Laboratory diagnosis and interpretation of tests for syphilis

Prioritizing congenital syphilis control in south China: a decision analytic model to inform policy implementation

BACKGROUND

Syphilis is a major public health problem in many regions of China, with increases in congenital syphilis (CS) cases causing concern. The Chinese Ministry of Health recently announced a comprehensive 10-y national syphilis control plan focusing on averting CS. The decision analytic model presented here quantifies the impact of the planned strategies to determine whether they are likely to meet the goals laid out in the control plan.

METHODS AND FINDINGS

Our model incorporated data on age-stratified fertility, female adult syphilis cases, and empirical syphilis transmission rates to estimate the number of CS cases associated with prenatal syphilis infection on a yearly basis. Guangdong Province was the focus of this analysis because of the availability of high-quality demographic and public health data. Each model outcome was simulated 1,000 times to incorporate uncertainty in model inputs. The model was validated using data from a CS intervention program among 477,656 women in China. Sensitivity analyses were performed to identify which variables are likely to be most influential in achieving Chinese and international policy goals. Increasing prenatal screening coverage was the single most effective strategy for reducing CS cases. An incremental increase in prenatal screening from the base case of 57% coverage to 95% coverage was associated with 106 (95% CI: 101, 111) CS cases averted per 100,000 live births (58% decrease). The policy strategies laid out in the national plan led to an outcome that fell short of the target, while a four-pronged comprehensive syphilis control strategy consisting of increased prenatal screening coverage, increased treatment completion, earlier prenatal screening, and improved syphilis test characteristics was associated with 157 (95% CI: 154, 160) CS cases averted per 100,000 live births (85% decrease).

CONCLUSIONS

The Chinese national plan provides a strong foundation for syphilis control, but more comprehensive measures that include earlier and more extensive screening are necessary for reaching policy goals.

Selecting and Screening Donors

Oocyte donation was originally established in 1983 as a treatment option for younger women with premature ovarian failure and for women with severe pelvic disease whose ovaries, as a result, were surgically inaccessible. The indications for donor oocyte in vitro fertilization (IVF) have now expanded to include not only women with hypergonadotropic hypogonadism but also those with advanced reproductive age, diminished ovarian reserve, significant genetic disease risk, poor oocyte or embryo quality, or multiple failures in prior attempts to conceive using conventional assisted reproductive technology (ART). Oocyte donation has also been recently used as an important source of material to promote the study of stem cell research.

In these first cases of donation, gametes were obtained primarily from women already undergoing IVF who had excess oocytes at the time of retrieval. Today, most egg donors are not currently pursing infertility treatment themselves but are willing to donate their gametes for altruistic or commercial reasons. Since its initiation, oocyte donation services have spread throughout the USA and to many areas of the world. In the USA, 9,000–10,000 donor oocyte cycles occur annually. Though donor oocyte IVF is available throughout the USA, globally the practice of oocyte donation varies due to legal restrictions in many countries (Chap. 30).

Prevalence of serological markers and risk factors for bloodborne pathogens in Salvador, Bahia state, Brazil

This study aimed to determine the prevalence of serological markers for HIV-1/2, HBV, HCV, Treponema cruzi and T. pallidum infections. The association of these infections with risk factors in a population from Salvador, Bahia, Brazil was also analysed. Of the 780 enrolled individuals, 545 (70%) were female and 235 (30%) were male. Seroprevalence of 0·8% (6/702), 1·3% (9/678), 1·5% (10/684), 3·5% (23/663) and 11·5% (77/668) for HIV-1/2, HBV, HCV, T. cruzi and T. pallidum infections, respectively, was observed. The seroprevalence of T. pallidum was higher in males 20% (43/210) than in females 7% (34/458) (P < 0·01). An association between age and seroprevalence for T. cruzi (P = 0·02) and T. pallidum (P < 0·01) was observed. HBsAg was associated with having tattoos (3/37 vs. 6/623, P = 0·01) and not having a steady sexual partner (5/141 vs. 4/473, P = 0·04), while anti-HIV-1/2 was associated with having tattoos (2/39 vs. 4/647, P = 0·04); however, larger studies are needed to categorically state the relationship of these risk factors with infectious agents. The prevalence of serological markers for HIV-1/2, HBV, HCV and T. cruzi was consistent with other studies.

Characterization of sera with discordant results from reverse sequence screening for syphilis

Reverse sequence screening for syphilis (RSSS) (screening with treponemal tests, followed by confirmation with nontreponemal tests) has been increasingly adopted. CDC recommends confirmation of discordant results (reactive EIA/CIA and nonreactive nontreponemal test) with Treponema pallidum particle agglutination assay (TP-PA). We characterized sera with discordant results from RSSS with Architect Syphilis TP CIA. Among 15,713 screening tests using Architect Syphilis TP at Seoul National University Gangnam Center between October 2010 and May 2011, 260 (1.7%) showed reactive results. Rapid plasma reagin (RPR) and TP-PA were performed on 153 available sera among them. On sera with discordant results between Architect Syphilis TP and TP-PA, INNO-LIA Syphilis Score and FTA-ABS were performed. Among 153 sera, RPR was nonreactive in 126 (82.4%). Among them, TP-PA was positive in 103 (81.7%), indeterminate (±) in 7 (5.6%), and negative in 16 (12.7%). Out of 16 CIA(+)/RPR(-)/TP-PA(-) sera, INNO-LIA Syphilis Score and/or FTA-ABS were negative on 14 sera. Out of 7 CIA(+)/RPR(-)/TP-PA(±) sera, INNO-LIA Syphilis Score and FTA-ABS were positive/reactive in 6 sera. RSSS with confirmation by TP-PA on sera with discordant results between Architect Syphilis TP and RPR effectively delineated those discordant results and could be successfully adopted for routine checkup for syphilis.

