Development of a real-time PCR assay to detect Treponema pallidum in clinical specimens and assessment of the assay's performance by comparison with serological testing

Assessing the risks for stillbirth in São Paulo, Brazil: protocol for a multidisciplinary case-control study - FetRisks

Stillbirth is a fundamental component of childhood mortality, but its causes are still insufficiently understood. This study aims to explore stillbirth risk factors by using a multidisciplinary approach to stimulate public policies and protocols to prevent stillbirth, improve maternal care and support bereaved families. METHODS AND ANALYSIS: In this case-control study with stillbirths and live births in 14 public hospitals in São Paulo, mothers are interviewed at hospitals after delivery, and hospital records and prenatal care registries are reviewed. Maternal and umbilical cord blood samples and placentas are collected to analyse angiogenesis and infection biomarkers, and the placenta's anatomopathological exam. Air pollutant exposure is estimated through the participant's residence and work addresses. Traditional and non-invasive autopsies by image-guided histopathology are conducted in a subset of stillbirths. Subsample mothers of cases are interviewed at home 2 months after delivery on how they were dealing with grief. Information contained in the official prenatal care registries of cases and controls is being compiled. Hospital managers are interviewed about the care offered to stillbirth mothers. Data analysis will identify the main risk factors for stillbirth, investigate their interrelations, and evaluate health services care and support for bereaved families. We hope this project will contribute to the understanding of stillbirth's risk factors and related health services in Brazil, providing new knowledge about this central public health problem, contributing to the improvement of public policies and prenatal and puerperal care, helping to prevent stillbirths and improve the healthcare and support for bereaved families. ETHICS AND DISSEMINATION: This study protocol was approved by the Ethics Committee of the Municipal Health Secretary (process no 16509319.0.3012.5551) and of the Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (process no 16509319.0.0000.0068). Results will be communicated to the study participants, policy-makers and the scientific community.

Modelling of doxycycline-based prevention of bacterial sexually transmitted infections in comparison to condom-based and test-based prevention

Background

Doxycycline-based prevention of bacterial sexually transmitted infections (STIs) has been assessed in various studies and has been recommended by the European AIDS Clinical Society to be proposed to persons with repeated STIs on a case-by-case basis. However, while good preventive effects could be shown for Chlamydia trachomatis and Treponema pallidum in Europe, no reliable prevention against doxycycline resistance-affected bacterial causes of STIs like Neisseria gonorrhoeae and Mycoplasma genitalium was confirmed.

Methods

In a modelling-approach, we assessed potential beneficial effects even against the latter microorganisms in case of optimized adherence with doxycycline prevention. These effects were modelled for Germany in comparison to traditional prevention schemes like condom-based STI-prevention and testing-as-prevention.

Results

With estimated risk reduction in the ranges of 86% for N. gonorrhoeae and of 82% for Mycoplasma genitalium, expectable preventive efficacy similar to alternative preventive approaches could be calculated in case of optimized adherence with doxycycline prevention. In case of repeated risk exposure, the preventive potential of condom-based prevention was decreased compared to both optimized doxycycline prevention and testing-as-prevention.

Conclusions

As suggested by the applied modelling, the preventive effect of optimized doxycycline prevention against bacterial STIs is in a similar range, like other common prevention strategies.

Treponema pallidum Detection at Asymptomatic Oral, Anal, and Vaginal Sites in Adults Reporting Sexual Contact with Persons with Syphilis

We investigated Treponema pallidum PCR positivity at mucosal sites (oral, anal, and vaginal sites) among adults who had sexual contact with a person with syphilis (syphilis contacts). All syphilis contacts had oral rinse and swab samples collected for testing. Men who have sex with men had anal swab and women had vaginal swab samples collected for testing, regardless of the presence of lesions. Of 407 persons tested, 42 (10%) had early syphilis diagnosed; of those, 19 (45%) tested positive by PCR from any anatomic site and had a positive serologic test. T. pallidum was positive from vaginal samples in 3 women, anal samples in 3 men, and oral cavity samples in 2 women and 3 men, without symptoms at those sites. Three women had no prior syphilis serologic test. T. pallidum detection at asymptomatic mucosal sites suggests early syphilis infections, particularly in cases that would conventionally be staged as latent syphilis of unknown duration.

Treponema pallidum PCR screening at mucosal sites of asymptomatic men who have sex with men taking HIV pre-exposure prophylaxis

Early detection and treatment of syphilis will reduce the infectious period and transmission. We aimed to determine whether screening men who have sex with men (MSM) taking HIV pre-exposure prophylaxis (PrEP) for syphilis using Treponema pallidum polymerase chain reaction (PCR) could detect syphilis before the appearance of syphilis antibodies in serology. MSM attending 3-monthly PrEP clinic visits in Melbourne, Australia, were screened with a PCR assay targeting the polA gene of T. pallidum from an anal swab and an oral rinse between November 2019 and March 2020. Participants were serologically screened for syphilis using chemiluminescence immunoassay. A total of 309 asymptomatic participants provided an anal swab and oral rinse sample for T. pallidum PCR screening. Two syphilis cases (0.6%) were detected: one man had a positive serology only; another man had T. pallidum detected by PCR from an anal swab and a positive serology. PCR positivity was 0.3% (n = 1) for anal swabs and 0% (n = 0) for oral rinse. In this study, T. pallidum PCR screening at routine PrEP clinic visits did not identify additional cases of early syphilis over serological screening performed at these visits. IMPORTANCE With the ongoing syphilis epidemic in men who have sex with men (MSM), we investigated the role of using Treponema pallidum polymerase chain reaction (PCR) testing at the oral cavity and anus in MSM taking pre-exposure prophylaxis for the early detection of syphilis. We evaluated whether the PCR tests from these mucosal sites can detect syphilis infection early, before the development of syphilis antibodies in serology. Our study found two syphilis cases among 309 MSM, and only one syphilis case had a positive anal PCR swab, although serology was positive. We conclude that additional PCR testing is likely to be expensive and would not be cost effective for individuals who regularly screen for syphilis. However, future studies with a larger sample size are required.

Screening for Resistant Bacteria, Antimicrobial Resistance Genes, Sexually Transmitted Infections and Schistosoma spp. in Tissue Samples from Predominantly Vaginally Delivered Placentae in Ivory Coast and Ghana

Medical complications during pregnancy have been frequently reported from Western Africa with a particular importance of infectious complications. Placental tissue can either become the target of infectious agents itself, such as, e.g., in the case of urogenital schistosomiasis, or be subjected to contamination with colonizing or infection-associated microorganisms of the cervix or the vagina during vaginal delivery. In the retrospective cross-sectional assessment presented here, the quantitative dimension of infection or colonization with selected resistant or pathogenic bacteria and parasites was regionally assessed. To do so, 274 collected placental tissues from Ivory Coastal and Ghanaian women were subjected to selective growth of resistant bacteria, as well as to molecular screening for beta-lactamase genes, Schistosoma spp. and selected bacterial causative agents of sexually transmitted infections (STI). Panton-Valentine-negative methicillin-resistant Staphylococcus aureus (MRSA) was grown from 1.8% of the tissue samples, comprising the spa types t008 and t688, as well as the newly detected ones, t12101 (n = 2) and t12102. While the culture-based recovery of resistant Enterobacterales and nonfermentative rod-shaped Gram-negative bacteria failed, molecular assessments confirmed beta-lactamase genes in 31.0% of the samples with multiple detections of up to four resistance genes per sample and blaCTX-M, blaIMP, blaGES, blaVIM, blaOXA-58-like, blaNDM, blaOXA-23-like, blaOXA-48-like and blaKPC occurring in descending order of frequency. The beta-lactamase genes blaOXA-40/24-like, blaNMC_A/IMI, blaBIC, blaSME, blaGIM and blaDIM were not detected. DNA of the urogenital schistosomiasis-associated Schistosoma haematobium complex was recorded in 18.6% of the samples, but only a single positive signal for S. mansoni with a high cycle-threshold value in real-time PCR was found. Of note, higher rates of schistosomiasis were observed in Ghana (54.9% vs. 10.3% in Ivory Coast) and Cesarean section was much more frequent in schistosomiasis patients (61.9% vs. 14.8% in women without Schistosoma spp. DNA in the placenta). Nucleic acid sequences of nonlymphogranuloma-venereum-associated Chlamydia trachomatis and of Neisseria gonorrhoeae were recorded in 1.1% and 1.9% of the samples, respectively, while molecular attempts to diagnose Treponema pallidum and Mycoplasma genitalium did not lead to positive results. Molecular detection of Schistosoma spp. or STI-associated pathogens was only exceptionally associated with multiple resistance gene detections in the same sample, suggesting epidemiological distinctness. In conclusion, the assessment confirmed considerable prevalence of urogenital schistosomiasis and resistant bacterial colonization, as well as a regionally expected abundance of STI-associated pathogens. Continuous screening offers seem advisable to minimize the risks for the pregnant women and their newborns.

