral detection of Treponema pallidum among men who have sex with men (MSM) with early syphilis.

METHODS

200 MSM with serologically confirmed primary, secondary and early latent syphilis were tested with T. pallidum polA PCR using an anal canal swab, oral rinse, plus swabs from any anal and oral lesions in a prospective, cross-sectional study. Anal and oral T. pallidum cycle threshold values were compared between subsets of men and according to rapid plasma reagin (RPR) titre.

RESULTS

Of 200 men with early syphilis, 45 and 48 had anal and oral T. pallidum detected, respectively. Cycle threshold values were lower with anal compared with oral T. pallidum whether lesions were present or not. Among 27 and 42 men with anal and oral T. pallidum detected, respectively, and no anal or oral primary lesion, frequency of detection increased with increasing RPR titre, with 95% (25/27) and 98% (41/42) of shedding from respective sites occurring with RPR titres ≥1:16. 6.5% (13/200) of men with syphilis had concurrent detection of T. pallidum from both anal and oral sites: 9/13 with secondary syphilis, 7/9 of whom had anal lesions with a median duration of 30 days (range 7-180 days).

CONCLUSIONS

These data suggest T. pallidum load at the anus is higher than at the oral cavity and that a subset of men with secondary syphilis and prolonged anal lesions may be relatively infectious. Earlier detection and treatment of syphilis, when RPR titres are lower than 1:16, could potentially reduce infectiousness from anal and oral sites.

Clinical and laboratory aspects of condylomata lata lesions of syphilis

OBJECTIVES

Condylomata lata are a less common but distinctive syphilitic lesion. Variable theories as to their nature and origin exist. The aim of this study was to determine the clinical and laboratory characteristics of condylomata lata by determining (1): the most closely aligned stage of syphilis, based on the rapid plasma reagin (RPR) titre; (2) symptom duration and (3) Treponema pallidum PCR cycle threshold (C_T) values, as an indicator of organism load.

METHODS

This was a retrospective study of patients with T. pallidum PCR-positive condylomata lata lesions, attending a clinic in Melbourne, Australia, between 2011 and 2021. Syphilis serology was undertaken and RPR titres compared between condylomata lata, primary and secondary syphilis cases.

RESULTS

51 cases with T. pallidum PCR-positive condylomata lata were included. 41 cases were in men, 40 of whom were men who have sex with men (MSM), and 10 in women. Twelve of 51 (24%) cases were in HIV-positive MSM. Thirty-three of 51 (65%) had other mucocutaneous signs of secondary syphilis; 18 (35%) had no other signs of secondary syphilis. The median RPR titre among the 51 condylomata lata cases was 1:128, compared with the median RPR titre of primary syphilis (1:4) and of secondary syphilis (1:128). The median duration of lesions was 24 (IQR 10-60) days, with no significant difference between those with and without other signs of secondary syphilis (p=0.75). Median C_T values for condylomata lata (C_T=31) and primary syphilis (C_T=31) were significantly lower than for other secondary syphilis lesion types (C_T=33), indicating higher T. pallidum loads for condylomata lata and primary lesions compared with other secondary syphilis lesion types.

DISCUSSION

These findings support condylomata lata as lesions that occur during the secondary stage of syphilis and which are likely to be highly infectious.

Can we screen less frequently for STI among PrEP users? Assessing the effect of biannual STI screening on timing of diagnosis and transmission risk in the AMPrEP Study

BACKGROUND

In many countries, HIV pre-exposure prophylaxis (PrEP) users are screened quarterly for STIs. We assessed the consequences of less frequent STI testing. We also assessed determinants of asymptomatic STI and potential for onward transmission.

METHODS

Using data from the AMPrEP study, we assessed the proportion of syphilis, and genital, anal, and pharyngeal chlamydia and gonorrhoea diagnoses which would have been delayed with biannual versus quarterly screening. We assessed the potential for onward transmission by examining reported condomless anal sex (CAS) in periods after to-be-omitted visits when screening biannually. We assessed determinants of incident asymptomatic STIs using Poisson regression and calculated individual risk scores on the basis of the coefficients from this model.

RESULTS

We included 366 participants. Median follow-up was 47 months (IQR 43-50). 1,183STIs were diagnosed, of which 932(79%) asymptomatic. With biannual screening, 483 asymptomatic STIs (52%) diagnoses would have been delayed at 364 study visits. Of these visits, 129 (35%), 240 (66%) and 265 (73%) were followed by periods of CAS with steady, known casual or unknown casual partners, respectively. Older participants had a lower risk of asymptomatic STI (incidence rate ratio (IRR) 0.86/10-year increase, 95% CI 0.80 to 0.92), while CAS with known (IRR 1.36, 95% CI 1.10 to 1.68) and unknown (IRR 1.86, 95% CI 1.48 to 2.34) casual partners and chemsex (IRR 1.51, 95% CI 1.28 to 1.78) increased the risk. The individual risk scores had limited predictive value (sensitivity=0.70 (95% CI 0.66 to 0.74), specificity=0.50 (95% CI 0.48 to 0.51)).

CONCLUSION

Reducing the STI screening frequency to biannually among PrEP users will likely result in delayed diagnoses, potentially driving onward transmission. Although determinants for asymptomatic STIs were identified, predictive power was low.

A double-edged sword: does highly active antiretroviral therapy contribute to syphilis incidence by impairing immunity to Treponema pallidum?

