Rapid Plasma Reagin Research Articles

Prevalence of syphilis infection among migrant workers in Qatar: a nationwide cross-sectional survey

ObjectivesScant data are available on syphilis infection within migrant populations worldwide and in the population of the Middle East and North Africa region. This study investigated the prevalence of both...

Management of detected syphilis in pregnancy adheres to guideline recommendations, but the crisis of congenital syphilis persists.

Infectious syphilis among women of reproductive age continues to rise in many countries including Australia, with a resultant increase in congenital syphilis. In response, new guidelines for management of syphilis in pregnancy were published in Queensland, Australia in 2018. This study evaluates the management of women diagnosed with syphilis in pregnancy in South-East Queensland (SEQ) after release of this guideline. This retrospective review of notification data identified women in SEQ who had a positive syphilis serology during pregnancy, without evidence of adequate treatment prior to the pregnancy, between January 2019 and December 2021 inclusive. Maternal demographics and pregnancy details including syphilis staging, testing and management were extracted, with management assessed against the 2018 Queensland syphilis in pregnancy guideline. Of the 42 women identified, 79% were diagnosed in the first or second trimester, 69% had early-stage syphilis at the time of diagnosis and 86% were asymptomatic at the time of diagnosis. All, including the eight (19%) Aboriginal and/or Torres Strait Islander women identified, completed stage-appropriate treatment with penicillin, 83% completed treatment four weeks prior to delivery and 60% achieved a four-fold reduction in rapid plasma reagin at time of delivery. Our findings suggest compliance with syphilis in pregnancy management recommendations has improved in SEQ since release of the 2018 guidelines. However, congenital syphilis rates continue to rise; further initiatives addressing barriers to timely testing and management of syphilis in pregnancy are urgently needed at both healthcare system levels and for individual women.

Kinetics of RPR Decline in Pregnant Persons Treated for Syphilis in Pregnancy and Their Infants.

Congenital syphilis is a re-emerging infectious threat in areas of North America. The purpose of this study was to quantitatively describe the rate of decline of nontreponemal (rapid plasma reagin, RPR) titers in pregnant persons with syphilis and their infants. In a retrospective review, we included 120 pregnant persons with 563 reactive RPR measurements (median 5, range 2 to 11 per person) and 35 infants with 81 RPR measurements (median 2, range 2 to 6 per infant). First-order decay, second-order decay, and a mathematical model representing functional FcRn-mediated antibody recycling were fitted to individual patient RPR trajectories. The RPR titers decreased with a median half-life of 39 days (IQR 28-59) and 27 days (IQR 17-41) in birthing parents and infants, respectively. The half-life varied with the initial RPR titer, suggesting that the kinetics of RPR decline was not first-order. A mathematical model accounting for saturable antibody recycling explained the longevity of RPR reactivity, predicted the observed non-linear kinetics, and fit the empiric data well. In summary, RPR titers decline with a half-life of roughly one month; however, the elimination does not follow first-order kinetics. Saturable antibody recycling may explain the prolonged and non-linear elimination of nontreponemal antibodies.

Improving the detection of congenital syphilis: reviewing test utility and adherence to recommendations

Western Australia (WA) has experienced a resurgence of congenital syphilis. Appropriate microbiology testing of the neonate is recommended to confirm infection, including syphilis immunoglobulin M (IgM), rapid plasma reagin (RPR) paired with a maternal sample, and polymerase chain reaction (PCR) on placenta and nasal swabs. We examined the performance of microbiology tests in confirmed congenital syphilis cases and the adherence to testing recommendations in those assessed as high risk. We reviewed the microbiology results of confirmed congenital syphilis cases in WA between 1 January 2018 and 31 December 2023. In addition, microbiology testing of neonates from metropolitan Perth identified as being at a high risk of congenital syphilis between 1 January 2021 and 31 October 2023 was reviewed. Eighteen congenital syphilis cases were identified; data were unavailable for a case born interstate. Of the 17 included cases, the case fatality rate was 35% (6/17; five stillbirths and one perinatal death). Placenta tissue PCR was positive in all stillbirths. Of the 12 live births, 83% were symptomatic at delivery. Perinatal testing was performed in 11 live births (11/12); IgM was detected in 55% (6/11). Placenta tissue PCR was positive in 88% (7/8 tested). Nasal swab PCR was positive in 57% (4/7 tested) of cases. There were 22 neonates classified as being at a high risk for congenital syphilis infection; all had IgM and RPR testing. Syphilis PCR was performed on placenta tissue samples in 64% (14/22) and on nasal swabs in 64% (14/22) of cases. Comprehensive microbiological testing, including syphilis IgM and placenta tissue PCR, is required to confirm congenital syphilis infection. Continuous evaluation of testing will be crucial for individual case detection and monitoring of the ongoing outbreak. Given the risk of incomplete specimen collection, our data support ​the adoption of a risk-based approach for neonates at risk of congenital syphilis, with management guided by maternal serology and treatment history.