An evaluation of a multiplex PCR assay for the detection of Treponema pallidum, HSV-1, and HSV-2

Multiplex PCR can utilize limited clinical material and is more cost-effective and expected to be used for the detection of Treponema pallidum, herpes simplex virus type 1 and 2 (HSV-1,2). We established a multiplex TP-HSV1-HSV2 Polymerase Chain Reaction (multiplex PCR) targeting the conserved regions of the PolA gene of TP and the UL42 gene of HSV1 and HSV2 to test skin lesions of 115 patients suspected of having TP and HSV1/2 infections. The laboratory sensitivities for all 3 pathogens were 300 copies/mL. The overall clinical sensitivity and specificity in secretion samples for TP were 91.7% and 100%, for HSV1 100% and 98%, and for HSV2 89.7% and 100%, respectively. The method appears superior in patients suspected of early TP infection but negative for nontreponemal antibody testing, and the method is also useful for the differential diagnosis of new skin lesions on genital, perianal, and oral sites of patients with a history of previous syphilis.

Advances in Diagnostics of Sexually Transmitted Infections

Sexually transmitted infections (STIs) are caused by various pathogens, many of which have common symptoms. Diagnostic tests are critical to supporting clinical evaluations in making patient management decisions. Molecular diagnostics are the preferred test type when available, especially in asymptomatic patients for many STIs. However, for some infections, serology offers the best insight into infectious status. Clinicians should be aware of the performance characteristics of the available STI diagnostic tests and understand how to use them. Point-of-care tests are helpful to implement rapid and accurate treatment responses, which are particularly helpful in certain at-risk populations.

Specific detection of Treponema pallidum in clinical samples: validation of a qPCR assay combining two genomic targets

OBJECTIVES

We evaluated a real-time quantitative PCR (qPCR) for detection of the Treponema pallidum (TP) genome in clinical samples through simultaneous detection of two genomic targets.

METHODS

We performed qPCR with TaqMan technology using two TP genes, polA and tpp47, as targets, with an internal positive control. The qPCR assay was compared with syphilis diagnosis based on a combination of clinical examination, serological results and inhouse nested PCR (nPCR). Samples were analysed at the National Reference Center for STIs at Cochin Hospital in Paris.

RESULTS

In total, from October 2010 to December 2016, 320 documented clinical samples (mucosal and cutaneous swabs) were collected from patients with or without syphilis attending STI centres in France. The qPCR had an overall sensitivity of 89% (95% CI 85.1% to 92.1%), a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 88% (95% CI 84.3% to 91.5%). The agreement between qPCR and nPCR results was 94% (κ=0.88, 95% CI 0.83 to 0.93). Calibration of the qPCR assay, by cloning both the polA and tpp47 genes, defined the detection threshold as 1 copy/µL of DNA elution.

CONCLUSIONS

We validated a new qPCR for detecting the TP genome in clinical samples with excellent sensitivity and specificity. The cloning of polA and tpp47 genes for calibration would be interesting in the evaluation of bacterial loads in samples.

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.

Diagnosis and treatment of syphilis: 2019 Belgian National guideline for primary care

OBJECTIVES

In the last 10 years, Belgium and countries of the European Economic Area and other high-income countries observed an increasing trend in syphilis diagnoses. Men who have sex with men (MSM) are the most affected population explained by high rates of unprotected sex, a greater number of sexual partners, and risk compensation as a result of pre-exposure prophylaxis use. The 2019 European Centre for Disease Prevention and Control (ECDC) technical report on syphilis proposed interventions such as enhanced screening of specific populations at risk. This guideline will address these issues.

METHODS

We performed a systematic review of the evidence for diagnosing and treating syphilis.

RESULTS

Based on the results, recommendations were formulated for primary health care professionals in Belgium. This syphilis guideline addresses prioritised testing, the sample and test for the diagnosis, the treatment of a person with syphilis including syphilis serology follow-up, and partner management.

CONCLUSION

The identification and management of patients with syphilis will benefit from the application of this guideline.

Detection of Treponema pallidum DNA during early syphilis stages in peripheral blood, oropharynx, ano-rectum and urine as a proxy for transmissibility

Background

Syphilis diagnosis may be challenging, especially in the asymptomatic and early clinical stages. We evaluated the presence of Treponema pallidum DNA (TP-DNA) in various sample types to elucidate transmissibility during various syphilis stages.

Methods

The study was conducted at the Amsterdam Centre for Sexual Health. We included adult men who have sex with men (MSM), who were suspected of having syphilis. The 2020 European guidelines definitions were followed for the diagnosis and staging of syphilis. Using a polymerase chain reaction (PCR) targeting the polA gene of Treponema pallidum (TP-PCR), we tested the following study samples on TP-DNA: peripheral blood, oropharyngeal swab, ano-rectal swab, and urine.

Results

From November 2018 to December 2019 we included 293 MSM. Seventy clients had primary syphilis, 73 secondary syphilis, 86 early latent syphilis, 14 late latent syphilis, 23 treated syphilis, and 27 had no syphilis. TP-DNA was detected in at least 1 study sample in 35/70 clients with primary syphilis (2/70 peripheral blood, 7/70 oropharynx, 13/70 ano-rectum, and 24/70 urine); in 62/73 clients with secondary syphilis (15/73 peripheral blood, 47/73 oropharynx, 37/73 ano-rectum, and 26/73 urine); and in 29/86 clients with early latent syphilis (5/86 peripheral blood, 21/86 oropharynx, 11/86 ano-rectum, and 6/86 urine). TP-DNA was not detected in clients with late latent syphilis or treated syphilis, nor in clients without syphilis.

Conclusions

TP-DNA was frequently detected in various sample types in the absence of lesions. This is in line with the high transmission rate of syphilis and opens diagnostic opportunities for early presymptomatic syphilis stages.

Clinical Presentation of Incident Syphilis Among Men Who Have Sex with Men Taking HIV Pre-Exposure Prophylaxis in Melbourne, Australia

BACKGROUND

Current international guidelines on human immunodeficieny virus (HIV) Pre-Exposure Prophylaxis (PrEP) recommend serological screening for syphilis at routine 3-monthly PrEP appointments. The aim of our study was to describe the pattern of clinical presentation of syphilis among men who have sex with men (MSM) taking PrEP. We were interested in whether syphilis is detected through screening at scheduled3-monthly PrEP clinic appointments or whether primary or secondary syphilis presented at unscheduled interval visits.

METHODS

This was a retrospective study of MSM attending the PrEP clinic at the Melbourne Sexual Health Centre between February 2016 and March 2019. Serological screening for syphilis was routinely undertaken at 3-monthly PrEP clinic appointments. Diagnoses of early syphilis were identified from PrEP clinic visits and from interim walk-in STI clinic attendances.

RESULTS

There were 69 cases of early syphilis among 61 MSM taking PrEP during the study period. There were 24 (35%) primary, 16 (23%) secondary, and 29 (42%) early latent infections. The incidence of early syphilis was 8.6 per 100 person-years. A substantial proportion of primary (58%) and secondary (44%) syphilis diagnoses were made at interim STI clinic attendances, between PrEP appointments.

