Correction: Influenza vaccination coverage and factors associated with severe laboratory-confirmed influenza-related illness in patients receiving care at a tertiary hospital in Catalonia (Spain) during the 2018-2019 epidemic season.

[This corrects the article DOI: 10.1371/journal.pone.0260397.].

Detection and Prevalence of Macrolide and Fluoroquinolone Resistance in Mycoplasma genitalium in Badalona, Spain.

Macrolide and fluoroquinolone resistance (MLr/FQr) in Mycoplasma genitalium (MG) infections is concerning worldwide. Current guidelines recommend performing MLr detection in MG-positive cases to adjust antimicrobial therapy. We aimed to evaluate the usefulness of PCR followed by pyrosequencing for MLr detection in comparison with a one-step commercial assay and to assess the prevalence of MLr and FQr in Badalona, Spain. A total of 415 MG-positive samples by Allplex STI-7 (Seegene) were analyzed for MLr detection by pyrosequencing. From those, 179 samples were further analyzed for MG and MLr by ResistancePlus® MG kit (SpeeDx) and 100 of them also for fluoroquinolone resistance (FQr) by sequencing the parC gene. Regarding MG detection, Allplex and Resistance Plus® showed an overall agreement of 87%, but this value rose to 95.4% if we compare them for MLr detection. Prevalence of MLr was 23.1% in Badalona, but this rate increased to 73.7% in the HIV-positive patients cohort. FQr detection showed 3% of resistant strains. Pyrosequencing is a convenient and cheap technique for MLr detection, but one-step tools should be considered in high-throughput laboratories. Despite the fact that MLr remained moderate and FQr was low in our study, simultaneous MG and MLr detection would improve patient's management applying resistance-guided treatment strategies.

Influenza vaccination coverage and factors associated with severe laboratory-confirmed influenza-related illness in patients receiving care at a tertiary hospital in Catalonia (Spain) during the 2018-2019 epidemic season.

INTRODUCTION: Influenza vaccination rates in risk groups remain suboptimal. Evidence supporting a significant association between influenza vaccination and severe illness is limited. METHODS: We retrospectively analyzed the epidemiological characteristics of out- and inpatients with laboratory-confirmed influenza infection attended during the 2018-19 epidemic season. Influenza vaccination coverage by indication was analyzed. Logistic regression was used to compare the odds of vaccination between severe and non-severe influenza-positive patients. Severe cases were defined as presenting pneumonia, admission to critical care units and/or death. RESULTS: The overall vaccination coverage among influenza-positive patients was 30.4%. In subjects with ≥ 1 indication for vaccination, the vaccination coverage was 42.4%. By indication, coverage rates were: 52.5% in patients aged ≥ 59 years, 42.2% in obese patients, 29.2% in immunosuppressed subjects and 6.5% in pregnant women. In patients with underlying chronic diseases, a higher coverage was found in patients with cognitive impairment (77%), muscular dystrophy (63.6%) and renal disease (60.4%). The multivariate logistic regression model showed severe influenza-related illness was associated with a lack of influenza vaccination before seeking care during the 2018-2019 season [0.59 (95%CI 0.36-0.97); p = 0.038], older age [1.01 (95%CI 1.00-1.02); p = 0.009] and current or former smoking status [1.63 (95%CI 0.84-3.18) and 2.03 (95%CI 1.16-3.57); p = 0.031], adjusted by underlying disease. CONCLUSION: Adjusting by age, smoking status and underlying disease, a moderate association between the influenza vaccine and severe laboratory-confirmed influenza-related illness was found in an epidemic season in which there was matching between the vaccine and circulating strains. Protection against complications, especially in older subjects and in those with underlying disease is postulated as one of the strengths of annual influenza vaccination. However, influenza vaccination is a pending issue in these groups, especially in pregnant women and obese people. To avoid suboptimal vaccination coverages, health professionals should recommend the seasonal influenza vaccination according to the annual instructions of the health authorities.

Automated parasitological diagnosis in clinical microbiology laboratories.