BACKGROUND AND HYPOTHESIS

Recently, the world has experienced a rapidly escalating outbreak of infectious syphilis primarily affecting men who have sex with men (MSM); many are taking highly active antiretroviral therapy (HAART) for HIV-1 infection. The prevailing hypothesis is that HAART availability and effectiveness have led to the perception among both individuals who are HIV-1 infected and those who are uninfected that HIV-1 transmission has become much less likely, and the effects of HIV-1 infection less deadly. This is expected to result in increased sexual risk-taking, especially unprotected anal intercourse, leading to more non-HIV-1 STDs, including gonorrhoea, chlamydia and syphilis. However, syphilis incidence has increased more rapidly than other STDs. We hypothesise that HAART downregulates the innate and acquired immune responses to Treponema pallidum and that this biological explanation plays an important role in the syphilis epidemic.

METHODS

We performed a literature search and developed a mathematical model of HIV-1 and T. pallidum confection in a population with two risk groups with assortative mixing to explore the consequence on syphilis prevalence of HAART-induced changes in behaviour versus HAART-induced biological effects.

CONCLUSIONS AND IMPLICATIONS

Since rising syphilis incidence appears to have outpaced gonorrhoea and chlamydia, predominantly affecting HIV-1 positive MSM, behavioural factors alone may be insufficient to explain the unique, sharp increase in syphilis incidence. HAART agents have the potential to alter the innate and acquired immune responses in ways that may enhance susceptibility to T. pallidum. This raises the possibility that therapeutic and preventative HAART may inadvertently increase the incidence of syphilis, a situation that would have significant and global public health implications. We propose that additional studies investigating the interplay between HAART and enhanced T. pallidum susceptibility are needed. If our hypothesis is correct, HAART should be combined with enhanced patient management including frequent monitoring for pathogens such as T. pallidum.

Can enhanced screening of men with a history of prior syphilis infection stem the epidemic in men who have sex with men? A mathematical modelling study

OBJECTIVES

The aim of this study is to determine the transmission impact of using prior syphilis infection to guide a focused syphilis screening intervention among men who have sex with men (MSM).

METHODS

We parameterised a deterministic model of syphilis transmission in MSM to reflect the 2011-2015 syphilis outbreak in Winnipeg, Canada. Enhanced screening of 75% of men with prior syphilis every 3 months (A) was compared with distributing equivalent number tests to all MSM (B) or those with the highest partner number (C). We compared early syphilis incidence, diagnoses and prevalence after 10 years, relative to a base case of 30% of MSM screened annually.

RESULTS

Strategy A was expected to avert 52% of incident infections, 44% of diagnosed cases and reduce early syphilis prevalence by 89%. Strategy B had the least impact. Strategy C was most effective, averting 59% of incident cases. When screening frequency was semiannual or annual, strategy A was the most effective.

CONCLUSIONS

Enhanced screening of MSM with prior syphilis may efficiently reduce transmission, especially when identification of high-risk men via self-reported partner numbers or high-frequency screening is difficult to achieve.

A comparative analysis of costs of single and dual rapid HIV and syphilis diagnostics: results from a randomised controlled trial in Colombia

Background

HIV and congenital syphilis are major public health burdens contributing to substantial perinatal morbidity and mortality globally. Although studies have reported on the costs and cost-effectiveness of rapid diagnostic tests (RDTs) for syphilis screening within antenatal care in a number of resource-constrained settings, empirical evidence on country-specific cost and estimates of single RDTs compared with dual RDTs for HIV and syphilis are limited.

Methods

A cluster randomised controlled study design was used to compare the incremental costs of two testing algorithms: (1) single RDTs for HIV and syphilis and (2) dual RDTs for HIV and syphilis, in 12 health facilities in Bogota and Cali, Colombia. The costs of single HIV and syphilis RDTs and dual HIV and syphilis RDTs were collected from each of the health facilities. The economic costs per woman tested for HIV and syphilis and costs per woman treated for syphilis defined as the total costs required to test and treat one woman for syphilis were estimated.

Results

A total of 2214 women were tested in the study facilities. Cost per pregnant woman tested and cost per woman treated for syphilis were US$10.26 and US$607.99, respectively in the single RDT arm. For the dual RDTs, the cost per pregnant woman tested for HIV and syphilis and cost per woman treated for syphilis were US$15.89 and US$1859.26, respectively. Overall costs per woman tested for HIV and syphilis and cost per woman treated for syphilis were lower in Cali compared with Bogota across both intervention arms. Staff costs accounted for the largest proportion of costs while treatment costs comprised <1% of the preventive programme.

Conclusions

Findings show lower average costs for single RDTs compared with dual RDTs with costs sensitive to personnel costs and the scale of output at the health facilities.

Trial registration number

NCT02454816; results.

Patterns of prevalent HPV and STI co-infections and associated factors among HIV-negative young Western Cape, South African women: the EVRI trial

OBJECTIVE

To estimate the prevalence and describe the patterns of concurrent human papillomavirus (HPV) and STIs and associated factors among HIV-negative young Western Cape, South African women participating in the Efficacy of HPV Vaccine to Reduce HIV Infection (EVRI) trial.

METHODS

HIV-negative women aged 16-24 years old were enrolled in the EVRI trial (NCT01489527) and randomised to receive the licensed four-valent HPV vaccine or placebo. At study entry, participants were clinically evaluated for five STIs: herpes simplex virus type 2 (HSV-2), chlamydia, gonorrhoea, syphilis and disease-causing HPV genotypes (6/11/16/18/31/33/35/39/45/51/52/56/58/59/68). Demographic and sexual history characteristics were compared among women with STI co-infections, single infection and no infection using Pearson χ² and Mann-Whitney tests. ORs were calculated to evaluate factors associated with STI co-infection prevalence.