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.

Work quality in serological laboratories dealing with syphilis diagnostics in specialized medical institutions of the dermatovenerology profile in the Russian Federation

The authors present the results of the analysis of a questionnaire survey held in laboratories in 83 specialized medical institutions of the dermatovenerology profile in the Russian Federation and assess the work quality of serological laboratories dealing with syphilis diagnostics. They determined positive and negative aspects of the laboratory diagnostics of syphilis as well as basic indices of the work quality in serological laboratories dealing with syphilis diagnostics.

A dual point-of-care test shows good performance in simultaneously detecting nontreponemal and treponemal antibodies in patients with syphilis: a multisite evaluation study in China

BACKGROUND

Rapid point-of-care (POC) syphilis tests based on simultaneous detection of treponemal and nontreponemal antibodies (dual POC tests) offer the opportunity to increase coverage of syphilis screening and treatment. This study aimed to conduct a multisite performance evaluation of a dual POC syphilis test in China.

METHODS

Participants were recruited from patients at sexually transmitted infection clinics and high-risk groups in outreach settings in 6 sites in China. Three kinds of specimens (whole blood [WB], fingerprick blood [FB], and blood plasma [BP]) were used for evaluating sensitivity and specificity of the Dual Path Platform (DPP) Syphilis Screen and Confirm test using its treponemal and nontreponemal lines to compare Treponema pallidum particle agglutination (TPPA) assay and toluidine red unheated serum test (TRUST) as reference standards.

RESULTS

A total of 3134 specimens (WB 1323, FB 488, and BP 1323) from 1323 individuals were collected. The sensitivities as compared with TPPA were 96.7% for WB, 96.4% for FB, and 94.6% for BP, and the specificities were 99.3%, 99.1%, and 99.6%, respectively. The sensitivities as compared with TRUST were 87.2% for WB, 85.8% for FB, and 88.4% for BP, and the specificities were 94.4%, 96.1%, and 95.0%, respectively. For specimens with a TRUST titer of 1:4 or higher, the sensitivities were 100.0% for WB, 97.8% for FB, and 99.6% for BP.

CONCLUSIONS

 DPP test shows good sensitivity and specificity in detecting treponemal and nontreponemal antibodies in 3 kinds of specimens. It is hoped that this assay can be considered as an alternative in the diagnosis of syphilis, particularly in resource-limited areas.

New proteins for a new perspective on syphilis diagnosis

Syphilis is a sexually transmitted disease caused by Treponema pallidum subsp. pallidum; it can be effectively treated with penicillin yet remains prevalent worldwide, due in part to the shortcomings of current diagnostic tests. Here we report the production of soluble recombinant versions of three novel diagnostic candidate proteins, Tp0326, Tp0453, and a Tp0453-Tp0326 chimera. The sensitivities of these recombinant proteins were assessed by screening characterized serum samples from primary, secondary, and latent stages of infection (n = 169). The specificities were assessed by screening false positives identified with the standard diagnostic testing algorithm (n = 21), samples from patients with potentially cross-reactive infections (Leptospira spp., Borrelia burgdorferi, Helicobacter pylori, Epstein-Barr virus, hepatitis B virus, hepatitis C virus, or cytomegalovirus) (n = 38), and samples from uninfected individuals (n = 11). The sensitivities of Tp0326, Tp0453, and the Tp0453-Tp0326 chimera were found to be 86%, 98%, and 98%, respectively, and the specificities were 99%, 100%, and 99%. In a direct comparison, the Captia syphilis (T. pallidum)-G enzyme immunoassay (Trinity Biotech) was used to screen the same serum samples and was found to have a sensitivity of 98% and a specificity of 90%. In particular, Tp0453 and the chimera exhibited superior accuracy in classifying analytical false-positive samples (100%, compared to 43% for the Captia assay). These findings identify Tp0453 and the Tp0453-Tp0326 chimera as novel syphilis-specific diagnostic candidates that surpass the performance of a currently available diagnostic enzyme immunoassay test for syphilis and that allow accurate detection of all stages of infection.

Comparative study of Treponemal and non-Treponemal test for screening of blood donated at a blood center

The non-Treponemal tests such as Rapid Plasma Reagin test (RPR) or the Venereal Disease Reference Laboratory test are the most commonly used test for screening of syphilis in the blood centers in India. Now, with the availability of Enzyme-linked immunosorbent assay (ELISA) and Immunochromatographic assays in the market, we decided to evaluate these assays in comparison with Treponema pallidum Haemagglutination Assay (TPHA) which was considered as a gold standard for this study. A total of 8 685 samples of voluntary blood donors were tested on Trepolisa 3.0 and then the initially reactive samples were retested in duplicate on the same assay as well as on Omega Pathozyme, RPR, RAPHA (Rapid Anti-Treponema pallidum Assay), and TPHA. Of the 158 initially reactive samples, 104 were repeatedly reactive on the same assay, 85 were reactive with RPR, 77 were reactive with RAPHA, 60 were reactive on Omega, and 53 were confirmed reactive on TPHA. 48 (56.4%) of the results on RPR were biological false positive, while 21.9% of results were false negative on RPR. We evaluated that Omega Pathozyme was quite in agreement with TPHA as compared with Trepolisa 3.0, RAPHA, and RPR. We concluded that Omega Pathozyme (ELISA) can be considered as a suitable test for screening of syphilis in a blood center.

