Diagnostic accuracy of commercially available serological tests for the detection of measles and rubella viruses: a systematic review and meta-analysis.

Measles and rubella serological diagnoses are done by IgM detection. The World Health Organization Global Measles and Rubella Laboratory Network previously endorsed Siemens Enzygnost enzyme-linked immunosorbant assay kits, which have been discontinued. A recommended replacement has not been determined. We aimed to search for suitable replacements by conducting a systematic review and meta-analysis of IgM detection methods that are currently available for measles and rubella. A systematic literature search was performed in Medline, Embase, Global Health, Cochrane Central, and Scopus on March 22 and on 27 September 2023. Studies reporting measles and/or rubella IgM detection with terms around diagnostic accuracy were included. Risk of bias was assessed using QUADAS tools. Meta-DiSc and R were used for statistical analysis. Clinical samples totalling 5,579 from 28 index tests were included in the measles meta-analysis. Sensitivity and specificity of the individual measles studies ranged from 0.50 to 1.00 and 0.53 to 1.00, respectively. Pooled sensitivity and specificity of all measles IgM detection methods were 0.94 (CI: 0.90-0.97) and 0.94 (CI: 0.91-0.97), respectively. Clinical samples totalling 4,983 from 15 index tests were included in the rubella meta-analysis. Sensitivity and specificity of the individual rubella studies ranged from 0.78 to 1.00 and 0.52 to 1.00, respectively. Pooled sensitivity and specificity of all rubella IgM detection methods were 0.97 (CI: 0.93-0.98) and 0.96 (CI: 0.93-0.98), respectively. Although more studies would be ideal, our results may provide valuable information when selecting IgM detection methods for measles and/or rubella.

Cutaneous granulomas associated with rubella virus: A clinical review.

Since the initial identification of vaccine-derived rubella virus (RuV) in the cutaneous granulomas of pediatric patients with inborn errors of immunity in 2014, more than 80 cases of RuV granulomas have been reported implicating both vaccine-derived and wild type RuV. Previously thought to arise exclusively in patients with significant immunocompromise, the identification of RuV granulomas in clinically immunocompetent patients adds nuance to our understanding of the interplay between host environment, immune dysregulation, and RuV granuloma formation. This review summarizes the literature on RuV granulomas including clinical and histopathologic features, proposed pathomechanisms supporting granuloma development, and potential therapeutic options. There is no standardized algorithm to guide the workup and diagnosis of suspected RuV granulomas. We highlight the importance of contributing RuV granuloma cases to ongoing Centers for Disease Control and Prevention surveillance efforts to monitor wild type and vaccine-derived RuV transmission. Studies advancing our understanding of RuV granulomas may provide insights into the role of viral infectious agents in granulomatous disease pathogenesis and guide the development of improved therapeutic options.

Fundus imaging features of congenital rubella retinopathy.

PURPOSE: To evaluate the clinical characteristics of congenital rubella retinopathy (CRR) with modern fundus imaging. METHODS: Single-center case series. Eleven patients (2005-2020) at the Emory Eye Center with known or presumed CRR. Trained image readers reviewed fundus imaging (color fundus photography, widefield pseudocolor imaging, near-infrared reflectance imaging, autofluorescence imaging, and spectral-domain optical coherence tomography) for pre-specified features suggestive of CRR. RESULTS: Eleven patients with confirmed (63.6%) or presumed (36.3%) CRR were identified. All were female with median (range) age of 53 (35-67) years. Six (54.5%) were born during the 1964-1965 United States rubella epidemic. All had congenital hearing loss. Two (18.2%) had a congenital heart defect. Eleven (50.0%) eyes had salt-and-pepper retinal pigmentary changes. Twenty-two eyes (100.0%) had irregularly distributed regions of speckled hypoautofluorescence. One eye (4.5%) had a presumed macular neovascularization. CONCLUSION: Modern fundus imaging demonstrates characteristic features of CRR, even when pigmentary changes are not readily apparent on examination. Widefield autofluorescence findings of irregularly distributed speckled hypoautofluorescence are particularly revealing. This series of newly diagnosed adults with CRR may represent the milder end of the phenotypic spectrum of this condition, highlighting imaging findings that may aid in diagnostically challenging cases of CRR.