RESULTS

Among 388 young women, STI co-infection prevalence was high: 47% had ≥2 concurrent STIs, 36% had a single STI and 17% had none of the five evaluated STIs. HPV/HSV-2 (26%) was the most prevalent co-infection detected followed by HPV/HSV-2/Chlamydia trachomatis (CT) (17%) and HPV/CT (15%). Co-infection prevalence was independently associated with alcohol use (adjusted OR=2.01, 95% CI 1.00 to 4.06) and having a sexual partner with an STI (adjusted OR=6.96, 95% CI 1.53 to 30.08).

CONCLUSIONS

Among high-risk young women from underserved communities such as in Southern Africa, a multicomponent prevention strategy that integrates medical and behavioural interventions targeting both men and women is essential to prevent acquisition of concurrent STI infections and consequent disease.

TRIAL REGISTRATION NUMBER

NCT01489527; Post-results.

Estimating prevalence trends in adult gonorrhoea and syphilis in low- and middle-income countries with the Spectrum-STI model: results for Zimbabwe and Morocco from 1995 to 2016

Objective

To develop a tool for estimating national trends in adult prevalence of sexually transmitted infections by low- and middle-income countries, using standardised, routinely collected programme indicator data.

Methods

The Spectrum-STI model fits time trends in the prevalence of active syphilis through logistic regression on prevalence data from antenatal clinic-based surveys, routine antenatal screening and general population surveys where available, weighting data by their national coverage and representativeness. Gonorrhoea prevalence was fitted as a moving average on population surveys (from the country, neighbouring countries and historic regional estimates), with trends informed additionally by urethral discharge case reports, where these were considered to have reasonably stable completeness. Prevalence data were adjusted for diagnostic test performance, high-risk populations not sampled, urban/rural and male/female prevalence ratios, using WHO's assumptions from latest global and regional-level estimations. Uncertainty intervals were obtained by bootstrap resampling.

Results

Estimated syphilis prevalence (in men and women) declined from 1.9% (95% CI 1.1% to 3.4%) in 2000 to 1.5% (1.3% to 1.8%) in 2016 in Zimbabwe, and from 1.5% (0.76% to 1.9%) to 0.55% (0.30% to 0.93%) in Morocco. At these time points, gonorrhoea estimates for women aged 15–49 years were 2.5% (95% CI 1.1% to 4.6%) and 3.8% (1.8% to 6.7%) in Zimbabwe; and 0.6% (0.3% to 1.1%) and 0.36% (0.1% to 1.0%) in Morocco, with male gonorrhoea prevalences 14% lower than female prevalence.

Conclusions

This epidemiological framework facilitates data review, validation and strategic analysis, prioritisation of data collection needs and surveillance strengthening by national experts. We estimated ongoing syphilis declines in both Zimbabwe and Morocco. For gonorrhoea, time trends were less certain, lacking recent population-based surveys.

Screening for asymptomatic neurosyphilis in HIV patients after treatment of early syphilis: an observational study

OBJECTIVE

To determine the prevalence of asymptomatic neurosyphilis (ANS) in HIV-positive individuals after treatment of early syphilis with single-dose benzathine penicillin G (BPG) or oral antibiotic alternatives.

METHODS

Patients at high risk of neurosyphilis (defined by serum rapid plasma reagin (RPR) titre ≥1:32 and/or peripheral blood CD4 lymphocyte count ≤350/μL) underwent lumbar puncture (LP) at a median time of 8.2 months post treatment. ANS was diagnosed by a reactive cerebrospinal fluid (CSF) RPR test or CSF white blood cells (WBC) >20/μL plus a reactive CSF Treponema pallidum particle agglutination (TPPA) ≥1:640.

RESULTS

Of 133 eligible patients, all were men who have sex with men. Of these, 64 consented to LP. Full CSF results were available for 59 patients. Inclusion criteria were serum RPR (21/59), CD4 count (22/59) and combined RPR and CD4 (16/59). The LP patients were white British (82%), median age 40. Syphilis stages were primary (17%) secondary (43%) and early latent (41%). Syphilis was treated with BPG (47/59), doxycycline 100 mg two times per day for 14 days (10/59) and for 21 days (1/59). Azithromycin 500 mg one time per day for 10 days was given to 1/59. At the time of LP, 100% of patients had achieved serological cure, and 66% were taking antiretroviral treatment. Only 1/59 was diagnosed with ANS. The CSF showed: RPR non-reactive (59/59); TPPA non-reactive in 54/59; WBC ≤5/μL in 51/59.

CONCLUSIONS

Although the number of patients in our study is modest, single-dose BPG appears to be highly effective even in patients at high risk of neurosyphilis.

Outbreaks of syphilis among men who have sex with men attending STI clinics between 2007 and 2015 in the Netherlands: a space-time clustering study

OBJECTIVES

Infectious syphilis (syphilis) is diagnosed predominantly among men who have sex with men (MSM) in the Netherlands and is a strong indicator for sexual risk behaviour. Therefore, an increase in syphilis can be an early indicator of resurgence of other STIs, including HIV. National and worldwide outbreaks of syphilis, as well as potential changes in sexual networks were reason to explore syphilis trends and clusters in more depth.

METHODS

National STI/HIV surveillance data were used, containing epidemiological, behavioural and clinical data from STI clinics. We examined syphilis positivity rates stratified by HIV status and year. Additionally, we performed space-time cluster analysis on municipality level between 2007 and 2015, using SaTScan to evaluate whether or not there was a higher than expected syphilis incidence in a certain area and time period, using the maximum likelihood ratio test statistic.