Although there is a low prevalence of parasitological infections in Europe, the diagnosis of intestinal parasites is still difficult and laborious for microbiology laboratories. Currently, antigen detection assays and molecular biology allow a more accurate diagnosis, but these techniques have limitations as they cannot detect all the possible parasites present in the samples. The objective of the study was to evaluate the accuracy and the usefulness of automated microscopy SediMAX2 (77 Elektronika, Budapest, Hungary) in the detection of parasitic infections from feces. A total of 197 formol-fixed stool samples were processed in parallel by wet mount examination and by SediMAX2. Sensitivities, specificities and predictive values were analyzed, reaching a sensitivity of 89.51% and a specificity of 98.15% and a very good positive predictive value (99.22%). SediMAX2 is a good tool for a reliable diagnosis of intestinal parasitic infections. The rapid processing and the flexibilty of storage of images analyzed make its incorporation into the day to day laboratory routine recommendable.

Characterization of Acute HCV Infection and Transmission Networks in People Who Currently Inject Drugs in Catalonia: Usefulness of Dried Blood Spots.

BACKGROUND AND AIMS: Accurate identification of recent HCV infections is critical for tracing the extent and mechanisms of ongoing transmission. We aimed to validate dried blood spot (DBS) samples for the assessment of Hepatitis C virus (HCV) genetic diversity and to determine epidemiological parameters including incidence, determinants of acute infection, and phylogenetic clustering in people who inject drugs (PWID). APPROACH AND RESULTS: HCV nonstructural protein 5B next-generation sequencing was performed from plasma and/or DBS in 220 viremic PWID from the HepCdetect II study. No significant differences were found in consensus sequences or Shannon entropy (SE) intrahost diversity estimate between paired plasma/DBS specimens. SE values were used to identify acute infections with 93.3% sensitivity (95% CI, 0.81-1.06) and 95.0% specificity (95% CI, 0.88-1.02) in a set of well-defined controls. An acute HCV infection (either primary infection or reinfection) was detected in 13.5% of viremic participants and was associated with age ≤30 years (OR, 8.09), injecting less than daily (OR, 4.35), ≤5 years of injected drug use (OR, 3.43), sharing cocaine snorting straws (OR, 2.89), and being unaware of their HCV status (OR, 3.62). Annualized HCV incidence was estimated between 31 and 59/100 person-years. On phylogenetic analysis, 46.8% of viremic cases were part of a transmission pair or cluster; age ≤30 years (OR, 6.16), acute infection (OR, 5.73), and infection with subtype 1a (OR, 4.78) were independently associated with this condition. CONCLUSIONS: The results obtained from plasma and DBS characterize PWID with acute infection and those involved in ongoing HCV transmission and allow estimating incidence from cross-sectional data. This information is critical for the design and assessment of targeted harm reduction programs and test-and-treat interventions and to facilitate monitoring of HCV elimination in this key population.

The hepatitis C care cascade among people who inject drugs accessing harm reduction services in Catalonia: Major gaps for migrants.

BACKGROUND: This study aimed to describe the HCV cascade of care among people who inject drugs (PWID) in Catalonia, as well as to compare the observed gaps in care between Spanish-born and migrant PWID. METHODS: A cross-sectional study of PWID (N = 410) attending four harm reduction services (HRS) was performed in 2016-17 (HepCdetect II Study). Participants were tested for both HCV antibodies (rapid testing) and RNA (from dried blood spot samples). The HCV care cascade was estimated from HCV testing results combined with self-reported data on previous testing, diagnosis and treatment collected through a questionnaire. Logistic regressions were used to test for an association between migration status and the proportions observed in each step of the HCV care cascade adjusting for age, sex, years of injection, homelessness, and treatment for drug dependence. RESULTS: Overall, 85.4% were men and 28.0% were migrants. Among Spanish-born (n = 295) and migrant (n = 115) PWID participants in the study, 96.6% vs. 88.6% had previously been HCV screened (AOR=3.11; 95% CI: 1.11-8.65), 79.3% vs. 80.9% were antibody positive, and 70.7% vs. 67.6% were HCV-RNA positive or cured with treatment; among the latter, 36.6% vs. 18.2% had started treatment (AOR=2.41; 95% CI: 1.09-5.34), and 20.6% vs. 9.1% had been cured by treatment, respectively. Unawareness of having hepatitis C was more common among migrants than Spanish-born PWID (46.0% and 31.5%, respectively; p<0.05). CONCLUSION: This study estimates the HCV care cascade among Spanish-born and migrant PWID in Catalonia for the very first time, and highlights a higher attrition of migrant PWID in all HCV care cascade stages. The observed limited linkage to care and treatment by PWID that attend the HRS network warrants future implementation of decentralized diagnosis and antiviral treatment. Strategies focusing on migrants by increasing HCV screening coverage and treatment access will be especially relevant in our setting.