Impact of reverse sequence syphilis screening on new diagnoses of late latent syphilis in Edmonton, Canada

After the introduction of reverse sequence syphilis screening in Alberta, Canada, there was an increase in the diagnosis of late latent syphilis in individuals screening positive with the treponemal test; these cases required additional public health follow-up.

Serological response to treatment of syphilis according to disease stage and HIV status

The serological response to treatment was studied in 264 syphilis patients; it was influenced by syphilis stage but not by human immunodeficiency virus infection and reinfection. Some of the recommendations of current guidelines are critically discussed, and amendments are proposed.

Background. Serology is the mainstay for syphilis diagnosis and treatment monitoring. We investigated serological response to treatment of syphilis according to disease stage and HIV status.

Methods. A retrospective cohort study of 264 patients with syphilis was conducted, including 90 primary, 133 secondary, 33 latent, and 8 tertiary syphilis cases. Response to treatment as measured by the Venereal Disease Research Laboratory (VDRL) test and a specific IgM (immunoglobulin M) capture enzyme-linked immunosorbent assay (ELISA; Pathozyme-IgM) was assessed by Cox regression analysis.

Results. Forty-two percent of primary syphilis patients had a negative VDRL test at their diagnosis. Three months after treatment, 85%–100% of primary syphilis patients had reached the VDRL endpoint, compared with 76%–89% of patients with secondary syphilis and 44%–79% with latent syphilis. In the overall multivariate Cox regression analysis, serological response to treatment was not influenced by human immunodeficiency virus (HIV) infection and reinfection. However, within primary syphilis, HIV patients with a CD4 count of <500 cells/μL had a slower treatment response (P = .012). Compared with primary syphilis, secondary and latent syphilis showed a slower serological response of VDRL (P = .092 and P < .001) and Pathozyme-IgM tests (P < .001 and P = .012).

Conclusions. The VDRL should not be recommended as a screening test owing to lack of sensitivity. The syphilis disease stage significantly influences treatment response whereas HIV coinfection only within primary syphilis has an impact. VDRL test titers should decline at least 4-fold within 3–6 months after therapy for primary or secondary syphilis, and within 12–24 months for latent syphilis. IgM ELISA might be a supplement for diagnosis and treatment monitoring.

The rapid plasma reagin test cannot replace the venereal disease research laboratory test for neurosyphilis diagnosis

BACKGROUND

The cerebrospinal fluid (CSF) Venereal Disease Research Laboratory (VDRL) test is a mainstay for neurosyphilis diagnosis, but it lacks diagnostic sensitivity and is logistically complicated. The rapid plasma reagin (RPR) test is easier to perform, but its appropriateness for use on CSF is controversial.

METHODS

RPR reactivity was determined for CSF from 149 individuals with syphilis using 2 methods. The CSF-RPR was performed according to the method for serum. The CSF-RPR-V was performed using the method recommended for the CSF-VDRL. Laboratory-defined neurosyphilis included reactive CSF-fluorescent treponemal antibody absorption test and CSF white blood cells >20/uL. Symptomatic neurosyphilis was defined as vision loss or hearing loss.

RESULTS

CSF-VDRL was reactive in 45 (30.2%) patients. Of these, 29 (64.4%) were CSF-RPR reactive and 37 (82.2%) were CSF-RPR-V reactive. There were no instances where the CSF-VDRL was nonreactive but the CSF-RPR or CSF-RPR-V was reactive. Among the 28 samples that were reactive in all 3 tests, CSF-VDRL titers (median [IQR], 1:4 [1:4-1:16]) were significantly higher than CSF-RPR (1:2 [1:1-1:4], P = 0.0002) and CSF-RPR-V titers (1:4 [1:2-1:8], P = 0.01). The CSF RPR and the CSF-RPR-V tests had lower sensitivities than the CSF-VDRL: 56.4% and 59.0% versus 71.8% for laboratory-diagnosed neurosyphilis and 51.5% and 57.6% versus 66.7% for symptomatic neurosyphilis.

CONCLUSIONS

Compared with the CSF-VDRL, the CSF-RPR has a high false-negative rate, thus not improving upon this known limitation of the CSF-VDRL for neurosyphilis diagnosis. Adapting the RPR procedure to mimic the CSF-VDRL decreased, but did not eliminate, the number of false negatives and did not avoid all the logistical complications of the CSF-VDRL.

Significance of isolated reactive treponemal chemiluminescence immunoassay results

BACKGROUND

Isolated reactive serum treponemal chemiluminescence immunoassay (CIA) specimens cause clinical uncertainty.

METHODS

Sera were screened by CIA, and reactive samples underwent reflex testing with rapid plasma reagin (RPR), Treponema pallidum particle agglutination (TPPA), and fluorescent treponemal antibody absorption (FTA Abs) assays. Samples reactive only on the CIA were deemed "isolated" reactive CIA samples. We undertook detailed review of a subset of subjects with isolated reactive CIA specimens.

RESULTS

Of 28 261 specimens, 1171 (4.1%) were reactive on CIA, of which 133 (11.3%) had isolated CIA reactivity. Most subjects (66 of 82 [80.5%]) with isolated reactive CIA specimens were from high-prevalence populations. We found evidence of CIA, TPPA, and FTA Abs seroreversion. The median chemiluminescent signal-to-cutoff ratio was similar for isolated reactive CIA sera and sera that were reactive on either FTA Abs or TPPA assays (2.19 vs 2.32; P = .15) but lower than for sera reactive on both FTA Abs and TPPA assays (12.37; P < .001) or for sera reactive on RPR assays (25.53; P < .001). A total of 11 of 20 patients (55%) with an isolated reactive CIA specimen who underwent medical record review had previous or subsequent evidence of syphilis infection.