RESULTS

Among HIV-positive MSM, the syphilis positivity rate decreased between 2007 (12.3%) and 2011 (4.5%), followed by an increasing trend (2015: 8.0%). Among HIV-negative MSM, the positivity rate decreased between 2007 (2.8%) and 2011 also (1.4%) and started to increase from 2013 onwards (2015: 1.8%). In addition, we identified three geospatial clusters. The first cluster consisted of MSM sex workers in the South of the Netherlands (July 2009-September 2010, n=10, p<0.001). The second cluster were mostly HIV-positive MSM (58.5%) (Amsterdam; July 2011-December 2015; n=1123, p<0.001), although the proportion of HIV-negative MSM increased over time. The third cluster was large in space (predominantly the city of Rotterdam; April-September 2015, n=72, p=0.014) and were mostly HIV-negative MSM (62.5%).

CONCLUSIONS

Using SaTScan analysis, we observed several not yet recognised outbreaks and a rapid resurgence of syphilis among known HIV-positive MSM first, but more recently, also among HIV-negative MSM. The three identified clusters revealed locations, periods and specific characteristics of the involved MSM that could be used when developing targeted interventions.

Engagement in the HIV care cascade and barriers to antiretroviral therapy uptake among female sex workers in Port Elizabeth, South Africa: findings from a respondent-driven sampling study

BACKGROUND

Female sex workers (FSWs) are disproportionately affected by HIV, even in the context of broadly generalised HIV epidemics such as South Africa. This has been observed in spite of the individual and population-level benefits of HIV treatment. We characterise the HIV care cascade among FSWs and relationships with antiretroviral therapy (ART) use.

METHODS

FSWs ≥18 years were recruited through respondent-driven sampling into a cross-sectional study in Port Elizabeth, South Africa. Participants completed questionnaires and received HIV and syphilis testing; CD4 counts were assessed among women living with HIV. Engagement in the HIV care cascade is described, and correlates of self-reported ART use among treatment-eligible previously diagnosed FSWs were estimated using robust Poisson regression.

RESULTS

Between October 2014 and April 2015, 410 FSWs participated in study activities. Overall, 261/410 were living with HIV (respondent-driven sampling-weighted prevalence 61.5% (95% bootstrapped CI 54.1% to 68.0%)). Prior diagnosis of HIV was relatively high (214/261, 82%); however, ART coverage among FSWs living with HIV was 39% (102/261). In multivariate analyses, FSWs were less likely to be on ART if they had not disclosed their HIV status to non-paying partners (adjusted prevalence ratio (aPR) 0.43, 95% CI 0.22 to 0.86, where the reference is FSWs without non-paying partners), and also if they engaged in mobile healthcare services (aPR 0.71, 95% CI 0.57 to 0.89).

CONCLUSIONS

HIV testing and awareness of HIV status were high, but substantial losses in the cascade occur at treatment initiation. Given that FSWs engaged in mobile HIV testing and peer education programmes have unmet HIV treatment needs, models of decentralised treatment provision such as mobile-based ART care should be evaluated.

Very high incidence of syphilis in HIV-infected men who have sex with men in Buenos Aires city: a retrospective cohort study

BACKGROUND

The incidence of sexually transmitted infections (STIs), particularly syphilis, is high and continues to rise among some populations, especially among men who have sex with men (MSM). Furthermore, a higher incidence of STIs has been reported in HIV-positive than in HIV-negative MSM.

OBJECTIVE

To determine the incidence of syphilis in a cohort of men with HIV in Buenos Aires city.

METHODS

Retrospective cohort study. We examined the records and visits made by men with HIV aged >18 years in our institution during a 1-year period. Venereal Disease Reference Laboratory (VDRL) results for all the men in our cohort during the study period were analysed. We considered a case of syphilis as incident if a person had a VDRL result of ≥16 DILS, provided that this was increased at least fourfold compared with a previous determination. All VDRL results ≤8 were investigated, and analysed together with the medical records, to determine if they were new cases.

RESULTS

We analysed the VDRL results and the clinical records of 1150 men followed up in our centre during the study period. Mean age was 40.9 years. According to the definition used, we registered 171 new cases of syphilis-that is, an incidence of 14.9/100 patients/year (95% CI 12.9 to 17.0). No significant differences in incidence according to age group were found, but there was a trend towards a lower incidence in older men. Ten men had two new episodes during the study.

CONCLUSIONS

The incidence of syphilis in this cohort of men with HIV (predominantly MSM) was very high. In addition to maintaining high surveillance for early diagnosis and treatment, it is necessary to implement newer and more effective measures to prevent syphilis and other STIs in this population.

High HIV incidence in men who have sex with men following an early syphilis diagnosis: is there room for pre-exposure prophylaxis as a prevention strategy?

OBJECTIVES

HIV pre-exposure prophylaxis (PrEP) is becoming a pivotal strategy for HIV prevention. Understanding the impact of risk factors for HIV transmission to identify those at highest risk would favour the implementation of PrEP, currently limited by costs. In this service evaluation, we estimated the incidence of bacterial STIs in men who have sex with men (MSM) diagnosed with early syphilis attending a London sexual health clinic according to their HIV status. In addition, we estimated the incidence of HIV infection in HIV-negative MSM, following a diagnosis of early syphilis.

METHODS

We undertook a retrospective case note review of all MSM patients diagnosed with early syphilis between January and June 2014. A number of sexual health screens and diagnoses of chlamydia, gonorrhoea and HIV were prospectively analysed following the syphilis diagnosis.