Trichophyton erinacei: an emergent pathogen of pediatric dermatophytosis.

BACKGROUND: Dermatophytoses in children are common pathologies worldwide caused mainly by Trichophyton rubrum. However, due to the globalization and the atypical pets that people nowadays own, some zoonotic species are also involved in these lesions. CASE REPORT: We present two cases of tinea faciei caused by the zoonotic mould Trichophyton erinacei in two children that owned a guinea pig and a hedgehog, respectively. Mycological diagnosis was performed inoculating skin scales on Sabouraud-glucose agar plates supplemented with chloramphenicol, with and without gentamicin, and on Sabouraud-glucose agar tubes, with and without cycloheximide. Microscopical examination in both cases and ITS region sequencing to confirm the identification (performed in one of them) were compatible with T. erinacei. Multiple treatments like corticosteroids and antibiotics were prescribed prior to the accurate diagnosis. Finally, both patients received topical and oral terbinafine, respectively, the lesions being resolved entirely. CONCLUSIONS: Zoonotic fungi must be considered in the diagnosis of skin lesions. An accurate medical record, with a guided anamnesis about possible risk factors and an ongoing and open dialogue between health professionals, are essential to improve both the management of these exotic and zoophilic dermatophytoses.

Macrolide resistance and molecular typing of Mycoplasma pneumoniae infections during a 4 year period in Spain.

BACKGROUND: Mycoplasma pneumoniae (MP) causes community-acquired pneumonia affecting mainly children, and tends to produce cyclic outbreaks. The widespread use of macrolides is increasing resistance rates to these antibiotics. Molecular tools can help in diagnosis, typing and resistance detection, leading to better patient management. OBJECTIVES: To assess the MP genotypes and resistance pattern circulating in our area while comparing serological and molecular diagnosis of MP. METHODS: Molecular and serological diagnosis of MP was performed in 821 samples collected in Badalona (Barcelona, Spain) from 2013 to 2017. Multiple locus variable number tandem repeat analysis (MLVA) and macrolide resistance detection by pyrosequencing were performed in those cases positive by PCR. Presence of respiratory viruses and relevant clinical data were also recorded. RESULTS: MP was detected in 16.8% of cases by PCR, with an overall agreement with serology of 76%. Eleven different MLVA types were identified, with 4-5-7-2 (50.1%) and 3-5-6-2 (29.2%) being the most abundant, with the latter showing a seasonal increase during the study. A total of 8% of the strains harboured a point substitution associated with macrolide resistance, corresponding mainly to an A2063G 23S rRNA mutation and directly related to previous macrolide therapy. Analysis of respiratory viruses showed viral coinfections in most cases. CONCLUSIONS: Serological and molecular tools combined could improve MP diagnosis and the analysis of its infection patterns. Macrolide resistance is associated with previous therapy. Given that MP pneumonia usually resolves spontaneously, it should be reconsidered whether antibiotic treatment is suitable for all cases.

Pooling of urine samples for molecular detection of Chlamydia trachomatis, Neisseria gonorrhoeae and Mycoplasma genitalium as a screening strategy among young adults in Catalonia.

INTRODUCTION: Bacterial sexually transmitted infections (STIs) have an important impact on reproductive health, highlighting the increase in Chlamydia trachomatis infection rates among young people. To reduce the costs of STI detection, the pooling strategy is beneficial for high-throughput tests in low-prevalence populations using non-invasive samples. OBJECTIVES: (1) To describe the performance of a 7-STI PCR assay using the pooling of three urine samples to detect C. trachomatis, Neisseria gonorrhoeae and Mycoplasma genitalium; (2) to estimate the cost saving of the pooling strategy; (3) to describe the prevalence, risk factors and coinfections of C. trachomatis, N. gonorrhoeae and M. genitalium in young people ≤25 years in Catalonia. METHODS: cross-sectional prevalence study conducted in 2016 among young people ≤25 years of age seen in sexual and reproductive health centres throughout Catalonia from pools of three urine samples. A standardized questionnaire was used to collect clinical-epidemiological and behavioural variables. RESULTS: 1032 young people were tested. The prevalence of C. trachomatis, N. gonorrhoeae and M. genitalium was 8.5%, 0.6% and 3.5%, respectively. The pooling strategy provided a 33% savings in reagent costs. CONCLUSIONS: The pooling strategy implemented for epidemiological studies in our context provides a savings that has an impact on the viability of STI detection programmes. In the same way, this study shows that C. trachomatis prevalence continues to increase in this population and, for the first time in Catalonia, the prevalence of M. genitalium in young people is shown.