CONCLUSIONS

Syphilis screening at routine 3-monthly PrEP visits alone fails to detect a proportion of primary and secondary syphilis infections and may be insufficient in preventing onward transmission. Education of MSM taking PrEP regarding the risk of syphilis and symptom recognition is necessary together with access to syphilis testing between PrEP visits.

Comparative Analysis of Molecular and Serologic Testing for Primary Syphilis: A Population-Based Cohort Study

Rising rates of syphilis (T. pallidum; Tp) requires rapid diagnosis and treatment to manage the growing epidemic. Syphilis serology is imperfect and requires interpretation of multiple tests while molecular diagnostics allows for potential yes-no identification of highly infective, primary anogenital lesions. Accuracy of this testing modality has thus far been limited to small, highly selective studies. Therefore, we retrospectively assessed a large, adult population of patients with anogenital lesions seen at Sexually Transmitted Infection (STI) clinics in Alberta, Canada who were screened for syphilis and herpes simplex (HSV) 1/2 using PCR to evaluate Tp-PCR versus serology to diagnose primary syphilis. 114 (3.1%) of the 3,600 adult patients had at least one Tp-PCR+ anogenital lesion with 99 (2.8%) patients having newly positive syphilis serology (new INNO-LIA positive or 4-fold RPR increase). Tp-PCR had a sensitivity of 49.3% (95% CI 42.6-56.1) and specificity of 99.9% (99.7-100.0). Positive predictive values and negative predictive values in the study population or when corrected for provincial prevalence were 97.4% (92.5-99.5) or 0.4% (0.4-1.2) and 96.7% (96.1-97.3) or 100.0% (100.0-100.0), respectively. Positive and negative likelihood ratios were estimated at 555 (178-1733) and 0.5 (0.4-0.6), respectively. Review of all Tp-PCR performed with or without exclusion of HSV-positive lesions resulted in no significant change in Tp-PCR characteristics. Interestingly, 12 of the Tp-PCR+ samples had negative serology at time of lesion sampling but became positive within our 28-day testing window. Overall, this study further supports the use of Tp-PCR as an accurate assay to rapidly identify, treat, and prevent the spread of primary syphilis.

Treponema pallidum detection in lesion and non-lesion sites in men who have sex with men with early syphilis: a prospective, cross-sectional study

BACKGROUND

Syphilis transmission is increasing, and precisely how Treponema pallidum is transmitted sexually from person to person is unclear. We aimed to determine the frequency of T pallidum shedding from potentially asymptomatic sites and the stage of infection at which shedding is most frequent in men who have sex with men (MSM), who have been disproportionately affected by syphilis.

METHODS

We did a prospective, cross-sectional study in MSM recruited from Melbourne Sexual Health Centre (Melbourne, VIC, Australia). Men were eligible if they were aged 18 years or older, reported sex with men during the past 12 months, and had laboratory confirmed primary, secondary, or early latent syphilis, consistent with Australian definitions. Primary and secondary syphilis lesions were swabbed and non-lesion samples were collected via oral rinse, oral cavity swab, anal canal swab, urine, and semen. Samples were tested for T pallidum using PCR assays targeting polA (lesion and non-lesion samples) and 47 kDa (non-lesion samples only) gene targets. The primary outcome was the proportion of men with T pallidum detected from potentially asymptomatic sites-namely, the mouth, anus, urethra, and semen.

FINDINGS

Between Nov 30, 2015, and May 23, 2019, 246 MSM were screened for inclusion, of whom 200 had serologically confirmed early syphilis and were included in the study: 54 (27%) of 200 had primary syphilis, 93 (47%) had secondary syphilis, and 53 (27%) had early latent syphilis. T pallidum DNA was detected in 48 (24%; 95% CI 18·3-30·5) of 200 men by oral rinse or oral lesion swab, or both, of whom 24 had no oral lesions. Oral T pallidum detection was most frequent in those with secondary syphilis compared with those at other stages of disease (41 [44%] of 93 vs seven [7%] of 107; p<0·0001), and in men with rapid plasma reagin titres of 1/64 or higher compared with those with lower titres (37 [32%] of 117 vs 11 [13%] of 83; p=0·0026). T pallidum was detected by anal canal swab or anal lesion swab, or both, in 45 (23·0%; 95% CI 17·3-29·5) of 196 men with available samples, of whom ten had no anal lesion. Furthermore, T pallidum was detected in urine samples of 12 (6·1%, 3·2-10·3) of 198 men and in semen samples from six (12·0%, 4·5-24·3) of 50 men who provided samples. Among the 93 men with secondary syphilis, 69 (74%) had T pallidum detected at any site, and 24 (26%) had detection at two or more separate sites. Among the 54 men with primary syphilis, 49 (91%) had T pallidum detected at any site, and 11 (20%) had detection at two or more separate sites. Among the 53 men with early latent syphilis, four (8%) had T pallidum detected at any site and none had T pallidum detected at two or more separate sites.

INTERPRETATION

Unrecognised oral and anal shedding of T pallidum occurs in MSM with early syphilis, most frequently in those with secondary syphilis, suggesting secondary syphilis is the most infectious stage and that earlier detection and treatment of syphilis to prevent progression to the secondary stage might improve syphilis control. Future research is needed to ascertain the contribution of shedding of T pallidum from non-lesion sites to transmission of syphilis.

FUNDING

Australian National Health and Medical Research Council.

Timing of primary syphilis treatment and impact on the development of treponemal antibodies: a cross-sectional clinic-based study

BACKGROUND

Serology is negative in a proportion of primary syphilis cases where Treponema pallidum PCR testing is positive. We aimed to identify discordant, T. pallidum PCR-positive, serology-negative primary syphilis cases and any clinical or laboratory factors associated with failure to subsequently seroconvert.

METHODS

Serodiscordant primary syphilis cases that were T. pallidum PCR-positive and serology-negative (including rapid plasma reagin, T. pallidum particle agglutination, T. pallidum enzyme immunoassay or T. pallidum chemiluminescence assay) were identified from the Melbourne Sexual Health Centre electronic records between April 2011 and December 2019. Clinical and laboratory associations were examined.

RESULTS

There were 814 primary syphilis cases in the study period and 38 (4.7%) were serodiscordant, 35 in men who have sex with men. Thirty-two had follow-up serology performed a median of 24 days later, of which 16 (50%) seroconverted, mostly (81%) within 6 weeks. Failure to seroconvert was significantly associated with treatment on day 1. Of the 12 cases treated on day 1, 10 (83%) failed to seroconvert compared with 6 of 20 (30%) among those who were treated after day 1.

DISCUSSION

Earlier treatment of primary syphilis can prevent the development of serological markers. T. pallidum PCR can identify primary syphilis lesions before the development of serological markers and improve diagnosis of early primary syphilis lesions. Serology alone will miss a proportion of primary syphilis infections and should be repeated if a diagnosis of syphilis is being considered.

Use of a Multiplex PCR Assay To Assess the Presence of Treponema pallidum in Mucocutaneous Ulcerations in Patients with Suspected Syphilis

We evaluated the utility of the commercial Allplex genital ulcer real-time PCR multiplex assay for detecting Treponema pallidum, herpes simplex virus 1 (HSV-1) and 2 (HSV-2), and Chlamydia trachomatis serovar L (lymphogranuloma venereum [LGV]) DNA in mucosal and genital ulcers in the context of suspected syphilis. In total, 374 documented genital and mucosal ulcers from patients with and without syphilis presenting at several sexually transmitted infection (STI) centers in France from October 2010 to December 2016 were analyzed at the National Reference Center (CNR) for Bacterial STIs at Cochin Hospital in Paris. T. pallidum subsp. pallidum detection results were compared with the final diagnosis based on a combination of clinical examination, serological results, and in-house nested PCR (nPCR). Detections of HSV and LGV were validated against reference methods. We found that 44.6% of the 374 samples tested were positive for T. pallidum subsp. pallidum, 21% for HSV, and 0.8% for LGV. No positive results were obtained for 30.7% of samples, and 4.8% presented coinfections. For T. pallidum subsp. pallidum detection, the overall sensitivity was 80% (95% confidence interval [CI], 76.1 to 84.1%), specificity was 98.8% (95% CI, 97.7 to 99.9%), positive predictive value was 98.8% (95% CI, 97.7 to 99.9%) and negative predictive value was 80.2% (95% CI, 76.2 to 84.2%), with a rate of concordance with the reference method of 92.5% (k = 0.85). This PCR multiplex assay is suitable for T. pallidum subsp. pallidum detection in routine use and facilitates the simultaneous rapid detection of a broad panel of pathogens relevant in a context of suspected syphilis lesions.