Concomitant primary and secondary syphilis: a case series from a reference center in Mexico

Primary syphilis is characterized by the presence of a chancre and secondary syphilis by the presence of syphilis. The presence of chancres within secondary syphilis have been reported, however, this form of presentation is rare. Patients with synchronous diagnosis of primary and secondary syphilis were included. They underwent a reverse sequence algorithm for syphilis diagnosis with a rapid syphilis test, if positive, a rapid plasma reagin (RPR) or venereal disease research laboratory (VDRL) tests were performed. A total of 15 patients were included. All were men. In primary syphilis, penile chancre predominated in 13 patients (86.6%), and one (6.7%) was in the tongue. In secondary syphilis syphilitic roseola was the most common type of presentation in 10 patients (66.6%), followed by the palmoplantar plaques in 6 patients (40%) and condyloma lata in 2 patients (13.3%). One patient presented alopecia in a “moth-eaten” pattern and this presentation coexisted with a condyloma lata and the palmoplantar plaques. Other patient presented with syphilitic roseola, palmoplantar plaques and condyloma lata. Clinical presentation as coexistent primary-secondary syphilis will become more frequent. First contact physicians and dermatologists would have to take more in consideration infrequent and atypical clinical forms of this disease.

Persistent syphilitic ocular manifestations despite treatment: a case series

BackgroundPenicillin has remained the most effective treatment for syphilis for several decades. Syphilitic retinal manifestations may persist following treatment and cause visual problems. In this case series, we describe three syphilis patients with persistent posterior segment manifestations due to chronic inflammation, incomplete treatment, and reinfection.Case seriesRecommended initial treatment for all patients was 14 days of intravenous penicillin. Oral prednisone was added 48 h after initiation of penicillin therapy. Case 1: A 48-year-old female presented with gradual vision loss for two months. Fundus imaging revealed syphilitic outer retinopathy (SOR), papillitis, and acute syphilitic posterior placoid chorioretinopathy (ASPPC). After treatment, she had persistent cystoid macular edema (CME) and was treated with intravitreal triamcinolone injections and ketorolac drops. Case 2. A 24-year-old male presented with sudden vision loss for two days. On imaging, he had ASPPC, papillitis, and SOR. IV penicillin treatment was given for 10 days only. He had persistent SOR and was retreated with doxycycline and prednisone. Case 3: A 52-year-old male presented with eye pain and visual loss for one week. There was evidence of ASPPC and papillitis on imaging. One month after treatment, he had persistent papillitis and was restarted on oral prednisone. One year later, he was found to have recurrent ASPPC and was confirmed to be reinfected with syphilis, for which he was retreated.ConclusionWhen treating persistent syphilitic ocular manifestations, we recommend checking that the penicillin treatment was complete and the RPR titers are declining. If both hold true, then the affected eye should be treated with anti-inflammatory therapy. Other factors that contribute to poor visual prognosis include treatment delay, poor initial visual acuity, macular edema, and HIV coinfection.