CONCLUSIONS

Isolated reactive CIA specimens may represent true T. pallidum infection and may be found after seroreversion of traditional treponemal assays.

Luetic lymphadenopathy despite negative serology

Laboratory tests can be misleading for the diagnosis of syphilis and false-negative results are possible, but it is rare for both treponemal and non-treponemal tests to prove negative in different stages of the disease. We report on a case of luetic lymphadenopathy, diagnosed by histological examination and supported by immunohistochemical staining for Treponema pallidum, in the absence of skin lesions and positive serology. This case reminds us of how syphilis may present in many different clinical forms and that it should not be excluded only on the basis of negative serological tests. This patient's negative serology was probably due to inadequate initial antibiotic therapy. Given the current widespread use of antibiotics, greater consideration is warranted of the extent to which serological test results are modified by non-specific antibiotic therapies.

Syphilis Infection during pregnancy: fetal risks and clinical management

Congenital syphilis is still a cause of perinatal morbidity and mortality. Untreated maternal infection leads to adverse pregnancy outcomes, including early fetal loss, stillbirth, prematurity, low birth weight, neonatal and infant death, and congenital disease among newborns. Clinical manifestations of congenital syphilis are influenced by gestational age, stage of maternal syphilis, maternal treatment, and immunological response of the fetus. It has been traditionally classified in early congenital syphilis and late congenital syphilis. Diagnosis of maternal infection is based on clinical findings, serological tests, and direct identification of treponemes in clinical specimens. Adequate treatment of maternal infection is effective for preventing maternal transmission to the fetus and for treating fetal infection. Prenatal diagnosis of congenital syphilis includes noninvasive and invasive diagnosis. Serological screening during pregnancy and during preconception period should be performed to reduce the incidence of congenital syphilis.

Syphilis d' emblee

A 28-year-old male patient presented to Skin, V.D. and Leprosy outpatient with a single gray white plaque on the left side of the lower lip for last 8 months and multiple papulosquamous lesions all over the body for last 6 months. There was history of blood transfusion for anemia 1 year back. Histopathology of lip lesion and reactive VDRL and TPHA tests confirmed the diagnosis as syphilis. We report this rare case of Syphilis d' emblee.

The importance of IgM positivity in laboratory diagnosis of gestational and congenital syphilis

From January 1, 2009 through December 31, 2011, from 33,753 blood samples for syphilis screening, Treponema pallidum infections were confirmed in 241 pregnant women at the Department of Dermatology, Venerology, and Dermatooncology of Semmelweis University Budapest. In this period, four children born to inadequately or untreated women were confirmed to have connatal syphilis. The height of rapid plasma reagin (RPR) titer was measured to determine the stage of the infection and to examine the success of the antilues therapy. The diagnosis of maternal syphilis infection was confirmed with enzyme linked immunosorbent assay (ELISA), T. pallidum particle agglutination (TPPA), and IgG and IgM immunoblots. Maternal IgM immunoblot results identify mothers at risk of delivering babies with connatal syphilis better than the height of maternal RPR titer. The standard serological tests are less useful in newborns because of IgG transfer across the placenta. IgM test which depends on the infant's response has more specificity in diagnosing connatal syphilis.

Prevalence of Treponema pallidum seropositivity and herpes simplex virus type 2 infection in a cohort of men who have sex with men, Bangkok, Thailand, 2006–2010

We report prevalence of Treponema pallidum (TP) seropositivity and herpes simplex virus type 2 (HSV-2) infection and risk factors associated with their prevalence in a cohort of men who have sex with men (MSM) in Bangkok, Thailand. Between April 2006 and March 2010 we enrolled Thai MSM into a cohort study based at the Silom Community Clinic, with baseline behavioural data and laboratory testing for sexually transmitted infections (STIs). Logistic regression was used to analyse risk factors associated with the prevalence of TP seropositivity and HSV-2 infection. From a total of 1544 enrolled men (mean age 26 years) TP, HSV-2 and HIV seropositive rates were 4.4%, 20.7% and 21.6%, respectively. After multivariable analysis, participating in group sex, reporting paying for sex, reporting sex with a casual partner in a park and being HSV-2 seropositive were associated with TP prevalence. Age ≥30 years, having less than a high school education, past use of recreational drugs, meeting casual sexual partners at a public venue (sauna) and TP seropositivity were associated with HSV-2 infection. The significant baseline prevalence of TP seropositivity and HSV-2 infection in this cohort demonstrates the need for screening and treatment of these STIs and targeted prevention interventions in Thai MSM in Bangkok.

Understanding the HIV/AIDS epidemic in transgender women of Lima, Peru: results from a sero-epidemiologic study using respondent driven sampling

In Latin America, transgender women (transwomen or male to female transgenders) have been included in MSM research but without addressing their specific needs in terms of the HIV/AIDS. We present results of the first seroepidemiologic study designed for transwomen in Peru. We conducted a study using respondent driven sampling to recruit transwomen from Lima. Our survey explored sociodemographic characteristics, gender enhancement procedures and sexual behavior. In addition, we conducted laboratory based HIV, genital herpes (HSV2) and syphilis testing. A total of 450 transwomen were recruited between April and July 2009. HIV prevalence was 30%, HSV2: 79% and syphilis: 23%. Sex-work was the main economic activity (64%). Gender enhancement procedures were reported by 70% of the population. Multivariable analysis showed HIV infection to be associated with being older than 35 recent, syphilis infection and HSV2 infection. Transwomen are the group most vulnerable to HIV/AIDS in Peru.