Rubella.

Rubella is an acute illness caused by rubella virus and characterised by fever and rash. Although rubella is a clinically mild illness, primary rubella virus infection in early pregnancy can result in congenital rubella syndrome, which has serious medical and public health consequences. WHO estimates that approximately 100 000 congenital rubella syndrome cases occur per year. Rubella virus is transmitted through respiratory droplets and direct contact. 25-50% of people infected with rubella virus are asymptomatic. Clinical disease often results in mild, self-limited illness characterised by fever, a generalised erythematous maculopapular rash, and lymphadenopathy. Complications include arthralgia, arthritis, thrombocytopenic purpura, and encephalitis. Common presenting signs and symptoms of congenital rubella syndrome include cataracts, sensorineural hearing impairment, congenital heart disease, jaundice, purpura, hepatosplenomegaly, and microcephaly. Rubella and congenital rubella syndrome can be prevented by rubella-containing vaccines, which are commonly administered in combination with measles vaccine. Although global rubella vaccine coverage reached only 70% in 2020 global rubella eradiation remains an ambitious but achievable goal.

Contribution of parvovirus B19 in suspected cases of measles/rubella in Osaka, Japan, between 2011 and 2021.

Erythema infectiosum, caused by human parvovirus B19 (B19V), is difficult to diagnose by its clinical symptoms and is often misdiagnosed as measles or rubella. Timely confirmation of measles/rubella or other viral etiologies via laboratory tests can provide an accurate picture of the infection status, which can appropriate response. The purpose of this study was to determine the contribution of B19V as an etiological agent for fever-rash in suspected cases of measles and rubella in Osaka Prefecture between 2011 and 2021. Of 1356 suspected cases, 167 were confirmed with measles and 166 with rubella using nucleic acid testing (NAT). Of the remaining 1023 cases, 970 from which blood specimens could be obtained were screened by real-time polymerase chain reaction for B19V, from which 136 (14%) tested positive. Of the positives cases, 21% were young children (9 years and younger), while 64% were adults (20 years and older). Phylogenetic tree analysis showed that 93 samples belonged to genotype 1a. The importance of B19V in the etiology of fever-rash illness was revealed in this study. The importance of laboratory diagnosis by NAT in maintaining the status of measles elimination and to eliminate rubella was reaffirmed.

Differential diagnosis of fever and rash cases negative for measles and rubella to complement surveillance activities.

In the quest to eliminate measles virus (MV) and rubella virus (Ruv), every suspected case must be properly identified and diagnosed. Since 2017, in Milan (Italy), a total of 978 measles and rubella suspected cases (fever and rash) were investigated and 310 were not laboratory confirmed (discarded cases). To improve surveillance activities, we investigated the presence in discarded cases of 8 other viral pathogens commonly associated with rash: human herpesvirus 6 (HHV-6) and 7 (HHV-7), parvovirus B19 (B19V), enterovirus (EV), Epstein-Barr virus (EBV), human adenovirus (HAdV), cytomegalovirus (HCMV), and SARS-CoV-2. Differential diagnosis was carried out on 289 discarded cases by multiplex real-time PCR assays. At least one pathogen was detected in 188 cases (65.1%) with HHV-7 being the most frequently detected virus. No difference in the number of detected infections overtime was observed and infections were identified in all age groups. As expected, most HHV-6, EV, HAdV, and HCMV-positive cases were found in children aged 0-4 years and HHV-7 was most frequent in the 15-39 age group. In light of the World Health Organization measles elimination goal, the introduction of laboratory methods for differential diagnosis is required for the final classification of clinically compatible cases. The used screening panel allowed us to increase the percentage of virus-positive cases to 87.5%, allowing us to clarify viral involvement and epidemiology, improve diagnosis, and strengthen surveillance activities. As all investigated pathogens were detected, this diagnostic panel was a suitable tool to complement MV and RuV surveillance activities.