Geographically structured genomic diversity of non-human primate-infecting Treponema pallidum subsp. pertenue

Many non-human primate species in sub-Saharan Africa are infected with Treponema pallidum subsp. pertenue, the bacterium causing yaws in humans. In humans, yaws is often characterized by lesions of the extremities and face, while T. pallidum subsp. pallidum causes venereal syphilis and is typically characterized by primary lesions on the genital, anal or oral mucosae. It remains unclear whether other T. pallidum subspecies found in humans also occur in non-human primates and how the genomic diversity of non-human primate T. pallidum subsp. pertenue lineages is distributed across hosts and space. We observed orofacial and genital lesions in sooty mangabeys (Cercocebus atys) in Taï National Park, Côte d'Ivoire and collected swabs and biopsies from symptomatic animals. We also collected non-human primate bones from 8 species in Taï National Park and 16 species from 11 other sites across sub-Saharan Africa. Samples were screened for T. pallidum DNA using polymerase chain reactions (PCRs) and we used in-solution hybridization capture to sequence T. pallidum genomes. We generated three nearly complete T. pallidum genomes from biopsies and swabs and detected treponemal DNA in bones of six non-human primate species in five countries, allowing us to reconstruct three partial genomes. Phylogenomic analyses revealed that both orofacial and genital lesions in sooty mangabeys from Taï National Park were caused by T. pallidum subsp. pertenue. We showed that T. pallidum subsp. pertenue has infected non-human primates in Taï National Park for at least 28 years and has been present in two non-human primate species that had not been described as T. pallidum subsp. pertenue hosts in this ecosystem, western chimpanzees (Pan troglodytes verus) and western red colobus (Piliocolobus badius), complementing clinical evidence that started accumulating in Taï National Park in 2014. More broadly, simian T. pallidum subsp. pertenue strains did not form monophyletic clades based on host species or the symptoms caused, but rather clustered based on geography. Geographical clustering of T. pallidum subsp. pertenue genomes might be compatible with cross-species transmission of T. pallidum subsp. pertenue within ecosystems or environmental exposure, leading to the acquisition of closely related strains. Finally, we found no evidence for mutations that confer antimicrobial resistance.

A retrospective study on nested PCR detection of syphilis treponemes in clinical samples: PCR detection contributes to the diagnosis of syphilis in patients with seronegative and serodiscrepant results

Syphilis, caused by Treponema pallidum ssp. pallidum (TPA), is a persisting global health problem. Although syphilis diagnostics relies mainly on serology, serological tests have some limitations, and it is recommended that the final diagnosis be supported by additional tests. The purpose of this study was to analyze the relationship between serology and PCR in syphilis diagnostics. From the year 2004 to May 2019, a total of 941 samples were taken from 833 patients suspected of having syphilis, in Czech Republic. In all these samples, both nested PCR detection of TPA and serology testing were performed. Of the 941 samples, 126 were seronegative, 651 were seropositive, and 164 were serodiscrepant. Among seronegative samples (n = 126), 11 were PCR-positive (8.7%). Among seropositive samples (n = 651; i.e., samples positive for both non-treponemal and treponemal serology tests), 368 samples were PCR-positive (56.5%). The remaining 164 serodiscrepant samples included RPR negative and treponemal serological test-positive samples (n = 154) and a set of 10 RPR-positive samples negative in treponemal serological tests. While the first group revealed 73 PCR-positive samples (47.4%), the second revealed 5 PCR positive samples (50.0%). PCR detection rates were highest in primary syphilis, with lower rates in the secondary and undetermined syphilis stages. As shown here, the nested PCR can improve diagnostics of syphilis, especially in seronegative patients and in patients with discrepant serology.

Atypical manifestations of recent syphilis: study of 19 cases

Background

Syphilis is one of the most common diseases that start with genital ulcers. Aside from the initial, classic ulcerative lesion of syphilis, called hard chancre, atypical presentations are common, with erosions, erythema, edema, balanitis, and other dermatological manifestations. Associated with initial genital lesions, the presence of inguinal adenopathies is frequent, and the presence of hardened and painless lymphangitis on the dorsum of the penis is rare.

Objectives

To describe atypical penile manifestations in patients with early syphilis.

Methods

The present study reports patients who developed cord-like lesions on the penis.

Results

The study included 25 patients with cord-like lesions on the penis; in 19 of those, the diagnosis of syphilis was confirmed.

Study limitations

Small number of patients included.

Conclusions

In view of the findings of the present investigation, it is important to emphasize that all patients who present with cord-like lesions on the penis must undergo a rapid test for syphilis, VDRL, serologies for HIV viral hepatitis B and C and, whenever possible, histopathological and Doppler exams.

Epidemic of venereal treponematosis in wild monkeys: a paradigm for syphilis origin

Treponema pallidum infections have been primarily known as slightly contagious mucocutaneous infections called yaws (tropical Africa and America) and bejel (subtropical North Africa). T. pallidum emerged as a highly infectious venereal syphilis agent in South America, probably about 500 years ago, and because of its venereal transmission, it quickly caused a worldwide pandemic. The disease manifests as lesions, including a chancre; then antibodies become detectable when or slightly after the chancre appears, and before the development of a rash and other systemic manifestations. Venereal diseases are poorly known in monkeys. During fieldwork in Senegal, we discovered an epizootic outbreak of venereal disease that we explored. We detected a venereal form of T. pallidum subsp. pertenue infection in green monkeys (Chlorocebus sabaeus), then observed an epizootic outbreak in Senegal and its spread among baboons a year later. Comparative analysis of T. pallidum genomes from the monkeys' chancres and other Treponema genomes showed an acceleration of the number of single nucleotide polymorphisms, comparable to that observed in syphilis. Identified T. pallidum clones seem to be epizootic through the acceleration of their mutation rate, which is linked to their larger diffusion.

A Novel Nested Real-time Polymerase Chain Reaction for Treponema pallidum DNA in Syphilis Biospecimens

BACKGROUND

Early diagnosis of Treponema pallidum infection is helpful for disease management, and conventional PCR is suitable for lesion swabs of patients with probable early syphilis. We thus tested nested and real-time PCR (NR-PCR) in various biosamples from syphilitic patients.

METHODS

Samples were collected from syphilis patients before treatment. Specific primer sequences targeting the T. pallidum gene polA were designed for NR-PCR.

RESULTS

Across syphilis types, most samples assayed with NR-PCR returned a positive result, including earlobe blood (92.0%), cerebrospinal fluid (CSF) (90.2%), lesion swabs (74.3%), serum (66.9%), and whole blood (64.2%). No significant differences were observed in positive samples for whole blood, serum, and lesion swabs between primary and secondary syphilis (P > 0.05 for all comparisons). However, more whole-blood samples from patients with secondary syphilis were positive for NR-PCR than whole blood samples from patients with tertiary and latent syphilis (P < 0.05 for all comparisons). For neurosyphilis patients, significantly more earlobe blood samples tested positive than did whole-blood samples (P < 0.05), but there was no difference in positive results for earlobe blood and whole blood in latent syphilis. Significantly more serum samples tested positive in latent syphilis patients with rapid plasma regain (RPR) titers of 1:8 or greater, compared to those with RPR of 1:4 or less.

CONCLUSIONS

Nested and real-time PCR can be used to identify T. pallidum DNA in biosamples from syphilitic patients, especially earlobe blood.