A Complex Case of Extrahepatic Biliary Obstruction: Syphilitic abdominal lymphadenitis

Abstract Introduction/Objective Syphilis, a sexually transmitted disease that is caused by spirochete Treponema pallidum, can vary widely in presentation. Infective lymphadenitis due to syphilis have been reported before in cervical and inguinal lymph nodes.Here we present an interesting case of syphilitic lymphadenitis with unusual presentation and location. Methods/Case Report A 30-year-old male with no past medical history presented with epigastric pain, fever, jaundice, weight loss, and night sweats. Computed tomography imaging revealed a 4.1 cm solid mass at the porta hepatis with involvement of perihepatic lymph nodes, raising suspicion of malignancy. All serological tumor markers were negative. The patient underwent ERCP with biliary drainage to relieve obstructive jaundice. Bile duct brushing and liver biopsy at that time were non-diagnostic. Later the patient underwent laparoscopic lymph node excision. Histological examination of the lymph node showed intact follicular architecture with an increase in plasma cells and sinus histiocytes, without evidence of carcinoma or lymphoma cells. Flow cytometry on the lymph node showed polytypic B-cells and antigenically normal T-cells with CD4: CD8 ratio of 0.5 showing relatively excess of CD8 positive cytotoxic cells. Positive staining for Treponema pallidum with appropriate control highlighted micro-organisms suggestive of secondary syphilitic infection. This evidence was later supported by positive rapid plasma reagin (RPR) test. He subsequently tested positive for Human immunodeficiency virus (HIV-1). Results (if a Case Study enter NA) NA Conclusion In summary, appropriate histologic and serological testing lead to timely diagnosis in this case. This case contributes to the limited literature on syphilitic lymphadenitis and reports the first documented case of isolated intra- abdominal lymph node involvement.

Macular Star and Neuroretinitis with Optic Disk Edema

Neuroretinitis is an inflammatory disorder of the eye presenting with unilateral visual loss, optic disc edema, and subsequent formation of a macular star. Neuroretinitis can be classified as idiopathic, infectious and recurrent. Following a detailed patient history, essential work-up should include Bartonella antibody titers, the rapid plasma reagin (RPR) test, the tuberculin skin test, ACE and lysozyme levels, and a two-view chest X-ray. Among infectious etiologies of neuroretinitis, cat scratch disease caused by Bartonella henselae is the most frequently observed, accounting for two-thirds of cases. Recurrent neuroretinitis is characterized by poorer visual recovery and visual field loss. Patients should be informed about the possibility of recurrence to prevent severe vision loss.

8386 The Evolving Face of The Great Masquerader - Panhypopituitarism Associated with Neurosyphilis

Abstract Disclosure: M. Yabe: None. Z. Lin: None. F. Joseph: None. G. Philip: None. R. Silver: None. L. Callejas: None. J. Giunta: None. Untreated syphilis is on the rise in the United States. The CDC reported syphilis cases in newborns have increased 10-fold over a decade in November 2023, signifying the emergence of untreated infections. Pituitary involvement in syphilis is a very rare phenomenon, and endocrinological investigation is often overlooked. This will be the second reported case of neurosyphilis with pituitary involvement in a non-HIV infected patient. A 45-year-old female with no significant past medical history was admitted to the hospital with progressive neurological symptoms of intermittent left-side headache, hearing loss with tinnitus, and gait instability. Postcontrast MRI Brain revealed multifocal leptomeningeal enhancement involving supratentorial and infratentorial regions. Thickening of the enhanced pituitary infundibulum was also noted. Subsequent RPR titer showed 1:16 and lumbar puncture revealed CSF-VDRL titer 1:32, with pleocytosis 83 cells/uL, CSF-glucose 19 mg/dL, and CSF-protein 370 mg/dL. The patient completed Penicillin G 4 million/units intravenous every 4 hours for 14 days, with repeat MRI showing significant interval decrease in previously described extensive supratentorial and infratentorial leptomeningeal enhancement. However, there is no record of her sexual partner receiving treatment. The patient was readmitted one year later after a fall while displaying dysmetria. MRI Brain with contrast revealed a small subacute infarct along the right frontal corona radiata and pituitary gland measuring up to 1.2 cm in craniocaudal dimension compared to 0.4 cm on the prior exam. This prompted evaluation of pituitary hormones: FSH 0.8 IU/L, LH <0.3 IU/L, and ACTH 6.3 pg/mL, with normal serum growth hormone and prolactin levels. Further investigation revealed morning cortisol 2.5 ug/dL, thyrotropin < 0.2 uIU/mL, and free thyroxine 0.63 ng/dL. Radiological evidence is suspicious of inflammatory etiology of the pituitary gland. The patient was discharged with endocrinology follow-up and plan to perform a pituitary gland biopsy as an outpatient for confirmatory result. The association of neurosyphilis and hypophysitis leading to panhypopituitarism in a non-HIV infected patient was first reported in 2015. Since then, there remains limited research regarding their association due to rarity of pituitary involvement in neurosyphilis. With untreated syphilis on the rise and increased availability of MRI, clinicians should expect to encounter more cases of neurosyphilis with pituitary involvement in the future. Early detection of panhypopituitarism in those with positive CSF-VDRL titer could lead to better clinical outcomes. It is paramount that these cases are documented to emphasize pituitary involvement in neurosyphilis and encourage a low threshold to initiate endocrinological testing in the future. Presentation: 6/3/2024