Utility of a one-step screening and diagnosis strategy for viremic HCV infection among people who inject drugs in Catalonia.

BACKGROUND: In Catalonia (Spain), people who inject drugs (PWID) face numerous barriers to access to mainstream healthcare services for hepatitis C confirmatory diagnosis and treatment, so simplified testing strategies for viremic infection are urgently needed. Among PWID attending harm-reduction services in Catalonia, we aimed (i) to assess the utility of an in-house HCV-RNA detection assay on dried blood spots (DBS) as a one-step screening and confirmatory diagnosis strategy for hepatitis C, (ii) to estimate the prevalence of viremic HCV infection, and (iii) to identify factors associated with unawareness of viremic infection. METHODS: A cross-sectional study of current PWID (N â€¯= 410) was performed in four harm-reduction services. All participants underwent HCV antibody point-of-care testing and parallel DBS collection for centralized RNA testing. An epidemiological questionnaire was administered. Paired EDTA-plasma samples were additionally collected for HCV viral load testing in 300 participants. RESULTS: HCV-RNA testing from DBS was feasible and showed 97.2% sensitivity and 100% specificity for viral loads >3000 IU/mL in real-life conditions. No significant differences in the performance when detecting viremic infections were observed between this one-step testing strategy vs. the conventional two-step algorithm involving venepuncture. Overall HCV seroprevalence was 79.8%, and prevalence of viremic infection was 58.5%. Importantly, 35.8% of viremic HCV participants were unaware of their status, and no specific socio-demographic or bio-behavioral factors independently associated with unawareness of viremic infection were identified. Among participants reporting a past or current HCV infection, 29.0% stated having received HCV antiviral treatment. CONCLUSION: The high viremic HCV infection burden among PWID attending HRS, estimated for the first time in Catalonia, together with the low levels of awareness of viremic status and access to treatment, suggest that scaling up this one-step screening and diagnosis strategy to the network of harm-reduction services would help to achieve HCV elimination targets set by the World Health Organization.

Epidemiology of dermatophytic infections between 2008 and 2017 in Barcelona, Spain.

OBJECTIVE: The aim of this study was to evaluate the epidemiological profile of dermatophytoses from 2008 to 2017 in the area of "Barcelonès Nord", located in north-eastern Spain. METHODS: From 2008 to 2017, 13,419 specimens obtained from patients with suspected superficial mycosis were subjected to direct microscopy and culture. Clinical and sociodemographic data were recorded. Proportions were compared using Chi-square and Fisher's exact tests. A logistic regression model was used for multivariate analysis. RESULTS: Trichophyton rubrum was the most frequently isolated fungus (76.1%), followed by Trichophyton mentagrophytes/Trichophyton interdigitale (11.9%) and Microsporum canis (2.9%). Among the population over 15 years of age, tinea unguium pedum (40.4%) and tinea corporis (29.1%) were the predominant dermatophyte infections. Tinea capitis was mostly prevalent (53.6%) among patients up to 15 years of age, followed by tinea corporis (21.4%). We observed an increase in non-endemic anthropophilic dermatophytes (Trichophyton soudanense, Microsporum audouinii and Trichophyton violaceum) in the last few years. These species were associated with the population up to 15 years of age (p<0.001), having tinea capitis (p=0.0017) and being of African/Hindustani origin (p<0.001). CONCLUSIONS: We confirmed the spread of T. rubrum as the predominant dermatophyte in our area and reported an increase in non-endemic anthropophilic dermatophytes in the last few years, especially in the African and Hindustani population up to 15 years of age.

Diagnosis of soil-transmitted helminth infections. An unsolved problemin the omics era. / Diagnóstico de las infecciones por geohelmintos. Un problema sin resolver en la era de las ómicas.