Clinical Characteristics of Anorectal Mycoplasma genitalium Infection and Microbial Cure in Men Who Have Sex With Men

BACKGROUND

We report clinical characteristics of proctitis caused solely by Mycoplasma genitalium (MG) compared with chlamydia and gonococcus. We determined the proportions cured with first-line (azithromycin) and second-line antimicrobials (moxifloxacin, pristinamycin).

METHODS

A total of 166 patients attending Melbourne Sexual Health Centre from 2012 to 2016 with symptoms of proctitis were tested for MG, Chlamydia trachomatis, and Neisseria gonorrhoeae. Demographic characteristics, sexual behaviors, clinical symptoms, and signs were recorded. Multinomial multivariable logistic regression was used to test for significant differences in symptoms and signs for the pathogens detected.

RESULTS

Seventeen percent of men had MG (95% confidence interval, 12-24), 21% had chlamydia (15-27), and 40% had gonococcal monoinfection (32-48), whereas 22% had MG coinfection (16-29). Relative to men with MG monoinfection, those with chlamydial monoinfection reported more anal pain (adjusted prevalence odds ratio (aPOR), 4.68 [1.41-14.19]), whereas men with gonococcal monoinfection reported more anal pain (aPOR, 6.75 [2.21-20.55]) and tenesmus (aPOR, 15.44 [1.62-146.90]), but less anal itch (aPOR, 0.32 [0.11-0.93]). The microbiological cure for MG using azithromycin was low at 35% (22-50), whereas moxifloxacin subsequently cured 92% (64-100) and pristinamycin cured 79% (54-94) of infections.

CONCLUSIONS

M. genitalium was almost as common as chlamydia in men presenting to a sexual health center with symptoms of proctitis. Men with anorectal MG monoinfection were less likely to have symptoms and signs compared with those with chlamydia or gonococcus monoinfection. Cure for men with symptomatic anorectal MG by azithromycin was low. We suggest routine testing for MG in cases of proctitis, with test of cure after treatment being essential.

A Metataxonomic Tool to Investigate the Diversity of Treponema

The genus Treponema contains a number of human and animal pathogenic as well as symbiotic bacteria that are found in vastly different anatomical and environmental habitats. Our understanding of the species range, evolution, and biology of these important bacteria is still limited. To explore the diversity of treponemes, we established, validated, and tested a novel metataxonomic approach. As the informative nature of the hypervariable regions of the 16S rRNA gene differ, we first analyzed each variable region independently. Considering the in silico results obtained, we established and validated the sequencing of the V4-region of the 16S rRNA gene using known mixtures of Treponema species as well as a selected number of clinical samples. The metataxonomic approach was able to identify Treponema to a near-species level. We demonstrate that using a spirochete-specific enrichment, our method is applicable to complex microbial communities and large variety of biological samples. The metataxonomic approach described provides a useful method to unravel the full diversity and range of Treponema in various ecosystems.

Tropical rainforest flies carrying pathogens form stable associations with social nonhuman primates

Living in groups provides benefits but also incurs costs such as attracting disease vectors. For example, synanthropic flies associate with human settlements, and higher fly densities increase pathogen transmission. We investigated whether such associations also exist in highly mobile nonhuman primate (NHP) Groups. We studied flies in a group of wild sooty mangabeys (Cercocebus atys atys) and three communities of wild chimpanzees (Pan troglodytes verus) in Taï National Park, Côte d'Ivoire. We observed markedly higher fly densities within both mangabey and chimpanzee groups. Using a mark-recapture experiment, we showed that flies stayed with the sooty mangabey group for up to 12 days and for up to 1.3 km. We also tested mangabey-associated flies for pathogens infecting mangabeys in this ecosystem, Bacillus cereus biovar anthracis (Bcbva), causing sylvatic anthrax, and Treponema pallidum pertenue, causing yaws. Flies contained treponemal (6/103) and Bcbva (7/103) DNA. We cultured Bcbva from all PCR-positive flies, confirming bacterial viability and suggesting that this bacterium might be transmitted and disseminated by flies. Whole genome sequences of Bcbva isolates revealed a diversity of Bcbva, probably derived from several sources. We conclude that flies actively track mangabeys and carry infectious bacterial pathogens; these associations represent an understudied cost of sociality and potentially expose many social animals to a diversity of pathogens.

Sensitive detection of Treponema pallidum DNA from the whole blood of patients with syphilis by the nested PCR assay

The aim of this work was to investigate the application of the nested PCR assay for the detection of Treponema pallidum (TP) DNA from the blood of patients with different stages of syphilis. In this study, a nested PCR method targeting the Tpp47 and polA genes (Tpp47-Tp-PCR and polA-Tp-PCR) was developed to detect TP-DNA in whole blood samples collected from 262 patients with different stages of syphilis (84 primary syphilis, 97 secondary syphilis, and 81 latent syphilis patients). The PCR assay detected T. pallidum DNA in 53.6% and 62.9% of the patients with primary and secondary syphilis, respectively, which was much higher than the detection levels in patients with latent syphilis (7.4%) (both p < 0.001). For primary syphilis, a low RPR (0–16) was correlated with a higher detection rate of TP-DNA, whereas for secondary syphilis, the higher detection rate of blood TP-DNA was correlated with higher blood RPR titers (at or beyond 32). For latent syphilis, TP-DNA was only detectable by PCR in the early phase of the latent infection. Thus, blood RPR titers were correlated with the blood T. pallidum burden, but the correlations varied with primary and secondary syphilis. The results indicate that nested PCR is a sensitive method for detecting blood TP-DNA and is especially useful for detecting early syphilis including primary syphilis and secondary syphilis. The findings also suggest that the PCR assay may be used to complement other methods to enhance the diagnosis of syphilis.

Detección de Treponema pallidum subespecie pallidum para el diagnóstico de sífilis congénita mediante reacción en cadena de la polimerasa anidada

Introducción. La sífilis es una enfermedad producida por Treponema pallidum subespecie pallidum cuya incidencia mundial es de 12 millones de casos por año, aproximadamente; de estos, más de dos millones se presentan en mujeres gestantes, siendo la sífilis congénita la complicación más grave de esta infección en el embarazo.Objetivo. Detectar la presencia de T. pallidum subespecie pallidum en muestras clínicas para el diagnóstico de sífilis congénita mediante reacción en cadena de la polimerasa (PCR) anidada y determinar su concordancia con las pruebas serológicas.Materiales y métodos. Mediante PCR convencional y anidada, se amplificaron tres genes diana (polA, 16S ADNr y TpN47) y se confirmaron los productos de amplificación de los genes TpN47 y polA por secuenciación. Las pruebas serológicas empleadas fueron la VDRL (Venereal Disease Research Laboratory), la de reagina plasmática rápida (Rapid Plasma Reagin, RPR) y la de aglutinación de partículas para Treponema pallidum (Treponema pallidum Particle Agglutination Assay, TPPA).Resultados. La sensibilidad para la PCR convencional fue de 52 pg y, para la PCR anidada, de 0,52 pg. La especificidad con los iniciadores TpN47 y polA fue de 100 %; los resultados de la secuenciación mostraron una identidad de 97 % con T. pallidum. En 70 % de las muestras, los resultados de las pruebas serológicas y la PCR anidada concordaron.Conclusión. El gen TpN47 resultó ser el mejor blanco molecular para la identificación de T. pallidum. La PCR anidada se presenta como una alternativa de diagnóstico molecular promisoria para el diagnóstico de sífilis congénita.

Clinical factors associated with syphilis concordance in men in sexual partnerships: a cross-sectional couples study

BACKGROUND

Syphilis infections continue to increase among men who have sex with men (MSM) in many countries, with rates often higher among HIV-positive MSM. There is limited understanding of the risk and determinants of syphilis transmission between men. We aimed to examine the concordance of early syphilis infection between male sexual partners and clinical factors associated with transmission.

METHODS

Men attending Melbourne Sexual Health Centre with their male partners, where at least one was diagnosed with early syphilis, were identified from linkage of partner records between March 2011 and April 2016. Early latent syphilis was defined as a new asymptomatic syphilis presentation of less than 2 years' duration. Associations between concordance and potential risk factors were examined using Fisher's exact test.