Rubella virus-associated uveitis at a tertiary care hospital in Germany between 2013 and 2019.

Uveitis is a process of intraocular inflammation that may involve different sections of the uveal tract. Apart from systemic or localized immune-mediated diseases, infections are key players in the etiology of uveitis and entail different treatment strategies. Rubella virus (RuV) is a recognized causative agent for the development of Fuchs uveitis, representing a major cause of virus-associated intraocular inflammation. A cohort of 159 patients diagnosed with different forms of uveitis between 2013 and 2019 was subjected to diagnostic antibody testing of the aqueous or vitreous humor. The diagnostic panel included RuV, cytomegalovirus, herpes simplex virus, varicella-zoster virus, and toxoplasmosis. Within this cohort, 38 RuV-associated uveitis (RAU) patients were identified based on a pathologic Goldman-Witmer coefficient indicative of an underlying RuV infection. With a mean age of 45.9 years, the RAU patients were younger than the non-RAU patients (56.3, p < 0.001). The evaluation of clinical parameters revealed a predominance of anterior uveitis and late sequalae such as cataract and glaucoma among the RAU patients. In 15 of the patients a history of prior RuV infections could be confirmed. The study underlines the importance of long-term surveillance of RuV associated diseases that originate from infections before the introduction of RuV vaccination programs.

Ocular Involvement in Congenital Infections - TORCH. / Augenbeteiligung bei kongenitalen Infektionen ­ TORCH.

This review summarises the ophthalmological findings in congenital infections. Intrauterine infections are an important cause of childhood blindness. The most common infections are grouped under the acronym TORCH, which stands for Toxoplasma gondii, others, rubella, CMV, and herpes simplex. Overall, these infections are not very common in first-world countries during pregnancy, but are of particular importance because of the threat to vision. Diagnosis of infection or reactivation is a gynaecological challenge. However, ophthalmological examination of newborns can be appropriately targeted if the causative agent is known. The most important therapeutic agents used in the newborn are summarised.

Evaluation of Diagnostic Accuracy of Eight Commercial Assays for the Detection of Rubella Virus-Specific IgM Antibodies.

Rubella and congenital rubella syndrome are caused by the rubella virus and are preventable through vaccination, making disease eradication possible. Monitoring of progress toward global eradication and local elimination requires high-quality, sensitive disease surveillance that includes laboratory confirmation of cases. Previous evaluations of anti-rubella IgM detection methods resulted in the broad adoption of the Enzygnost (most recently manufactured by Siemens) enzyme-linked immunosorbent assay (ELISA) kits within WHO's global measles and rubella laboratory network, but they have been discontinued. This study evaluated seven comparable ELISAs from six manufacturers (Trinity Biotech, Euroimmun, Clin-Tech, NovaTec and Virion\Serion) as well as one automated chemiluminescent assay (CLIA) from DiaSorin. These assays include three IgM capture assays and five indirect ELISAs. A panel of 238 sera was used for the evaluation that included 38 archival rubella IgM-positive sera and 200 sera collected from patients with symptomatically similar diseases, such as measles, dengue, parvovirus B19 infection, and roseola. With this panel of sera, the sensitivity of the methods ranged from 63.2% to 100% and the specificity from 80.0% to 99.5%. No single method had both sensitivity and specificity of >90%, unless sera with equivocal results were considered presumptively positive. Some assays, particularly the Serion ELISA, had a large number of false positives with parvovirus B19 IgM-positive sera as well as sera from confirmed measles cases. The performance characteristics identified in this evaluation serve as a reminder to not rely solely on rubella IgM results for case confirmation in elimination settings.

Expansion of the measles and rubella laboratory network, India.