RESULTS

206 MSM were diagnosed with early syphilis. 110 (53%) were HIV-negative at baseline, 96 (47%) were HIV-positive. Only age (37 vs 32 years, p=0.0005) was significantly different according to HIV status of MSM at baseline. In HIV-negative versus HIV-positive MSM, incidence of rectal chlamydia infection at follow-up was 27 cases vs 50/100 person-years of follow-up (PYFU) (p=0.0039), 33 vs 66/100 PYFU (p=0.0044) for rectal gonorrhoea and 10 vs 26/100 PYFU (p=0.0044) for syphilis reinfection, respectively. Total follow-up for 110 HIV-negative MSM was 144 person-years. HIV incidence was 8.3/100 PYFU (CI 4.2 to 14).

CONCLUSIONS

A diagnosis of early syphilis carries a high risk of consequent HIV seroconversion and should warrant prioritised access to prevention measures such as PrEP and regular STI screening to prevent HIV transmission.

Robust pro-inflammatory immune response is associated with serological cure in patients with syphilis: an observational study

OBJECTIVES

Approximately 15% of adequately treated patients with early syphilis remain serofast. Pathogenesis and clinical significance of this phenomenon is unclear. The objective of this study was to determine whether there is any association between host immune response and treatment outcome (serofast state or proper serological response).

METHODS

Forty-four patients with secondary syphilis were enrolled to this study. Levels of pro-inflammatory cytokines such as interferon-γ, tumour necrosis factor-α and interleukin-6 were measured before treatment and 8 hours after injection of antibiotic.

RESULTS

After 1 year, based on the serological response patients were stratified into two groups: (1) proper serological response (n=31) and (2) serofast state (n=9). The serological cure rate was 77.5% at 12 months after treatment. Patients with proper serological response had significantly higher levels of analysed cytokines (at baseline and 8 hours after treatment) compared with the serofast state group (p<0.05).

CONCLUSIONS

We showed that robust host pro-inflammatory immune response to infection may be the predictive factor of serological cure. The treatment outcome may be also associated with the magnitude of immune reaction occurring during the treatment.

A case-control study evaluating the role of internet meet-up sites and mobile telephone applications in influencing a syphilis outbreak: Multnomah County, Oregon, USA 2014

OBJECTIVES

Early syphilis in Multnomah County, Oregon, USA, increased 16-fold during 2007-2013. Cases predominantly occurred among men who have sex with men (MSM); 55% were HIV coinfected. We conducted a case-control study to evaluate the association between meeting sex partners online and early syphilis.

METHODS

Cases subjects (cases) were Multnomah County resident, English speaking, MSM, aged ≥18 years with laboratory-confirmed early syphilis reported 1 January to 31 December 2013. We recruited two MSM controls subjects (controls) per case, frequency matched by HIV status and age. Participants completed self-administered questionnaires. We performed multivariable logistic regression.

RESULTS

Seventy per cent (40/57) of cases and 42% (50/119) of controls met partners online (p<0.001). Cases more frequently met partners online (adjusted OR (aOR)=3.0; 95% CI 1.2 to 6.7), controlling for presumptive confounders. Cases reported more partners than controls (medians 5, 2; p<0.001). When including number of partners, aOR decreased to 1.4 (95% CI 0.5 to 3.9).

CONCLUSIONS

Early syphilis was associated with meeting partners online. We believe this association may be related to number of sex partners acting as an intermediate variable between use of online resources to meet sex partners and early syphilis. Online meet-up sites might represent areas for public health interventions targeting at-risk individuals.

Field evaluation of Standard Diagnostics' Bioline HIV/Syphilis Duo test among female sex workers in Johannesburg, South Africa

BACKGROUND

Point-of-care tests provide immediate results with the opportunity for same-day interventions with improved public health outcomes. A dual HIV/syphilis test enables early treatment of both diseases.

METHODS

We conducted a field evaluation of the Standard Diagnostics' SD Bioline HIV/Syphilis Duo test (SD Bioline) among female sex workers. SD Bioline was conducted on finger-prick blood according to manufacturer's instructions and compared with (i) Genscreen HIV1/2 (third generation) and Vironostika Ag/Ab (fourth generation) assays for HIV, and (ii) Treponema pallidum particle agglutination (TPPA) and rapid plasma reagin (RPR) assays for syphilis. A negative TPPA test was considered negative, a TPPA-confirmed RPR titre ≤1:4 as past infection and a TPPA-confirmed RPR titre ≥1:8 as active syphilis. Sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS

Of 263 women recruited, 14 (5.3%) declined an HIV test. Among the remaining 249 women, 187 (75.1%) were HIV positive, 51 (20.5%) had syphilis antibodies with seven (2.8%) active infections. For HIV, the sensitivity and specificity were 98.9% (95% CI 95.8% to 99.8%) and 100% (95% CI 92.7% to 100%). For syphilis, the sensitivity and specificity were 66.7% (95% CI 52.0% to 78.9%) and 98.0% (95% CI 94.5% to 99.3%). Sera with high TPPA titres were more likely to test positive.

CONCLUSIONS

In field conditions, while the SD Bioline test has high sensitivity and specificity for HIV and high specificity for syphilis, the test has lower sensitivity for syphilis than reported from laboratory evaluations. As the dual test detects only two thirds of syphilis cases, it should only be used in areas with weak screening programmes.