RESULTS

Among 43 couples (86 men) identified, there were 13 couples (26 men) where both were diagnosed with early syphilis, representing a concordance rate of 30.2% (95% CI 17.2% to 46.1%). Among the 13 concordant couples, 5 men had primary syphilis (4 penile, 1 anal), 11 secondary syphilis (8 generalised rash, 3 penile, 2 anal, 1 oral lesion) and 10 early latent infections. Concordance was higher among couples where at least one partner had secondary syphilis compared with couples where neither partner had secondary syphilis (53% (9/17) vs 15% (4/26), P=0.016). Furthermore, concordance was higher among couples where one was HIV positive compared with couples where both were HIV negative (62% (5/8) vs 23% (8/35), P=0.042).

CONCLUSIONS

There was an overall concordance rate of 30%. Higher concordance rates for early syphilis infection between male sexual partners were associated with HIV and secondary syphilis.

Cross-sectional study of Treponema pallidum PCR in diagnosis of primary and secondary syphilis

BACKGROUND

Syphilis remains a major challenge and a complex diagnosis. We aim to evaluate the role of polymerase chain reaction (PCR) in Treponema pallidum (Tp) detection in various types of biological samples in the diagnosis of early syphilis.

METHODS

We conducted a cross-sectional study including all attendees of the STI clinic with clinical suspicion of early syphilis. One or more specimens for the detection of Tp by PCR testing were collected.

RESULTS

The overall sensitivity of Tp PCR test was 82.61% (95% CI: 68.6-92.2%). Tp PCR test had sensitivity of 84.6% (95% CI: 54.6-98.1%) in primary syphilis cases and 81.8% (95% CI: 64.5-93%) in secondary syphilis cases. PCR test performance was independent of HIV status.

CONCLUSION

Tp PCR test is a fast and reliable method for the detection of Tp in skin lesions of early syphilis, and it is a powerful tool in clinical settings.

Treponema pallidum ssp. pallidum identification by real-time PCR targetting the polA gene in paraffin-embedded samples positive by immunohistochemistry

Syphilis is a systemic and sexually transmitted infection caused by Treponema pallidum ssp. pallidum. This spirochete causes different clinical and subclinical stages depending on the duration of infection and immune status of the host. Several tests have been developed for diagnosis, and are classified into direct and indirect methods. The first one includes dark field microscopy, direct fluorescent antibody test in fluids or tissue, and molecular biology techniques. In the indirect method (serologic), the routine tests are used, and are divided in two categories: non-treponemal and treponemal ones. The objective of this work was to identify T. pallidum ssp. pallidum in paraffin-embedded skin biopsies positive by immunohistochemistry, using conventional polymerase chain reaction (PCR) and quantitative real time PCR (qPCR). We included a sample of 17 paraffin-embedded biopsies. DNA was extracted and processed by conventional PCR and real-time PCR with a TaqMan® probe to identify the polA gene. Using PCR, 11 tested positive (64.7%) and 6 (35.3%) were negative. With qPCR and TaqMan® probe, 100% of samples tested positive. The minimum number of spirochetes detected in each sample was 2. With this work, we can conclude that qPCR is a fast and very accurate method for diagnosis of syphilis in tissue specimens.

A retrospective cross-sectional quantitative molecular approach in biological samples from patients with syphilis

Syphilis is the sexually transmitted disease caused by Treponema pallidum, a pathogen highly adapted to the human host. As a multistage disease, syphilis presents distinct clinical manifestations that pose different implications for diagnosis. Nevertheless, the inherent factors leading to diverse disease progressions are still unknown. We aimed to assess the association between treponemal loads and dissimilar disease outcomes, to better understand syphilis. We retrospectively analyzed 309 DNA samples distinct anatomic sites associated with particular syphilis manifestations. All samples had previously tested positive by a PCR-based diagnostic kit. An absolute quantitative real-time PCR procedure was used to precisely quantify the number of treponemal and human cells to determine T. pallidum loads in each sample. In general, lesion exudates presented the highest T. pallidum loads in contrast with blood-derived samples. Within the latter, a higher dispersion of T. pallidum quantities was observed for secondary syphilis. T. pallidum was detected in substantial amounts in 37 samples of seronegative individuals and in 13 cases considered as syphilis-treated. No association was found between treponemal loads and serological results or HIV status. This study suggests a scenario where syphilis may be characterized by: i) heterogeneous and high treponemal loads in primary syphilis, regardless of the anatomic site, reflecting dissimilar duration of chancres development and resolution; ii) high dispersion of bacterial concentrations in secondary syphilis, potentially suggesting replication capability of T. pallidum while in the bloodstream; and iii) bacterial evasiveness, either to the host immune system or antibiotic treatment, while remaining hidden in privileged niches. This work highlights the importance of using molecular approaches to study uncultivable human pathogens, such as T. pallidum, in the infection process.

Detection of Treponema pallidum Sp. Pallidum DNA in Cerebrospinal Fluid (CSF) by Two PCR Techniques

BACKGROUND

Laboratory diagnosis of neurosyphilis is complicated especially when it is asymptomatic, no single laboratory test result being appropriate to diagnose central nervous system infectivity caused by Treponema pallidum. Our objective was to evaluate two polymerase chain reaction (PCR) techniques for the detection of T. pallidum DNA in the cerebrospinal fluid (CSF) of patients with syphilis.

METHODS

One hundred twenty-four CSF samples from patients with reactive blood tests for syphilis were obtained. Two PCR techniques (47-PCR, polA-PCR) were used to detect T. pallidum DNA. The laboratory criteria used for the diagnosis of neurosyphilis to which the PCR techniques were compared were those recommended by the IUSTI: 2008 European guidelines on the management of syphilis.

RESULTS

Treponema pallidum DNA was detected amplified in 37 of 124 (29.8%) and 30 of 124 (24.2%) samples with the 47-PCR and polA-PCR, respectively. Sensitivities were 75.8% and 69.7% and specificities 86.8% and 92.3%, respectively, for 47-PCR and polA-PCR techniques, respectively. The three CSF samples of patients with primary syphilis did not fulfill the criteria of neurosyphilis and DNA was only detected in one by the 47-PCR. In samples from secondary syphilis and neurosyphilis, three of nine and nine of nine respectively, results were coincident for the two PCR techniques and neurosyphilis criteria. Major discrepancies between the two PCR techniques and neurosyphilis diagnostic criteria were observed in latent syphilis.

CONCLUSION

Beyond some limitations of the study, which are discussed here, both PCR techniques seem to be useful for the diagnosis of neurosyphilis, although 47-PCR presents a higher sensitivity and polA-PCR a higher specificity.

UK national guidelines on the management of syphilis 2015

These guidelines are an update for 2015 of the 2008 UK guidelines for the management of syphilis. The writing group have piloted the new BASHH guideline methodology, notably using the GRADE system for assessing evidence and making recommendations. We have made significant changes to the recommendations for screening infants born to mothers with positive syphilis serology and to facilitate accurate and timely communication between the teams caring for mother and baby we have developed a birth plan. Procaine penicillin is now an alternative, not preferred treatment, for all stages of syphilis except neurosyphilis, but the length of treatment for this is shortened. Other changes are summarised at the start of the guideline.

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.