Clinical and Laboratory Characteristics, Diagnosis, and Treatment of Patients with Neurosyphilis in Emergency Department: A Retrospective Study of 12 Patients.

Syphilis, caused by Treponema pallidum, presents a diagnostic challenge due to its diverse clinical manifestations. Neurosyphilis has seen a resurgence in recent years, particularly among men who have sex with men and those living with HIV. Diagnosis of neurosyphilis in emergency settings is challenging due to its varied neurological presentations. This study aims to serve as a reference for dermatologists and neurologists in diagnosing and treating neurosyphilis. This retrospective study analyzed patients who presented with neuropsychiatric symptoms and were ultimately diagnosed with neurosyphilis. These patients were collected from the emergency department in Peking Union Medical College Hospital between January 2018 and November 2023. The medical history, clinical symptoms, laboratory examinations, cranial MRI characteristics, and treatment regimens of these patients were investigated. Among the included 12 neurosyphilis patients, memory deterioration was observed in 8 out of the 12 neurosyphilis patients. Diagnosis often resulted in delays, with misdiagnoses mainly including Alzheimer's disease, stroke, and epilepsy. Neuroimaging revealed various abnormalities, predominantly affecting ventricular and temporal regions. Treatment with penicillin-based regimens varied in compliance, with only a minority of patients adhering to guidelines. Treatment outcomes were inconsistent, with some patients experiencing irreversible neurological damage and fluctuating serum rapid plasma reagin (RPR) titers. Diagnosis of neurosyphilis in the emergency department remains challenging, necessitating awareness of its varied neurological presentations. Enhanced diagnostic strategies are imperative to accelerate treatment initiation and improve outcomes for affected individuals.

Congenital Syphilis With Multiple Bone Fractures

We report a rare case of multiple fractures occurring in a 3-month-old boy with congenital syphilis (CS). His mother was diagnosed by a gynecologist with syphilis on a screening test before his birth. After birth, a serological panel revealed positive rapid plasma reagin and treponema pallidum hemagglutination assay test results. On the first visit, his left humerus was broken. Whole-body screening radiographs showed multiple fractures of both distal radii and the right first metatarsal. Immobilization was performed with a plastic splint, and callus formation of his humerus was seen after 3 weeks. CS cases have been increasing both in Japan and abroad in recent years. Orthopaedic surgeons should not forget the possibility of CS as a differential for fractures, especially in infants younger than 3 months born to syphilis-infected mothers.

Posterior Segment Manifestations of Syphilis and Correlation With Serologic Markers of Infection.