Identifying and interpreting spatiotemporal variation in diagnoses of infectious syphilis among men, England: 2009 to 2013

OBJECTIVES

Spatial clusters and variations in the trajectory of local epidemics were explored in relation to sexual orientation, demographic factors, stage of syphilis infection and HIV serostatus.

METHODS

Kulldorff's scan statistics (SaTScan) was used to distinguish endemic and temporary clusters using a two-stage analysis.

RESULTS

Endemic areas were found in London, Manchester, Brighton and Blackpool. Up to 40% of diagnoses were found within an 11 km radius of central London. Of men diagnosed with syphilis in London, 80% were men who have sex with men (MSM). Annual incidence in London increased from 24 cases (95% CI 23 to 26) per 100 000 male population in 2009 to 36 cases (95% CI 34 to38) in 2013. In comparison with clusters, endemic areas were characterised by a significantly higher (p<0.05) proportion of MSM (83% compared with 73%), increased HIV positivity (41% vs 15%), age 35 to 44 years (34% vs 23%), a lower proportion of patients born in the UK (50% vs 79%) and a lower proportion of primary stage infection (40% vs 47%). Space-time clusters outside endemic areas occurred in urban and rural areas and diagnoses fluctuated below 10 per month. Exponential increases in diagnoses resembling point source outbreaks were seen at two locations.

CONCLUSION

Control of syphilis in endemic areas has proved elusive and clusters present unique intervention opportunities. Investigating the diversity of local epidemics provides information that can be used to predict outbreak structure, plan and evaluate sexual health services and guide public health investigation, hypothesis generation and research.

Outbreak of syphilis in men who have sex with men living in rural North Wales (UK) associated with the use of social media

OBJECTIVES

To describe an outbreak of infectious syphilis in rural North Wales and the control measures implemented.

METHODS

Following reports of an increase of syphilis in North Wales, a multidisciplinary Outbreak Control Team (OCT) was established. A multilevel prevention and control response was initiated, including: active case surveillance, partner notification and treatment, sexual network analysis, awareness raising with professionals and affected communities, point-of-care syphilis testing at a sauna and a health promotion campaign targeting users of men who have sex with men (MSM) social network mobile phone applications (apps).

RESULTS

Four cases of infectious syphilis were diagnosed in clinics in North Wales per 100 000 population in 2013 compared with a mean of one case per 100 000 in the preceding decade. Diagnosed cases peaked in January 2014, declining in the first half of 2014. Initial cases were clustered in the westerly rural counties of North Wales and were predominantly white men, self-reporting as MSM (median age: 34 years, range: 17-61). Point-of-care testing at a sauna did not identity further new infections, suggesting that the cluster was relatively focused and had probably been detected early. The use of apps to find sexual partners was a feature of the network affected. A health promotion campaign, initiated by the OCT, targeting men using MSM apps reached 92% of the 755 men messaged.

CONCLUSIONS

The outbreak was successfully controlled. However, it is difficult to determine which of the interventions implemented were most effective. Future outbreaks should be used as an opportunity to evaluate interventions using apps.

Prognosis of ocular syphilis in patients infected with HIV in the antiretroviral therapy era

OBJECTIVE

To describe the clinical course and prognosis of ocular syphilis in patients infected with HIV-1 in the antiretroviral therapy (ART) era.

METHODS

We conducted a single-centre retrospective chart review of ocular syphilis in patients infected with HIV-1 diagnosed between August 1997 and July 2015. The prognosis of best-corrected visual acuity (BCVA) was analysed.

RESULTS

The study subjects were 30 eyes of 20 men who had sex with men (MSM) (median age, 41). Loss of vision and posterior uveitis were the most common ocular clinical features (43%) and location of inflammation at presentation (50%), respectively. The median baseline BCVA was 0.4 (IQR 0.2-1.2), including three eyes with hand motion. BCVA≤0.4 at diagnosis was significantly associated with posterior uveitis or panuveitis (p=0.044). Seventy-five per cent were treated with intravenous benzylpenicillin and 53% were diagnosed with neurosyphilis. After treatment (median follow-up: 21 months), BCVA improved in 89% of the eyes, including all eyes with hand motion, to a median BCVA of 1.2 (IQR 0.8-1.2). Kaplan-Meier analysis showed that >28 days of ocular symptoms before diagnosis was the only factor associated with poor prognosis of BCVA. Three patients (15%) developed recurrence after treatment.

CONCLUSIONS

The prognosis of BCVA in HIV-infected patients with ocular syphilis in the ART era was favourable after proper treatment. Having >28 days of ocular symptoms before diagnosis was associated with poor prognosis. Changes in visual acuity in HIV-infected MSM should prompt an immediate assessment for ocular syphilis as delays in diagnosis and therapy can lead to irreversible visual loss.

Cost-effectiveness of HIV and syphilis antenatal screening: a modelling study

OBJECTIVES

The WHO called for the elimination of maternal-to-child transmission (MTCT) of HIV and syphilis, a harmonised approach for the improvement of health outcomes for mothers and children. Testing early in pregnancy, treating seropositive pregnant women and preventing syphilis reinfection can prevent MTCT of HIV and syphilis. We assessed the health and economic outcomes of a dual testing strategy in a simulated cohort of 100 000 antenatal care patients in Malawi.

METHODS

We compared four screening algorithms: (1) HIV rapid test only, (2) dual HIV and syphilis rapid tests, (3) single rapid tests for HIV and syphilis and (4) HIV rapid and syphilis laboratory tests. We calculated the expected number of adverse pregnancy outcomes, the expected costs and the expected newborn disability-adjusted life years (DALYs) for each screening algorithm. The estimated costs and DALYs for each screening algorithm were assessed from a societal perspective using Markov progression models. Additionally, we conducted a Monte Carlo multiway sensitivity analysis, allowing for ranges of inputs.