Serum and cerebrospinal fluid profiles for syphilis in Thai patients with acute ischaemic stroke

The diagnosis of neurosyphilis is complicated in elderly patients who have cerebrovascular risk factors and present with ischaemic stroke. We performed an analysis of serum and cerebrospinal fluid (CSF) profiles for neurosyphilis in acute stroke patients, particularly in those with atherosclerotic risk factors. In sera, the rapid plasma reagin (RPR) test and Treponema pallidum haemagglutination assay (TPHA) were used. In CSF, the RPR and fluorescent treponemal antibody-absorption tests were used together with CSF white blood cell (WBC) count and protein level. Baseline characteristics, including atherosclerotic risk factors, severity of stroke and computed tomography brain scan images were collected. Of the total 284 patients, 24 (8.4%) had TPHA-positive sera, from which 29.2% had a positive CSF for syphilis. Seven stroke patients (2.5%), with a mean age of 65.7 years, were diagnosed with symptomatic neurosyphilis, and 71% of them had atherosclerotic risk factors. Most symptomatic patients (85.7%) had CSF WBCs>20 cells/mm3, with a mean of 98.6 ± 136.0 versus 3.2 ± 7.3 in non-neurosyphilitic patients ( P = 0.0009). Less than 50% of the symptomatic patients had CSF protein levels >50 mg/dL, and the protein levels of neurosyphilitic and non-neurosyphilitic groups were not significantly different, with means of 52.0 ± 12.9 and 51.8 ± 15.9 mg/dL, respectively. There were no significant differences in age and stroke severity. Interpretation of CSF findings, particularly of CSF WBC counts and protein levels, must be appropriate to ascertain true symptomatic neurosyphilis cases and to reduce false-positive diagnoses, particularly in countries with a high prevalence of T. pallidum infection.

VDRL test and its interpretation

Venereal disease research laboratory (VDRL) test is a nontreponemal test, used for screening of syphilis due to its simplicity, sensitivity and low cost. Prozone phenomenon and biological false positive (BFP) reaction are two shortcomings of this test. Quantitative estimation of VDRL is essential in treatment evaluation. CSF VDRL test is very specific for neurosyphilis though its sensitivity is low. Interpretation of VDRL in HIV infection is incompletely understood.

Treatment and diagnostic accuracy of neurosyphilis at Boston City Hospital's Neurological Unit, 1930-1979

The twentieth century was marked with frequent advances in the treatment and diagnosis of neurosyphilis. Once considered one of the most serious human diseases, neurosyphilis was paramount to a death sentence often preceded by agonizing pain and/or diminishing mental capacities. Since the introduction of penicillin in 1943, however, the prevalence of neurosyphilis has declined dramatically and the prognosis of the few still affected has been greatly improved. We examined patient records from Boston City Hospital's (BCH) Neurologic Unit from 1930 to 1979 to obtain primary data on treatment modalities for neurosyphilis during this period, with particular attention to the use of malarial therapy. We also evaluated these same records to determine whether the "great imitator" moniker that was applied to neurosyphilis may have in part been due to systematic errors in diagnostic criteria and false positive tests. The BCH neurologists used all available treatment compounds, including arsenicals, bismuth, iodides, malaria, and typhoid. The data also suggest that the wide diversity of symptoms attributed to neurosyphilis was probably accurate.

Which algorithm should be used to screen for syphilis?

PURPOSE OF REVIEW

A growing number of laboratories have implemented a reverse screening algorithm for syphilis testing, which has created confusion among many healthcare providers. This review focuses on recent data addressing the clinical and economical impact of reverse screening and discusses the advantages and limitations of the traditional and contemporary algorithms.

RECENT FINDINGS

Screening for syphilis using a treponemal assay detects a higher number of patients with reactive results compared to traditional screening by rapid plasma reagin (RPR). Furthermore, a significant percentage of patients who are reactive by a treponemal screening assay are nonreactive by RPR. These discordant results may occur in patients with past, treated or untreated syphilis; early syphilis; or no syphilis. Recent reports suggest that the reverse screening algorithm may result in increased patient follow-ups, overtreatment, and potentially higher cost. However, other data suggest that reverse screening facilitates the detection of latent and early syphilis, while offering an objective and automated screening approach.

SUMMARY

The Centers for Disease Control and Prevention currently recommends syphilis screening with a nontreponemal test. However, as laboratories continue to implement the reverse screening algorithm, it is important that samples with discordant screen-reactive, RPR-nonreactive results be tested by a second treponemal assay to assist in the interpretation of results.

Evaluation of an IgM/IgG sensitive enzyme immunoassay and the utility of index values for the screening of syphilis infection in a high-risk population

BACKGROUND

Increasing interest in the use of enzyme immunoassays (EIA) for syphilis screening has generated a considerable need for data on the performance of such tests.

METHODS

We compared the performance of 1 EIA, the TREP-SURE EIA to that of the Venereal Disease Research Laboratory (VDRL) and Treponema pallidum particle agglutination assay (TPPA) in the detection of infection with Treponema pallidum. In total, 674 specimens were tested by VDRL and EIA (356 VDRL-nonreactive and 318 VDRL-reactive). All specimens that were found to be reactive by either the VDRL or EIA were subsequently analyzed by TPPA.