Comparison of Diagnostic Accuracy of PCR Targeting the 47-Kilodalton Protein Membrane Gene of Treponema pallidum and PCR Targeting the DNA Polymerase I Gene: Systematic Review and Meta-analysis

Treponema pallidum PCR (Tp-PCR) testing now is recommended as a valid tool for the diagnosis of primary or secondary syphilis. The objectives were to systematically review and determine the optimal specific target gene to be used for Tp-PCR. Comparisons of the performance of the two main targets are tpp47 and polA genes were done using meta-analysis. Three electronic bibliographic databases, representing abstract books from five conferences specialized in infectious diseases from January 1990 to March 2015, were searched. Search keywords included ("syphilis" OR "Treponema pallidum" OR "neurosyphilis") AND ("PCR" OR "PCR" OR "molecular amplification"). We included diagnostic studies assessing the performance of Tp-PCR targeting tpp47 (tpp47-Tp-PCR) or the polA gene (polA-Tp-PCR) in ulcers from early syphilis. All studies were assessed against quality criteria using the QUADAS-2 tool. Of 37 studies identified, 62.2% were judged at low risk of bias or applicability. Most used the U.S. Centers for Disease Control and Prevention (CDC) case definitions for primary or secondary (early) syphilis (89.2%; n = 33); 15 (40.5%) used darkfield microscopy (DFM). We did not find differences in sensitivity and specificity between the two Tp-PCR methods in the subgroup of studies using adequate reference tests. Among studies using DFM as the reference test, sensitivities were 79.8% (95% confidence intervals [CI], 72.7 to 85.4%) and 71.4% (46.0 to 88.0%) for tpp47-Tp-PCR and polA-Tp-PCR (P = 0.217), respectively; respective specificities were 95.3% (93.5 to 96.6%) and 93.7% (91.8 to 95.2%) (P = 0.304). Our findings suggest that the two Tp-PCR methods have similar accuracy and could be used interchangeably.

Validation of serological tests for the detection of antibodies against Treponema pallidum in nonhuman primates

There is evidence to suggest that the yaws bacterium (Treponema pallidum ssp. pertenue) may exist in non-human primate populations residing in regions where yaws is endemic in humans. Especially in light of the fact that the World Health Organizaiton (WHO) recently launched its second yaws eradication campaign, there is a considerable need for reliable tools to identify treponemal infection in our closest relatives, African monkeys and great apes. It was hypothesized that commercially available serological tests detect simian anti-T. pallidum antibody in serum samples of baboons, with comparable sensitivity and specificity to their results on human sera. Test performances of five different treponemal tests (TTs) and two non-treponemal tests (NTTs) were evaluated using serum samples of 57 naturally T. pallidum-infected olive baboons (Papio anubis) from Lake Manyara National Park in Tanzania. The T. pallidum particle agglutination assay (TP-PA) was used as a gold standard for comparison. In addition, the overall infection status of the animals was used to further validate test performances. For most accurate results, only samples that originated from baboons of known infection status, as verified in a previous study by clinical inspection, PCR and immunohistochemistry, were included. All tests, TTs and NTTs, used in this study were able to reliably detect antibodies against T. pallidum in serum samples of infected baboons. The sensitivity of TTs ranged from 97.7-100%, while specificity was between 88.0-100.0%. The two NTTs detected anti-lipoidal antibodies in serum samples of infected baboons with a sensitivity of 83.3% whereas specificity was 100%. For screening purposes, the TT Espline TP provided the highest sensitivity and specificity and at the same time provided the most suitable format for use in the field. The enzyme immune assay Mastblot TP (IgG), however, could be considered as a confirmatory test.

Pathologic approach to spinal cord infections

The pathologic evaluation of spinal cord infections requires comprehensive clinical, radiological, and laboratory correlation, because the histologic findings in acute, chronic, or granulomatous infections rarely provide clues for the specific cause. This brief review focuses on the pathologic mechanisms as well as practical issues in the diagnosis and reporting of infections of the spinal cord. Examples are provided of the common infectious agents and methods for their diagnosis. By necessity, discussion is restricted to the infections of the medulla spinalis proper and its meninges, and not bone or soft tissue infections.

The endemic treponematoses

The agents of human treponematoses include four closely related members of the genus Treponema: three subspecies of Treponema pallidum plus Treponema carateum. T. pallidum subsp. pallidum causes venereal syphilis, while T. pallidum subsp. pertenue, T. pallidum subsp. endemicum, and T. carateum are the agents of the endemic treponematoses yaws, bejel (or endemic syphilis), and pinta, respectively. All human treponematoses share remarkable similarities in pathogenesis and clinical manifestations, consistent with the high genetic and antigenic relatedness of their etiological agents. Distinctive features have been identified in terms of age of acquisition, most common mode of transmission, and capacity for invasion of the central nervous system and fetus, although the accuracy of these purported differences is debated among investigators and no biological basis for these differences has been identified to date. In 2012, the World Health Organization (WHO) officially set a goal for yaws eradication by 2020. This challenging but potentially feasible endeavor is favored by the adoption of oral azithromycin for mass treatment and the currently focused distribution of yaws and endemic treponematoses and has revived global interest in these fascinating diseases and their causative agents.

Clinical prediction and diagnosis of neurosyphilis in HIV-infected patients with early Syphilis

The diagnosis of neurosyphilis (NS) is a challenge, especially in HIV-infected patients, and the criteria for deciding when to perform a lumbar puncture (LP) in HIV-infected patients with syphilis are controversial. We retrospectively reviewed demographic, clinical, and laboratory data from 122 cases of HIV-infected patients with documented early syphilis who underwent an LP to rule out NS, and we evaluated 3 laboratory-developed validated real-time PCR assays, the Treponema pallidum particle agglutination (TPPA) assay, the fluorescent treponemal antibody absorption (FTA-ABS) assay, and the line immunoassay INNO-LIA Syphilis, for the diagnosis of NS from cerebrospinal fluid (CSF) samples of these patients. NS was defined by a reactive CSF-VDRL test result and/or a CSF white blood cell (WBC) count of >20 cells/μl. Thirty of the 122 patients (24.6%) had early NS. Headache, visual symptoms, a CD4 cell count of <500 cells/μl, and viremia, as defined by an HIV-1 RNA count of ≥50 copies/ml, were associated with NS in multivariate analysis (P = <0.001 for each factor). Blood serum rapid plasma reagin (RPR) titers were not associated with early NS (P = 0.575). For the diagnosis of NS, the PCR, FTA-ABS, TPPA, and INNO-LIA assays had sensitivities of 58%, 100%, 68%, and 100%, specificities of 67%, 12%, 49%, and 13%, and negative predictive values of 85%, 100%, 84%, and 100%, respectively. Visual disturbances, headache, uncontrolled HIV-1 viremia, and a CD4 cell count of <500 cells/μl were predictors of NS in HIV-infected patients with early syphilis, while blood serum RPR titers were not; therefore, RPR titers should not be used as the sole criterion for deciding whether to perform an LP in early syphilis. When applied to CSF samples, the INNO-LIA Syphilis assay easily helped rule out NS.

Advances in the diagnosis of endemic treponematoses: yaws, bejel, and pinta

Improved understanding of the differential diagnosis of endemic treponematoses is needed to inform clinical practice and to ensure the best outcome for a new global initiative for the eradication of yaws, bejel, and pinta. Traditionally, the human treponematoses have been differentiated based upon their clinical manifestations and epidemiologic characteristics because the etiologic agents are indistinguishable in the laboratory. Serological tests are still considered standard laboratory methods for the diagnosis of endemic treponematoses and new rapid point-of-care treponemal tests have become available which are extremely useful in low-resource settings. In the past ten years, there has been an increasing effort to apply polymerase chain reaction to treponematoses and whole genome fingerprinting techniques have identified genetic signatures that can differentiate the existing treponemal strains; however, definitive diagnosis is also hampered by widespread unavailability of molecular diagnostics. We review the dilemmas in the diagnosis of endemic treponematoses, and advances in the discovery of new diagnostic tools.

Etiology of genital ulcer disease in a sexually transmitted infection reference center in Manaus, Brazilian Amazon

OBJECTIVES

To determine the etiology and factors associated with genital ulcer disease (GUD) among patients presenting to a sexually transmitted infections clinic in Manaus, Brazil; and to compare a multiplex polymerase chain reaction (M-PCR) assay for the diagnosis of GUD with standard methods.

METHODS

Ulcer swabs were collected and used for Tzanck test and processed in an M-PCR to detect herpes simplex virus (HSV-1/2), Treponema pallidum (T. pallidum), and Haemophilus ducreyi (H. ducreyi). Sera were tested for HIV and syphilis antibodies. Multivariable analysis was used to measure the association between clinical aspects and GUD. M-PCR results were compared with syphilis serology and Tzanck tests.