RESULTS

Our cohort decision model predicted the lowest number of adverse pregnancy outcomes in the dual HIV and syphilis rapid test strategy. Additionally, from the societal perspective, the costs of prevention and care using a dual HIV and syphilis rapid testing strategy was both the least costly ($226.92 per pregnancy) and resulted in the fewest DALYs (116 639) per 100 000 pregnancies. In the Monte Carlo simulation the dual HIV and syphilis algorithm was always cost saving and almost always reduced DALYs compared with HIV testing alone.

CONCLUSIONS

The results of the cost-effectiveness analysis showed that a dual HIV and syphilis test was cost saving compared with all other screening strategies. Updating existing prevention of mother-to-child HIV transmission programmes in Malawi and similar countries to include dual rapid testing for HIV and syphilis is likely to be advantageous.

Field evaluation of a dual rapid diagnostic test for HIV infection and syphilis in Lima, Peru

OBJECTIVES

Screening for HIV and syphilis in key populations is recommended by the WHO to reduce the morbidity, mortality and transmission associated with undiagnosed and untreated infections. Rapid point-of-care tests that can detect multiple infections with a single fingerprick whole blood specimen using a single device are gaining popularity. We evaluated the field performance of a rapid dual HIV and syphilis test in people at high risk of HIV and syphilis infections.

METHODS

Participants included men who have sex with men and transgender women recruited in Lima, Peru. Reference standard testing for detection of HIV and syphilis infections, conducted using blood samples from venipuncture, included Treponema pallidum particle agglutination and fourth-generation HIV enzyme immunoassay for which positive results had a confirmation HIV Western blot test. For the evaluation test, SD BIOLINE HIV/Syphilis Duo test (Standard Diagnostics, Korea), a fingerprick blood specimen was used. Sensitivity and specificity were calculated and the exact binomial method was used to determine 95% CIs.

RESULTS

A total of 415 participants were recruited for the study. The dual test sensitivity for detection of T. pallidum infection was 89.2% (95% CI 83.5% to 93.5%) and specificity 98.8% (95% CI 96.5% to 99.8%). For detection of HIV infection, the sensitivity of the dual test was 99.1% (95% CI 94.8% to 100%) and specificity 99.4% (95% CI 97.7% to 99.9%).

CONCLUSIONS

This high performing dual test should be considered for the use in clinical settings to increase uptake of simultaneous testing of HIV and syphilis and accelerate time to treatment for those who need it.

Secondary syphilis presenting with aortitis and coronary ostial occlusion

Aortitis is an established manifestation of tertiary syphilis. We report a rare case of aortitis with ostial occlusion and left ventricular failure in secondary syphilis. Her management required a true multidisciplinary approach from multiple specialities due to complications of concomitant psychosis and a history of anaphylaxis to penicillin. This case illustrates the complexities of diagnosing and managing a rare presentation of this increasingly prevalent infection.

Painful and multiple anogenital lesions are common in men with Treponema pallidum PCR-positive primary syphilis without herpes simplex virus coinfection: a cross-sectional clinic-based study

BACKGROUND

Chancres, the hallmark of primary syphilis, are classically described as single, painless ulcers at the site of Treponema pallidum inoculation. We aimed to determine the frequency of painful or multiple anogenital lesions of primary syphilis among men, whether there was concurrent herpes simplex virus (HSV) infection and whether HIV status altered clinical presentations.

METHODS

This study was conducted among men with T. pallidum PCR-positive lesions, attending a clinic in Melbourne, Australia, between 2009 and 2014. Lesions were also tested with HSV PCR, and syphilis serology undertaken.

RESULTS

183 men with T. pallidum PCR-positive primary anogenital lesions were included. 89% were men who have sex with men, and 10.9% were heterosexual. 38 men (20.8%) were HIV positive. Anal lesions were more common in HIV-positive men (34.2%) than in HIV-negative men (11.6%). Primary lesions were frequently painful (49.2%) or multiple (37.7%), and infrequently associated with HSV (2.7%). Of 37 men with both painful and multiple primary lesions, only 8% had concurrent HSV. Presentation was not significantly altered by HIV status.

CONCLUSIONS

Primary syphilis lesions are often painful and/or multiple in the absence of herpes coinfection, and may be clinically misdiagnosed.

Diagnostic accuracy of rapid tests for sexually transmitted infections in symptomatic women

OBJECTIVE

To determine the diagnostic accuracy of tests developed for use at the point of care for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and syphilis in women having symptoms of lower urinary tract infection.

METHODS

Cross-sectional study involving sexually active 14-49-year-old women with lower urinary tract infection symptoms consulting during 2010 at a private health clinic and at two public hospitals in Bogotá, Colombia. Pregnant women, those with a previous hysterectomy or those who received antibiotics during the previous 7 days were excluded. Sequential sampling was used; sample size: 1500 women. The ACON NG and CT duo test combo and the ACON individual test plates for NG and separately for CT were used. The QuickVue Chlamydia rapid test (RT) was also used. All of them were compared with nucleic acid amplification methods. The SD Bioline 3.0 and ACON test for syphilis were evaluated and compared with serological tests. Sensitivity and specificity were estimated.

RESULTS

CT RTs had a sensitivity that ranged between 22.7% and 37.7% and specificity between 99.3% and 100%. Sensitivity for NG with ACON Duo was 12.5% and specificity 99.8%. Tests for syphilis had a sensitivity of 91.6-100% and a specificity of 99.7-97.8%.