Retrospective analysis correlating serologic titers of ocular syphilis with posterior segment manifestations. This study consisted of 40 patients (80 eyes imaged, 68 affected) with positive rapid plasma reagin (RPR) and Treponema Pallidum immunoglobulin G. We collected demographic and presentation data including HIV status, absolute CD4 count, RPR, cerebrospinal fluid-venereal disease research laboratory (CSF-VDRL) test, and retinal zone. We categorized imaging into syphilitic outer retinopathy (SOR), acute syphilitic posterior placoid chorioretinopathy, retinitis/chorioretinitis (RC), and papillitis. Multivariate analysis correlated HIV status, RPR, and VDRL titers with posterior segment findings and zone. Mean age of 42.8 ± 10.7 years, with 70% male patients. Presenting visual acuity (logMAR) 0.66 ± 0.74 did not correlate with RPR, nor was it associated with papillitis, RC, or acute syphilitic posterior placoid chorioretinopathy. Higher RPR (≥ 1:128) positively associated with SOR (P = 0.031) and zone 1 (odds ratio [OR], 1.62; P = 0.02), but negatively associated with zone 2 (OR 0.35; P = 0.005). HIV positivity increased RC odds (OR, 4.45; P = 0.047). Higher RPR correlated with SOR and zone 1, whereas HIV positivity correlated with RC. [Ophthalmic Surg Lasers Imaging Retina 2024;55:511-516.].

Prevalence and risk factors of curable sexually transmitted and reproductive tract infections and malaria co-infection among pregnant women at antenatal care booking in Kenya, Malawi and Tanzania: a cross-sectional study of randomised controlled trial data

ObjectivesMalaria and curable sexually transmitted and reproductive tract infections (STIs/RTIs) are associated with adverse pregnancy outcomes. This study reports the prevalence and risk factors of curable STIs/RTIs, STI/RTI co-infection and...

Higher rates of laboratory-confirmed cases of syphilis in Western Canadian blood donors compared with Eastern Canadian blood donors following a period of societal re-opening.

There is a growing infectious syphilis outbreak in Western Canada. Although blood donors are screened for syphilis risks, some blood donors will still be confirmed test-positive for syphilis. This study compares the characteristics of confirmed test-positive syphilis donations in both Western Canada and Eastern Canada, November 2022-August 2023. Donors were defined as Western or Eastern Canadian. Blood donations were tested for syphilis using the PK-TP assay (Beckman Coulter PK7300 Automated Microplate System). Confirmatory Treponema pallidum particle agglutination (TPPA) and rapid plasma reagin (RPR) assays were performed by one of two reference laboratories. An RPR titre ≥1:8 was used as a proxy for possible infectious syphilis. Rates of laboratory-confirmed syphilis were higher in Western (n = 43, 13.4/100,000 donations) versus Eastern donors (n = 19, 4.7/100,000 donations; Fisher's exact test, two-sided, p ≤ 0.0001). Most syphilis confirmations were in first-time donors (Western Canada n = 31/43, 72.1%, Eastern Canada 12/19, 63.2%). Although rates of laboratory-confirmed syphilis were higher in Western versus Eastern donors, Western donors did not have higher rates of infectious syphilis. Further studies might assess whether donors with laboratory-confirmed syphilis understood pre-donation screening questions or were completely unaware of a past infection.

Prevalence of sexually transmitted infection in pregnancy and their association with adverse birth outcomes: a case–control study at Queen Elizabeth Central Hospital, Blantyre, Malawi

BackgroundThere are limited data on the epidemiology of sexually transmitted infections (STI) and their contribution to adverse birth outcomes (ABO) in sub-Saharan Africa (SSA). We performed a case–control study to...

Laboratory evaluation of the Chembio DPP Syphilis Screen & Confirm point-of-care test on serum and simulated blood samples