RESULTS

We found that the TREP-SURE EIA was marginally less sensitive than the VDRL test for screening, but was significantly more specific. All EIA-TPPA discordant specimens were analyzed by multiple tests, including Immunoglobulin M- and G-specific Western blots and an IgM-specific EIA. Signal-to-cutoff ratios (index values) generated by the TREP-SURE EIA were also investigated. It was found that these values may be instructive regarding the interpretation of test results, as they were found to correlate strongly with the probability of positivity on a TPPA assay. Specimens that reacted positively on the EIA with very high index values were found overwhelmingly to be reactive by TPPA, perhaps obviating the need for the testing of most EIA positive specimens with a secondary treponemal test.

CONCLUSIONS

An IgM/IgG sensitive EIA would be an effective alternative to VDRL for syphilis screening. Using the EIA index values may provide additional, helpful information to the diagnostic process.

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.

Protocols for detection and typing of Treponema pallidum using PCR methods

Syphilis, caused by Treponema pallidum, is a sexually transmitted disease which was epidemic in Europe between the 15th and 20th century. From 2000 onwards it is worldwide mostly encountered among men who have sex with men but also among women in resource poor setting. Syphilis can easily be treated with penicillin but can become chronic, if left untreated. The disease develops in several stages with ulcerative lesions in the primary stage, and systemic spread to organs via the blood in later stages. Taking swab samples from these ulcerative lesions gives the best options for detection by PCR of T. palillidum. Alternatively blood samples can be analyzed in later stages. If tested positive in screening PCR assays, T. pallidum can also be typed by molecular methods, enabling molecular epidemiology. Different protocols are discussed in this chapter, that include all steps from sample collection, nucleic acid extraction, PCR, and detection. The combination of all steps together determine the final sensitivity and specificity of T. pallidum PCR.

Evaluating frequency, diagnostic quality, and cost of Lyme borreliosis testing in Germany: a retrospective model analysis

Background. Data on the economic impact of Lyme borreliosis (LB) on European health care systems is scarce. This project focused on the epidemiology and costs for laboratory testing in LB patients in Germany. Materials and Methods. We performed a sentinel analysis of epidemiological and medicoeconomic data for 2007 and 2008. Data was provided by a German statutory health insurance (DAK) company covering approx. 6.04 million members. In addition, the quality of diagnostic testing for LB in Germany was studied. Results. In 2007 and 2008, the incident diagnosis LB was coded on average for 15,742 out of 6.04 million insured members (0.26%). 20,986 EIAs and 12,558 immunoblots were ordered annually for these patients. For all insured members in the outpatient sector, a total of 174,820 EIAs and 52,280 immunoblots were reimbursed annually to health care providers (cost: 2,600,850€). For Germany, the overall expected cost is estimated at 51,215,105€. However, proficiency testing data questioned test quality and standardization of diagnostic assays used. Conclusion. Findings from this study suggest ongoing issues related to care for LB and may help to improve future LB disease management.

Clinical aspects of congenital syphilis with Hutchinson's triad

Congenital syphilis is an infectious disease caused by Treponema pallidum transmitted by infected mother to her baby during pregnancy. Late congenital syphilis is recognised with 2 or more years after birth. One of the main aspects is observed with the triad of Hutchinson, characterised by the presence of interstitial keratitis, eighth nerve deafness and Hutchinson's teeth. This manuscript reports a case of late congenital syphilis presenting with Hutchinson's triad at an age of 7 years. These clinical features are related to syphilis present during pregnancy and at birth, however they commonly become apparent after 5-years of age.

Syphilitic aneurysm of the ascending aorta

Syphilitic aortic aneurysm is a rare occurrence in the antibiotic era, making the diagnose assumption even more infrequent. Nonetheless, this pathology can appear and should be suspected in patients with aortic aneurysm. We report a case of a 57-year old patient who presents with neurosyphilis and, in the following study, a large ascending aorta aneurysm is identified. The authors discuss the diagnostic challenge, the epidemiologic concerns, surgical indication and treatment and subsequent follow-up.

It is time to use treponema-specific antibody screening tests for diagnosis of syphilis

Assays that detect treponema-specific antibodies, which are either automated or can be done as point-of-care tests, have been developed, some of which are FDA approved. These assays have the advantage of being easily performed and demonstrate high sensitivity, both key features of an infectious disease screening test. As a result, many high-volume clinical laboratories have begun to offer a reverse syphilis testing algorithm where a treponema-specific test is used for screening, followed by a nontreponemal test (i.e., rapid plasma reagin [RPR]) to assess disease activity and treatment status. Concerns about physicians being able to understand and apply this new testing algorithm have been expressed (8). In this point-counterpoint, Michael Loeffelholz of the University of Texas Medical Branch at Galveston explains why his laboratory has adopted this reverse algorithmic approach. Matthew Binnicker of the Mayo Clinic, Rochester, MN, explains why the reverse algorithm may not be suitable for all clinical laboratories and every clinical situation.