RESULTS

Overall, 434 GUD samples were evaluated, 84.8% from men. DNA from HSV-2 was detected in 55.3% of GUD samples, T. pallidum in 8.3%, HSV-1 in 3.2%, and 32.5% of GUD specimens were negative for the DNA of all three pathogens. No cases of H. ducreyi were identified. HIV serology among GUD patients was 3.2%. Treponemal antibodies and Tzanck test positivity for genital herpes was detected in 25 (5.8%) and in 125 (30.3%) of GUD patients, respectively. In multivariable analysis genital herpes etiology by M-PCR was associated with the vesicular, multiple and recurrent lesions whereas T. pallidum with non-vesicular, non-recurrent lesions. Compared to M-PCR, syphilis serology was 27.8% sensitive and 96.2% specific whereas Tzanck test was 43.8% sensitive and 88.9% specific.

CONCLUSIONS

The predominance of genital herpes etiology suggests a revision of existing national syndromic treatment guidelines in Brazil to include antiherpetic treatment for all GUD patients. The use of M-PCR can significantly improve the diagnosis of GUD and provide a greater sensitivity than standard diagnostics.

Genital ulcer disease in India: etiologies and performance of current syndrome guidelines

BACKGROUND

In India, genital ulcer disease (GUD) syndrome is clinically classified as herpetic or nonherpetic and managed accordingly; laboratory support is unavailable at most health facilities. We undertook a study to determine the etiology of GUDs in men presenting to sexually transmitted infection (STI) clinics and assess the performance of the national algorithm for syndromic management of herpetic and nonherpetic GUDs in India.

METHOD

A cross-sectional study was conducted among men with complaints of genital ulcers attending 8 STI clinics in 4 states. Ulcer swabs were collected and tested by the multiplex polymerase chain reaction method to determine the etiology of GUD.

RESULTS

Of the 194 men recruited, etiology was confirmed in 121 GUD cases (62%). Herpes simplex virus (48%) was the most common etiological agent identified, followed by Treponema pallidum (23%) and mixed infections (9%). One case of Haemophilus ducreyi was confirmed in this series. The overall sensitivity and specificity of the national syndromic management algorithm for GUD were 68% and 52%, respectively. Using the national algorithm, 52 (42%) cases clinically misclassified as either herpetic (18 cases) or nonherpetic (34 cases) GUD resulting in incorrect treatment.

CONCLUSIONS

Our findings suggest a revision of existing national STI treatment guidelines in India to include treatment of syphilis infections of all GUD patients. Periodic studies are required to monitor changing spectrum of GUD etiologies in India.

A longitudinal evaluation of Treponema pallidum PCR testing in early syphilis

Background

Syphilis is a growing public health problem among men who have sex with men (MSM) globally. Rapid and accurate detection of syphilis is vital to ensure patients and their contacts receive timely treatment and reduce ongoing transmission.

Methods

We evaluated a PCR assay for the diagnosis of Treponema pallidum using swabs of suspected early syphilis lesions in longitudinally assessed MSM.

Results

We tested 260 MSM for T pallidum by PCR on 288 occasions: 77 (26.7%) had early syphilis that was serologically confirmed at baseline or within six weeks, and 211 (73.3%) remained seronegative for syphilis. Of 55 men with primary syphilis, 49 were PCR positive, giving a sensitivity of 89.1% (95% CI: 77.8%-95.9%) and a specificity of 99.1% (95% CI: 96.5%-99.9%). Of 22 men with secondary syphilis, 11 were PCR positive, giving a sensitivity of 50% (95% CI: 28.2%-71.8%) and a specificity of 100% (95% CI: 66.4%-71.8%). Of the 77 syphilis cases, 43 (56%) were HIV positive and the sensitivity and specificity of the PCR test did not vary by HIV status. The PCR test was able to detect up to five (10%) primary infections that were initially seronegative, including one HIV positive man with delayed seroconversion to syphilis (72 to 140 days) and one HIV positive man who did not seroconvert to syphilis over 14 months follow-up. Both men had been treated for syphilis within a week of the PCR test.

Conclusions

T pallidum PCR is a potentially powerful tool for the early diagnosis of primary syphilis, particularly where a serological response has yet to develop.

Molecular subtyping of Treponema pallidum during a local syphilis epidemic in men who have sex with men in Melbourne, Australia

Treponema pallidum is the causative agent of syphilis, a sexually transmitted infection of significant public health importance. Since 2000 there has been a marked increase in the number of cases of syphilis infections notified in Victoria, Australia, with the majority of cases occurring in men who have sex with men (MSM) and the highest incidence being in HIV-infected MSM. The molecular subtyping method described by Pillay et al. (A. Pillay et al., Sex. Transm. Dis. 25:408-414, 1998) has been used in this study to determine the diversity of T. pallidum subtypes circulating locally and to look for any relationship between T. pallidum subtypes and HIV status over a 6-year period (2004 to 2009). Treponema pallidum DNA was detected in 303 patient specimens (n = 3,652), and full subtyping profiles were obtained from 90 of these (from 88 patients). A total of 11 T. pallidum subtypes were identified: types 14e (28, 31.1%), 14d (15, 16.7%), 14k (13, 14.4%), 14p (12, 13.3%), 14i (7, 7.8%) 14b (6, 6.7%), 14l (5, 5.6%), and 12i, 13b, 13i, and 13e (1 each, 1.1%). This study showed a similar level of variation among circulating T. pallidum strains compared with that in other studies using the same methodology. A different mix of strains and different predominating strains have been found at each geographical study location, with type 14e emerging as the predominant local strain in Victoria. There was no detectable trend between T. pallidum subtypes and the specimen collection site or stage of syphilis (where known), nor was there any relationship between particular strains and HIV status.

Detection of the Treponema pallidum gene and variation of treponemal DNA load before and after therapy

We explored a genetic detection method for Treponema pallidum (TP) in the peripheral blood of infected patients to compare the loads of treponemal DNA before and after therapy and to see if this new technique enabled assessment of therapeutic effect and detection of serum resistance. Polymerase chain reaction was used for a qualitative detection of TP DNA in peripheral blood and then a semiquantitative method was adopted to estimate the load of TP DNA in blood, both before and after treatment of syphilis. Among 30 untreated patients, three cases were TP DNA-positive. Among 42 treated patients with demonstrated serum resistance, three cases were TP DNA-positive. Five cases in which the rapid plasma reagin had become negative had no detectable TP DNA in their peripheral blood. The TP DNA load in blood after treatment was significantly lower than that before therapy. We conclude that the detection of TP DNA in peripheral blood of TP-infected patients is not yet sufficiently sensitive, but we observed that TP DNA load declines significantly after treatment.

Evaluation of a PCR test for detection of treponema pallidum in swabs and blood

Syphilis diagnosis is based on clinical observation, serological analysis, and dark-field microscopy (DFM) detection of Treponema pallidum subsp. pallidum, the etiological agent of syphilis, in skin ulcers. We performed a nested PCR (nPCR) assay specifically amplifying the tpp47 gene of T. pallidum from swab and blood specimens. We studied a cohort of 294 patients with suspected syphilis and 35 healthy volunteers. Eighty-seven of the 294 patients had primary syphilis, 103 had secondary syphilis, 40 had latent syphilis, and 64 were found not to have syphilis. The T. pallidum nPCR results for swab specimens were highly concordant with syphilis diagnosis, with a sensitivity of 82% and a specificity of 95%. Reasonable agreement was observed between the results obtained with the nPCR and DFM methods (kappa = 0.53). No agreement was found between the nPCR detection of T. pallidum in blood and the diagnosis of syphilis, with sensitivities of 29, 18, 14.7, and 24% and specificities of 96, 92, 93, and 97% for peripheral blood mononuclear cell (PBMC), plasma, serum, and whole-blood fractions, respectively. HIV status did not affect the frequency of T. pallidum detection in any of the specimens tested. Swab specimens from mucosal or skin lesions seemed to be more useful than blood for the efficient detection of the T. pallidum genome and, thus, for the diagnosis of syphilis.