Introduction: Syphilis infections are increasing in Canada, and traditional serological diagnostics pose barriers for vulnerable and marginalized populations at greatest risk. Point-of-care tests (POCTs) offer solutions, yet none were available in Canada until recently. The Chembio Dual Path Platform (DPP) Syphilis Screen & Confirm (SSC) is one of the first POCTs that helps distinguish active infection from non-infectious syphilis. This study evaluates the reliability of the Chembio DPP SSC to diagnose syphilis infection. Methods: One hundred clinical samples with known syphilis serology (chemiluminescent microparticle immunoassay [CMIA] and rapid plasma regain [RPR]) results were used to evaluate the Chembio DPP SSC. CMIA–ve (n = 20), CMIA+ve RPR–ve (n = 40), and CMIA+ve RPR+ve (n = 40) samples represented negative, past, and presumed active infection, respectively. Samples were used in two formats: serum and simulated blood. Two laboratory technicians read the test visually, and with the manufacturer's DPP Micro Reader, in blinded fashion. Results: Overall sensitivity of the Chembio DPP SSC to distinguish presumed active infection from non-infectious syphilis (past infection and no infection) with visual reads were 52.50% (serum) and 55.00% (simulated blood). Sensitivity increased using the DPP Micro Reader to 90.00% (serum) and 97.50% (simulated blood). Specificity with visual reads were 98.33% (serum) and 95.00% (simulated blood) compared to Micro Reader results of 88.30% (serum) and 80.00% (simulated blood). For the non-treponemal portion of the POCT with visual reads, the sensitivity increased with increasing RPR titers. Low RPR titers <1:4 only had a sensitivity of 42.86% (serum) and 14.29% (simulated blood). Discussion: The laboratory evaluation of the Chembio DPP SSC shows promise in detecting active syphilis, particularly in samples with RPR titers >1:4. However, the need for the Micro Reader for more accurate results is a limitation of the POCT, and financial constraints may pose barriers to some users. Further field evaluation is warranted.

Leber’s Hereditary Optic Neuropathy Following Unilateral Syphilitic Optic Neuritis

This report describes a case of Leber’s hereditary optic neuropathy (LHON) following unilateral syphilitic optic neuritis. A 31-year-old man presented with a four-day history of decreased vision in his left eye. At the initial visit, the patient’s best corrected visual acuity (BCVA) was 1.2 and 0.02 in the right and left eye, respectively, along with a relative afferent pupillary defect in the left eye. Goldmann visual field testing revealed a central absolute scotoma and an enlarged blind spot in the left eye. Serological testing confirmed syphilis with rapid plasma reagin positivity. The patient was diagnosed with syphilitic optic neuritis and treated with intravenous penicillin G (24 million units daily) for two weeks. After two weeks of therapy, his left BCVA improved to 0.4 after two months. However, five months later, despite completing syphilis treatment, the patient developed acute painless visual loss in both eyes. His BCVA decreased to 0.8 and 0.05 in the right and left eyes, respectively. Goldmann visual field testing revealed a central absolute scotoma and an enlarged blind spot in both eyes. After two weeks, BCVA progressively declined to 0.4 in the right and 0.04 in the left eye. Furthermore, Goldmann visual field testing revealed an enlarged central absolute scotoma and blind spot in both eyes. Six months after the initial examination, his BCVA was counting fingers and 0.02 in the right and left eye, respectively. The optic discs appeared diffusely pale in both eyes. Genetic testing for LHON revealed a pathologic mtDNA 11778 point mutation. This case underscores the importance of considering the possibility of LHON if acute or subacute vision loss occurs subsequently or simultaneously in both eyes and remains unresponsive to treatment.

Syphilis Positivity Among Men Who Have Sex With Men With Direct, Indirect, and No Linkage to Female Sex Partners: Exploring the Potential for Sex Network Bridging in Baltimore City, MD.

Syphilis epidemics among women and men who have sex with men (MSM) may be connected, but these connections are poorly understood. Using egocentric network data from a US urban MSM cohort, we examined sociodemographics, behaviors, and syphilis positivity among MSM with (1) direct (MSM who report sex with women, MSMW); (2) indirect (MSM who only report male partners, some of whom are MSMW, MSMO/W); and (3) no (MSM who only report male partners and whose partners only have sex with men, MSMO/O) connection to women. Sexually active MSM aged 18 to 45 years were administered behavioral and network interviews (recall period: 3 months) and syphilis/HIV testing. Syphilis positivity was defined as rapid plasma reagin titer ≥1:8. Modified Poisson regression was used to test for differences across groups. Among 385 MSM, 14.5% were MSMW and 22.3% were MSMO/W. MSMW and MSMO/W were significantly more likely than MSMO/O to report sex behaviors associated with increased syphilis acquisition/transmission risk, including ≥2 sex partners (MSMW: adjusted prevalence ratio [aPR], 1.28 [0.98-1.68]; MSMO/W: aPR, 1.35 [1.09-1.69]) and concurrent sex partners (MSMW: aPR, 1.50 [1.17-1.92]; MSMO/W: aPR, 1.39 [1.11-1.74]), and for MSMW only, transactional sex (aPR, 2.07 [1.11-3.88]). Syphilis positivity was 16.4% and was lower among MSMW (9.4%) and MSMO/W (14.1%) than MSMO/O (18.5%), but differences were not significant. There may be considerable connectivity between MSM and female sex partners that could facilitate syphilis transmission, and behaviors that increase acquisition/transmission risk among MSMW and MSMO/W may be distinct from MSMO/O. Future work should focus on examining the context and temporal patterns of sex partnerships among MSMW and MSMO/W.