Infections caused by Strongyloides stercoralis and other soil-transmitted worms such as hookworms (Necator americanus and Ancylostoma duodenale) represent a major problem worldwide, especially in developing areas. They are difficult to suspect clinically since they produce non-specific and often overlapping signs and symptoms. Likewise, their long prepatent periods hamper the detection of parasitic structures. Microscopic diagnosis is still the most commonly used tool in healthcare laboratories but it is still far from being the ideal technique to detect these infections due to its low sensitivity. In addition, these nematodes have strong morphologic similarities and consequently microbiological diagnosis remains a challenge. Serology has made progress in the diagnosis of S. stercoralis infection but this option is not yet available for hookworms. Molecular biology techniques have been shown to slightly increase this lack of sensitivity, but as with other parasitic infections, they are not currently available for use in clinical microbiology laboratories. Supplement information: This article is part of a supplement entitled «SEIMC External Quality Control Programme. Year 2016¼, which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A. © 2019 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosasy Microbiología Clínica. All rights reserved.

Comparative Evaluation of Indirect Immunofluorescence and NS-1-Based ELISA to Determine Zika Virus-Specific IgM.

Differential diagnosis of the Zika virus (ZIKV) is hampered by cross-reactivity with other flaviviruses, mainly dengue viruses. The aim of this study was to compare two commercial methods for detecting ZIKV immunoglobulin M (IgM), an indirect immunofluorescence (IIF) and an enzyme immunoassay (ELISA), using the non-structural (NS) 1 protein as an antigen, both from EuroImmun, Germany. In total, 255 serum samples were analyzed, 203 of which showed laboratory markers of ZIKV infections (PCR-positive in serum and/or in urine and/or positive or indeterminate specific IgM). When tested with IIF, 163 samples were IgM-positive, while 13 samples were indeterminate and 78 were negative. When IIF-positive samples were tested using ELISA, we found 61 positive results, 14 indeterminate results, and 88 negative results. Among the indeterminate cases tested with IIF, ELISA analysis found two positive, two indeterminate, and nine negative results. Finally, 74 of the 78 IIF-negative samples proved also to be negative using ELISA. For the calculations, all indeterminate results were considered to be positive. The agreement, sensitivity, and specificity between ELISA and IIF were 60.2%, 44.9%, and 94.9%, respectively. Overall, 101 samples showed discrepant results; these samples were finally classified on the basis of other ZIKV diagnostic approaches (PCR-positive in serum and/or in urine, IgG determinations using IIF or ELISA, and ZIKV Plaque Reduction Neutralization test-positive), when available. A final classification of 228 samples was possible; 126 of them were positive and 102 were negative. The corresponding values of agreement, sensitivity, and specificity of IIF were 86.0%, 96.8%, and 72.5%, respectively. The corresponding figures for ELISA were 81.1%, 65.9%, and 100%, respectively. The ELISA and IIF methods are both adequate approaches for detecting ZIKV-specific IgM. However, considering their respective weaknesses (low sensitivity in ELISA and low specificity in IIF), serological results must be considered jointly with other laboratory results.

Impact of intensification with raltegravir on HIV-1-infected individuals receiving monotherapy with boosted PIs.

Background: Monotherapy with ritonavir-boosted PIs (PI/r) has been used to simplify treatment of HIV-1-infected patients. In previous studies raltegravir intensification evidenced ongoing viral replication and reduced T cell activation, preferentially in subjects receiving PI-based triple ART. However, data about low-level viral replication and its consequences in patients receiving PI/r monotherapy are scarce. Methods: We evaluated the impact of 24 weeks of intensification with raltegravir on markers of viral persistence, cellular immune activation and inflammation biomarkers in 33 patients receiving maintenance PI/r monotherapy with darunavir or lopinavir boosted with ritonavir. ClinicalTrials.gov identifier: NCT01480713. Results: The addition of raltegravir to PI/r monotherapy resulted in a transient increase in 2-LTR (long-terminal repeat) circles in a significant proportion of participants, along with decreases in CD8+ T cell activation levels and a temporary increase in the expression of the exhaustion marker CTLA-4 in peripheral T lymphocytes. Intensification with raltegravir also reduced the number of samples with intermediate levels of residual viraemia (10-60 HIV-1 RNA copies/mL) compared with samples taken during PI/r monotherapy. However, there were no changes in cell-associated HIV-1 DNA in peripheral CD4+ T cells or soluble inflammatory biomarkers (CD14, IP-10, IL-6, C-reactive protein and D-dimer). Conclusions: Intensification of PI/r monotherapy with raltegravir revealed persistent low-level viral replication and reduced residual viraemia in some patients during long-term PI/r monotherapy. The concomitant change in T cell phenotype suggests an association between active viral production and T cell activation. These results contribute to understanding the lower efficacy rates of PI/r monotherapies compared with triple therapies in clinical trials.