CONCLUSIONS

The RTs studied are not useful for screening for NG at the point of care. In case of CT a recommendation about their use in routine care should be supported by a cost-effectiveness analysis. In screening populations at high risk of sexually transmitted infections or pregnant women, the RTs for syphilis should be used.

Go big or go home: impact of screening coverage on syphilis infection dynamics

OBJECTIVES

Syphilis outbreaks in urban men who have sex with men (MSM) are an ongoing public health challenge in many high-income countries, despite intensification of efforts to screen and treat at-risk individuals. We sought to understand how population-level coverage of asymptomatic screening impacts the ability to control syphilis transmission.

METHODS

We developed a risk-structured deterministic compartmental mathematical model of syphilis transmission in a population of sexually active MSM. We assumed a baseline level of treatment of syphilis cases due to seeking medical care in all scenarios. We evaluated the impact of sustained annual population-wide screening coverage ranging from 0% to 90% on syphilis incidence over the short term (20 years) and at endemic equilibrium.

RESULTS

The relationship between screening coverage and equilibrium syphilis incidence displayed an inverted U-shape relationship, with peak equilibrium incidence occurring with 20-30% annual screening coverage. Annual screening of 62% of the population was required for local elimination (incidence <1 case per 100 000 population). Results were qualitatively similar in the face of differing programmatic, behavioural and natural history assumptions, although the screening thresholds for local elimination differed. With 6-monthly or 3-monthly screening, the population coverage required to achieve local elimination was reduced to 39% or 23%, respectively.

CONCLUSIONS

Although screening has the potential to control syphilis outbreaks, suboptimal coverage may paradoxically lead to a higher equilibrium infection incidence than that observed in the absence of intervention. Suboptimal screening programme design should be considered as a possible contributor to unsuccessful syphilis control programmes in the context of the current epidemic.

Clinical and epidemiological characteristics of patients with early syphilis from three academic centres in Poland, Germany and Ireland: initial findings from the POETS study

OBJECTIVES

Syphilis recognition in HIV-positive patients has important implications. Initial data from this study, established in June 2012 to better understand the natural history of syphilis and treatment response, examine the characteristics of patients including sexual behaviour, rates of concurrent sexually transmitted infections (STI) and type of treatment given.

METHODS

Patients were recruited from Ireland, Poland and Germany. Data gathered included demographics, method of syphilis acquisition, stage of syphilis infection, HIV status, nadir and current CD4 counts and HIV viral suppression rates. Data were then subanalysed into HIV-positive and HIV-negative groups.

RESULTS

Of 175 patients recruited, 68% were HIV-positive and 86.3% were men who have sex with men. Most HIV-positive patients presented with secondary syphilis (55.7% vs 13.2%) (p=0.0001) while the majority of HIV-negative patients had primary syphilis noted at the time of recruitment (47.2% vs18.9%, p=0.0002). Approximately half of all patients had a HIV RNA viral load <40 copies/mL (55%). Previous syphilis infection occurred more frequently in HIV-positive than HIV-negative patients (p=0.0001). Concurrent STIs at the time of syphilis diagnosis were found in 26.8%, of whom 31 (25.4%) were HIV-positive (p=0.64). HIV-positive patients received doxycycline more frequently than their HIV-negative counterparts (33.6% vs 1.9%, p=0.0001) while HIV-negative patients were treated with long-acting penicillin in 88.7% of cases vs 58% of HIV-positive patients (p=0.0002).

CONCLUSIONS

A 40% rate of unsuppressed viraemia, high levels of STIs and varying treatment regimens represent a public health risk for Europe, suggesting the model of sexual healthcare delivery in HIV-positive patients requires further evaluation.

Population and dyadic-based seroincidence of herpes simplex virus-2 and syphilis in southern India

Objectives

Herpes simplex virus-2 (HSV-2) and syphilis are associated with increased risk of HIV, highlighting the importance of understanding their transmission dynamics. In India, most studies of HSV-2 and syphilis incidence are in high-risk populations and may not accurately reflect infectious activity. In this study, we aim to define HSV-2/syphilis incidence and risk factors in a population sample.

Methods

We conducted a longitudinal population-based survey in Andhra Pradesh, India, in two rounds: 2004–2005 and 2010–2011. Sociodemographic and behavioural data were collected, and dried blood spots tested for HSV-2 and Treponema pallidum IgG. After calculating sexually transmitted infection (STI) incidence, associated factors were assessed using modified Poisson regression and within-couple transmission rates modelled using seroconcordance/discordance data.

Results

12 617 adults participated at baseline with 8494 at follow-up. Incidence of HSV-2 and syphilis per 1000 person-years was 25.6 (95% CI 24.1 to 27.2) and 3.00 (95% CI 2.52 to 3.54). Incidence of HSV-2 was higher in women vs men (31.1 vs 20.2) and in rural vs urban residents (31.1 vs 19.0) (p<0.05 for both). STI seroincidence increased in a step-wise fashion with age and was associated with spousal seropositivity for both sexes (incidence rate ratio (IRR) 2.59 to 6.78). Within couples the rate of transmission per 1000 couple-years from men to women vs women to men was higher for HSV-2 (193.3 vs 119.0) compared with syphilis (27.6 vs 198.8), p<0.05 for both.

Conclusions

HSV-2 has higher incidence among subpopulations such as women, rural residents and older-aged individuals, suggesting a need for more generalised STI prevention approaches among populations traditionally considered low risk.