Lack of Serological Response by Delivery to Syphilis Treatment Does Not Impact Pregnancy Outcomes.

Objectives: Maternal syphilis can lead to serious adverse pregnancy outcomes, including neonatal death. A 4-fold decline in blood non-treponemal titer at six months after the treatment of syphilis compared to the baseline is considered as an adequate serological response. However, the duration of normal human gestation does not allow the ascertainment of an adequate serological response. Aim: The aim of this study was to assess correlations between the lack of a 4-fold decrease in non-treponemal titer by delivery after syphilis treatment and fetal and newborns' condition and serological outcomes. Methods: Fourteen pregnant patients (gestational age 16-22 weeks) diagnosed with early syphilis (secondary or latent) were treated with intramuscular benzathine penicillin and subsequently monitored clinically, serologically, and ultrasonographically at monthly intervals. Based on the non-treponemal test results at delivery, patients were stratified into two groups: those with a 4-fold decline in titers and those without such a decline. All newborns were clinically and serologically assessed for congenital syphilis at birth and then monitored until serological tests became negative. Results: Fifty percent of the included women did not achieve a 4-fold decline in non-treponemal titer by delivery. Patients from the group showing a 4-fold decline in RPR titer at delivery and those without such a decline did not differ in basic demographic and clinical characteristics or in ultrasound parameters used for fetal assessment. Based on the clinical and laboratory assessments of newborns on the day of delivery and during a 6-month follow-up, none were diagnosed with congenital syphilis or required treatment for syphilis. Conclusions: The lack of an adequate serological response to syphilis therapy by delivery among patients treated between 16 and 22 weeks of pregnancy does not appear to be associated with adverse fetal and neonatal outcomes.

Seasonal increase in syphilis screening reactivity rates in whole blood donors, United States, 2011-2023.

In December 2021, the U.S. Food and Drug Administration published a letter to clinical laboratory staff and healthcare providers detailing a risk of false Rapid Plasma Reagin (RPR) when using the Bio-Rad Laboratories BioPlex 2200 Syphilis Total & RPR kit in people who had received COVID-19 vaccination; Treponema pallidum particle agglutination assays did not appear to be impacted by this issue. We evaluated reactivity rates of syphilis screening with negative confirmatory testing at our institution by year and seasonality. We performed a retrospective study of routine syphilis testing of whole blood (WB) collections at an academic hospital-based donor center in the eastern United States. All WB donations from 2011 to 2023 which demonstrated reactive syphilis screening (Beckman Coulter PK TP Microhemagglutination) with negative confirmatory testing (CAPTIA Syphilis (T. pallidum)-G) were evaluated. Reactivity rates by year and season of donation were compared using unpaired t-tests. A total of 109 WB donations from 86 unique donors who donated from 2011 to 2023 screened reactive for syphilis with negative confirmatory testing. The unconfirmed syphilis reactivity rate increased from 2018 to 2023 (mean: 0.360%) compared to 2011-2017 (mean: 0.071%, p < .05). An autumnal peak in unconfirmed reactives was observed. The unconfirmed syphilis reactivity rate among WB donors at our institution increased markedly since 2017 compared to the 7 years prior and doubled from 2020 to 2021. No testing assay changes explain these results. The autumnal peak in unconfirmed reactives suggests a possible environmental trigger such as viral infection or vaccination.