Objective: To expand the measles and rubella laboratory network of India by integrating new laboratories. Methods: In collaboration with the World Health Organization (WHO), the Indian government developed a 10-step scheme to systematically expand the number of laboratories performing serological and molecular testing for measles and rubella. The Indian Council of Medical Research and WHO identified suitable laboratories based on their geographical location, willingness, preparedness, past performance and adherence to national quality control and quality assurance mechanisms. The 10-step scheme was initiated with training on measles and rubella diagnostic assays followed by testing of both measles and rubella serology and molecular unknown panels, cross-verification with reference laboratories and ended with WHO on-site accreditation. Findings: After extensive training, technical support, funding and monitoring, all six selected laboratories attained passing scores of 90.0% or more in serological and molecular proficiency testing of measles and rubella. Since 2018, the laboratories are a part of the measles and rubella network of India. Within 12 months of initiation of independent reporting, the six laboratories have tested 2287 serum samples and 701 throat or nasopharyngeal swabs or urine samples. Conclusion: The process led to strengthening and expansion of the network. This proficient laboratory network has helped India in scaling up serological and molecular testing of measles and rubella while ensuring high quality testing. The collaborative model developed by the Indian government with WHO can be implemented by other countries for expanding laboratory networks for surveillance of measles and rubella as well as other infectious diseases.

Design of a chimaeric antigen and its use in the detection of IgG antibodies against rubella virus.

BACKGROUND: Rubella virus (RV) is the causative agent of rubella or German measles. Although most infections cause only mild self-limited measles-like illness, the infection in pregnant women can cause severe foetal malformation or even miscarriage, especially in the first 3 months of pregnancy. Therefore, it is of great practical significance to establish a simple and sensitive RV detection method. METHODS: The partial epitopes of the E1 and E2 proteins from Rubella Virus were selected as the target sites, the sequence of the selected antigenic sites of the E1 and E2 were linked by a linker. The expression plasmid P6T was constructed by inserting the gene into PET-32A + with a histidine Tag. The P6 protein was induced and expressed in Escherichia coli L21 (DE3) and purified by nickel column affinity. The protein P6 antigen was identified by Western blotting analysis, and an anti-P6 antibody ELISA was established to test known serum samples to evaluate the capability of this method. RESULTS: After purification, the concentration and purity of the protein P6 were 0.283 mg/mL and more than 80%, respectively. Western blotting analysis showed that the protein P6 could react with rubella virus positive serum. By ELISA, 36 negative sera and 58 positive sera were detected. The coincidence rate, specificity and sensitivity of the ELISA were 86.2%, 88.89% and 84.48%, respectively. The P6 ELISA with a kappa coefficient of 0.715, P < 0.05, indicated excellent consistency. CONCLUSIONS: The protein P6 with excellent antigenicity obtained from prokaryotic expression followed by chromatography purification could prove useful for early diagnosis of RV infection.

Phylogenetic analysis of congenital rubella virus from Indonesia: a case report.

BACKGROUND: Rubella is a common inherited infection resulting in congenital cataracts and a significant cause of permanent vision loss in developing countries. In 2016, Indonesia had the highest number of congenital rubella syndrome (CRS) cases globally. Here, we report the first genotype of the rubella virus extracted from the eye lens from a child with congenital cataracts due to CRS. CASE PRESENTATION: A female neonate was delivered by an elective caesarean delivery with normal birth weight at term from a 24-year-old mother in the rural setting. The baby presented with bilateral congenital cataracts, small-moderate secundum atrial septal defect, severe supravalvular pulmonary stenosis, and profound bilateral hearing loss. She also had microcephaly and splenomegaly. The patient's serology showed persistent positive IgG for rubella virus at the age of four years and four months. Following extraction during cataract surgery, viral detection of the lenses identified the presence of rubella. Phylogenetic analysis confirmed that the virus was grouped into genotype 1E. CONCLUSIONS: Our study reports the first phylogenetic analysis of the rubella virus extracted from the eye lens of a child with CRS in Indonesia. The detection of the rubella virus from eye lenses is remarkably promising. Our findings also emphasize the importance of molecular epidemiology in tracking the origin of rubella infection toward achieving virus eradication.