Postinfectious glomerulonephritis secondary to Erythrovirus B19 (Parvovirus B19): case report and review of the literature.

A previously healthy 32-yearold woman developed arterial hypertension, proteinuria, and hematuria (nephritic syndrome) with normal renal function and was diagnosed with post-infectious glomerulonephritis secondary to parvovirus B19 infection. The renal biopsy showed endocapillary glomerulonephritis, with positive IgG, C3, and C1q immunoreactivity in the capillary walls and ultrastructural evidence of subendothelial deposits. The diagnosis of parvovirus B19 infection was confirmed by IgG/IgM serological positivity and parvovirus DNA demonstration in both peripheral blood and kidney tissue. Glomerular involvement improved spontaneously. To be noted are the atypical signs and symptoms of our patient who, unlike previously reported cases, failed to show fever, skin rash, or affected relatives.

Consumption of systemic antifungal agents among acute care hospitals in Catalonia (Spain), 2008-2013.

Objective To know the patterns and consumption trends (2008-2013) of antifungal agents for systemic use in 52 acute care hospitals affiliated to VINCat Program in Catalonia (Spain). Methods Consumption was calculated in defined daily doses (DDD)/100 patient-days and analyzed according to hospital size and complexity and clinical departments. Results Antifungal consumption was higher in intensive care units (ICU) (14.79) than in medical (3.08) and surgical departments (1.19). Fluconazole was the most consumed agent in all type of hospitals and departments. Overall antifungal consumption increased by 20.5%during the study period (p = 0.066); a significant upward trend was observed in the consumption of both azoles and echinocandins. In ICUs, antifungal consumption increased by 12.4% (p = 0.019). Conclusions The study showed a sustained increase in the overall consumption of systemic antifungals in a large number of acute care hospitals of different characteristics in Catalonia. In ICUs there was a trend towards the substitution of older agents by the new ones.

Usefulness of a novel multiplex real-time PCR assay for the diagnosis of sexually-transmitted infections.

INTRODUCTION: Sexually transmitted infections (STI) are currently on the increase worldwide. New molecular tools have been developed in the past few years in order to improve their diagnosis. An evaluation was carried out using a new commercially available real-time PCR assay, Anyplex™ II STI-7 (Seegene, Seoul, Korea), which detects seven major pathogens in a single reaction - Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum, and Ureaplasma parvum - and compared with conventional methods performed in our laboratory. MATERIALS AND METHODS: Two different populations were included, and 267 specimens from different sites of infection (urines, endocervical swabs, rectal swabs, vaginal swabs, urethral swabs and one inguinal adenopathy) were processed for both methods. RESULTS: The parameters of clinical performance were calculated for C. trachomatis, N. gonorrhoeae, and T. vaginalis, and the assay achieved sensitivities (SE) from 93.94% to 100%, and specificities (SP) from 96.55% to 100%, with negative predictive values (NPV) from 93.33% to 98.85%, and positive predictive values (PPV) from 96.88% to 100%, with a very good agreement (kappa index from 0.88 to 1). CONCLUSIONS: Anyplex™ II STI-7 is a good tool for the reliable diagnosis of STI. Its ease of use and processing allows it to be incorporated into the day to day laboratory work.

Evaluation of the Vitros Syphilis TPA chemiluminescence immunoassay as a first-line method for reverse syphilis screening.

We report here the results of the diagnostic performances of Vitros Syphilis TPA (a chemiluminescence treponemal assay) compared with those of two treponemal enzyme immunoassays and of traditional versus reverse syphilis algorithms. Ease of use, automation, and high throughput make the Vitros Syphilis TPA assay a good choice for syphilis screening in high-volume laboratories.