Evaluation of a fully automated treponemal test and comparison with conventional VDRL and FTA-ABS tests

We evaluated analytic performances of an automated treponemal test and compared this test with the Venereal Disease Research Laboratory test (VDRL) and fluorescent treponemal antibody absorption test (FTA-ABS). Precision performance of the Architect Syphilis TP assay (TP; Abbott Japan, Tokyo, Japan) was assessed, and 150 serum samples were assayed with the TP before and after heat inactivation to estimate the effect of heat inactivation. A total of 616 specimens were tested with the FTA-ABS and TP, and 400 were examined with the VDRL. The TP showed good precision performance with total imprecision of less than a 10% coefficient of variation. An excellent linear relationship between results before and after heat inactivation was observed (R(2) = 0.9961). The FTA-ABS and TP agreed well with a κ coefficient of 0.981. The concordance rate between the FTA-ABS and TP was the highest (99.0%), followed by the rates between FTA-ABS and VDRL (85.0%) and between TP and VDRL (83.8%). The automated TP assay may be adequate for screening for syphilis in a large volume of samples and can be an alternative to FTA-ABS.

The immunopathobiology of syphilis: the manifestations and course of syphilis are determined by the level of delayed-type hypersensitivity

Syphilis has plagued mankind for centuries and is currently resurgent in the Western hemisphere. Although there has been a significant reduction of tertiary disease and recognition of facilitative interactions with human immunodeficiency virus infection, the natural history of syphilis has remained largely unchanged; thus, new strategies are required to more effectively combat this pathogen. The immunopathologic features of experimental syphilis in the rabbit; the course, stages, and pathology of human syphilis; and a comparison of human syphilis with leprosy suggest that the clinical course of syphilis and its tissue manifestations are determined by the balance between delayed-type hypersensitivity (DTH) and humoral immunity to the causative agent, Treponema pallidum. A strong DTH response is associated with clearance of the infecting organisms in a well-developed chancre, whereas a cytotoxic T-cell response or strong humoral antibody response is associated with prolonged infection and progression to tertiary disease. Many of the protean symptoms/appearances of secondary and tertiary human syphilis are manifestations of immune reactions that fail to clear the organism, due to a lack of recruitment and, more importantly, activation of macrophages by sensitized CD4 T cells. The Bacillus Calmette-Guerin vaccination can enhance DTH and has been shown to produce a low, but measurable, beneficial effect in the prevention of leprosy, a disease that shows a disease spectrum with characteristics in common with syphilis. In the prevention of syphilis, a potential vaccine protective against syphilis should be designed to augment the DTH response.

Late-stage neurosyphilis presenting with severe neuropsychiatric deficits: diagnosis, therapy, and course of three patients

Neurosyphilis is an infectious disease that has reappeared over the past two decades. It is caused by Treponema pallidum subspecies pallidum that can affect the central nervous system (CNS) during any stage of the disease. Besides early CNS involvement predominantly presenting with symptoms of meningitis, a parenchymal affection of the brain leading to severe neuropsychiatric symptoms particularly emerges at later stages, but is rarely seen nowadays due to early antibiotic treatment. Together with the clinical findings, a characteristic combination of serological and cerebrospinal fluid (CSF) abnormalities leads to the diagnosis of neurosyphilis and is required to assess its activity. However, particularly at later stages of disease and after antibiotic treatment, serological and CSF abnormalities may become ambiguous and, therefore, difficult to interpret. This can be accompanied by persisting or fluctuating neuropsychological deficits. To this day, no well-controlled clinical data exists concerning the treatment of late-stage neurosyphilis, neither on type, optimal dosage, duration, and long-term efficacy of antibiotic therapy. Therefore, treatment and follow-up of late-stage neurosyphilis are challenging tasks. Here, we present three cases of neurosyphilis with severe neuropsychiatric symptoms in non-immunocompromised patients and a review of the recent literature.

Getting the measure of syphilis: qPCR to better understand early infection

OBJECTIVES

Until recently, PCR had been used to detect but not quantify Treponema pallidum. To understand infection kinetics of this uncultivable organism, a real-time PCR assay was developed to quantify 47 kDa membrane lipoprotein gene DNA (tpp47).

METHODS

Assay specificity was determined against DNA from humans, skin organisms and sexually transmitted pathogens. tpp47 DNA (Nichols strain) was used to construct a standard curve for T pallidum quantification. Blood and ulcer samples were obtained from 99 patients being investigated or screened for syphilis and tpp47 was quantified.

RESULTS

The assay was specific, not cross-reactive with other organisms tested and sensitive, with a detection limit of a single copy of tpp47 DNA. For ulcer samples, the assay was 100% sensitive and 97.14% specific. Sensitivity fell to 34.1% for blood samples but specificity remained high (100%). tpp47 DNA was more commonly detected, and at a higher copy number, in blood of patients with secondary infection (sensitivity 57.89%) compared with primary infection. Quantity of tpp47 DNA was higher in primary infection ulcers, especially in HIV-1-positive patients, than in ulcers persisting into secondary disease.

CONCLUSIONS

Quantifying T pallidum provides insight into syphilis infection kinetics: Ulcers of primary disease in HIV-1-positive patients are perhaps more infectious and the presence and load of T pallidum bacteraemia is variable, with a peak in the secondary stage. Quantitative PCR has the potential to map T pallidum infection and to highlight the impact of HIV on syphilis.

Syphilis test availability and uptake at medical facilities in southern China

OBJECTIVE

To examine syphilis testing capacity, screening coverage rates and types of syphilis tests used in medical facilities in southern China.

METHODS

Eleven of the 14 municipalities in Guangdong province participated. Data on syphilis testing capacity, screening coverage and types of syphilis tests used were collected from all types of public medical facilities offering prenatal care (n = 109). A total of 494 680 women who delivered during 2004-2008 were studied.

FINDINGS

In 2008, 54 196 pregnant women (43.1%) were not screened for syphilis. Among such women, 32 863 (60.6%) attended clinics without any syphilis testing capacity and 21 333 (39.4%) attended clinics that performed testing but were not screened. The likelihood of not having syphilis test capacity was much higher for hygiene stations (odds ratio, OR: 10; 95% confidence interval, CI: 4-25), services at the township level (OR: 33; 95% CI: 10-100) and services with ≤ 1000 deliveries per year (OR: 1.002; 95% CI: 1.001-1.003). These same service characteristics correlated with lower screening coverage rates (P < 0.01). Only one antenatal clinic had the capacity to conduct both treponemal and non-treponemal tests for diagnosing syphilis.

CONCLUSION

Syphilis screening is available in very few of the basic medical facilities offering prenatal care where most neonates in southern China are delivered. In light of this and of the increasing incidence of syphilis in the area, expanding point-of-care rapid syphilis testing is a priority.

A case of adrenal insufficiency secondary to syphilis and difficulties in the diagnostic work-up

We report a case of Addison's disease presumed to be secondary to syphilis. The patient presented with adrenal failure and a maculopapular rash on his trunk and palms. Syphilis was suspected but the non-treponemal serological test used (the rapid plasma reagin test (RPR)) was falsely negative due to the prozone phenomenon. Treatment with benzathine penicillin resulted in normalization of adrenal function and resolution of the cutaneous findings. Repeat testing of the previously obtained serum sample showed the RPR to be positive on increasing dilutions of serum, consistent with the prozone effect.

Resurgence of congenital syphilis: diagnosis and treatment

Despite comprehensive antenatal screening recommendations and inexpensive treatment, congenital syphilis has long been and continues to be a public health concern, causing substantial morbidity and adverse outcomes. The following article reviews syphilis etiology and presentation, clinical disease, laboratory diagnosis, and treatment of congenital syphilis. A case will be presented describing a 31-week male infant exposed to infectious syphilis in utero. The neonate presented with classic signs of infection at birth. After initial serology testing of the infant, appropriate treatment was commenced. The infant received crystalline penicillin G for a period of ten days in consultation with pediatric infectious disease specialists. As expected, the infant's rapid plasma reagin (RPR) titers declined by three and six months of age. An interdisciplinary approach provided safe and optimal care for this infant. He was discharged, stable, and thriving at 38 weeks corrected age. Long-term multidisciplinary management and follow-up were arranged.

A case of congenital syphilis with Hutchinson's triad

Late congenital syphilis is a rare entity and its early diagnosis and treatment is essential to prevent significant morbidity. We are reporting a case of late congenital syphilis presenting with Hutchinson's triad at an age of 14 years.

Molecular detection of Treponema pallidum sp. pallidum in blood samples of VDRL-seroreactive women with lethal pregnancy outcomes: a retrospective observational study in northern Brazil

INTRODUCTION

Although control measures of maternal and congenital syphilis are available in Brazil, difficulties exist within the healthcare network in providing a laboratory diagnosis of the infection during the prenatal period. The objective of this study was to confirm the presence of Treponema pallidum by PCR in women with positive VDRL serology and lethal pregnancy outcomes, i.e., abortion, stillbirth and neonatal death.

METHODS

A retrospective study was conducted on VDRLseroreactive women with lethal pregnancy outcomes admitted to the Fundação Santa Casa de Misericórdia do Pará (FSCM-PA) between January and July 2004. Serum samples and DNA from whole blood were obtained at the time of screening by the VDRL test. These samples were analyzed by IgG ELISA, IgM FTA-Abs and simple PCR (polA).

RESULTS

During the study period, 0.7% (36/4,912) of women with lethal pregnancy outcomes presented a positive VDRL test. The polAgene was amplified in 72.7% (24/33) of these women, with 55.6% (20/36) and 94.4% (34/36) presenting IgM and IgG antibodies against T. pallidum, respectively. Comparison of these results showed a significant difference, with agreement between the PCR and IgM FTA-Abs results, suggesting that maternal syphilis was an active infection. No basic cause of death of the conceptus was reported in 97.2% (35/36) of cases. Among women who were submitted to the VDRL test during the prenatal period, only four of the nine seroreactive patients underwent treatment.

CONCLUSIONS

The high frequency of syphilis in the group studied indicates the fragility of the service of infection diagnosis, treatment and monitoring, compromising epidemiological control.

Evaluation and Management of Syphilis in the HIV-Infected Patient

Rates of syphilis continue to increase in the United States and HIV-infected patients make up a large proportion of cases. The interaction between syphilis and HIV is complex and still incompletely understood. Although diagnosis and management of HIV-infected patients with syphilis is, in general, similar to HIV-uninfected patients, the former may be at increased risk for complications. Recent data suggest that HIV-induced immunosuppression may alter the course of syphilis and that highly active antiretroviral therapy may have a beneficial effect on syphilis outcomes. Prevention strategies consisting of sexual risk assessments, condom use, treatment of infected partners, yearly screening for syphilis of all HIV-infected patients, and enhanced clinical and serologic follow-up of treated HIV-infected patients are critical components of a comprehensive approach to care.

Congenital syphilis: A guide to diagnosis and management

Although congenital syphilis is a rare disease in Canada, infected infants may experience severe sequelae, including cerebral palsy, hydrocephalus, sensorineural hearing loss and musculoskeletal deformity. Timely treatment of congenital syphilis during pregnancy may prevent all of the above sequelae. However, the diagnosis of suspected cases and management of congenital syphilis may be confusing, and the potential for severe disability is high when cases are missed. The present review provides assistance to practitioners in the diagnosis of suspected cases and management of children with presumed or confirmed infection.