The Screening of Rubella Virus, Cytomegalovirus, Hepatitis B Virus, and Toxoplasma gondii Antibodies in Prepregnancy and Reproductive-Age Women in Tabriz, Iran.

OBJECTIVES: The organisms of Toxoplasma gondii, Rubella virus, Cytomegalovirus, and Herpes simplex virus as an acronym of TORCH are major pathogens in prepregnancy and reproductive-age women. These microorganisms are considered a serious problem and cause 2-3% of all birth defects in the fetus. Our study was aimed at screening the seroprevalence of TORCH antibodies among prepregnancy and reproductive-age women in Tabriz, Iran. Design and Setting. This study was carried out in 2726 prepregnancy and reproductive-age women, who were referred to the laboratory for prenatal TORCH screening. To detect the presence of IgG, IgM antibodies and Hepatitis B surface antigen against these microorganisms were carried out using a chemiluminescence immunoassay analyzer (CLIA). RESULTS: In the current study, the rates of anti-Toxoplasma gondii IgG, anti-Rubella virus IgG, and anti-Cytomegalovirus IgG were found in 722 cases (26.5%), 2579 cases (94.6%0), and 2718 cases (99.7%), respectively. Moreover, the rates of anti-Toxoplasma gondii IgM, anti-Rubella virus IgM, and anti-Cytomegalovirus IgM were discovered in 10 cases (0.4%), 13 cases (0.5%), and 16 cases (0.6%), respectively. The Hepatitis B surface antigen was found in 32 cases (1.2%). The dissemination of positive TORCH in various ages was different (P < 0.05). CONCLUSIONS: In our study, the seroprevalence of acute TORCH infections was relatively low. Due to the probability of vertical transmission to the fetus during pregnancy and the unpleasant complication of these pathogens, it is essential to be screened for detection of specific IgG and IgM antibodies in reproductive ages.

Development of a Measles and Rubella Multiplex Bead Serological Assay for Assessing Population Immunity.

Serosurveys are important tools for estimating population immunity and providing immunization activity guidance. The measles and rubella multiplex bead assay (MBA) offers multiple advantages over standard serological assays and was validated by comparison with the enzyme-linked immunosorbent assay (ELISA) and the measles plaque reduction neutralization (PRN) assay. Results from a laboratory-produced purified measles virus whole-virus antigen MBA (MeV WVAL) correlated better with ELISA and PRN than results from the baculovirus-expressed measles nucleoprotein (N) MBA. Therefore, a commercially produced whole-virus antigen (MeV WVAC) was evaluated. Serum IgG antibody concentrations correlated significantly with a strong linear relationship between the MeV WVAC and MeV WVAL MBAs (R = 0.962 and R2 = 0.926). IgG concentrations from the MeV WVAC MBA showed strong correlation with PRN titers (R = 0.846), with a linear relationship comparable to values obtained with the MeV WVAL MBA and PRN assay (R2 = 0.716 and R2 = 0.768, respectively). Receiver operating characteristic (ROC) curve analysis of the MeV WVAC using PRN titer as the comparator resulted in a seroprotection cutoff of 153 mIU/ml, similar to the established correlate of protection of 120 mIU/ml, with a sensitivity of 98% and a specificity of 83%. IgG concentrations correlated strongly between the rubella WVA MBA and ELISA (R = 0.959 and R2 = 0.919). ROC analysis of the rubella MBA using ELISA as the comparator yielded a cutoff of 9.36 IU/ml, similar to the accepted cutoff of 10 IU/ml for seroprotection, with a sensitivity of 99% and a specificity of 100%. These results support use of the MBA for multiantigen serosurveys assessing measles and rubella population immunity.

The period from prodromal fever onset to rash onset in laboratory-confirmed rubella cases: a cross-sectional study.

BACKGROUND: In resource-limited settings, where rubella is endemic, it is difficult to determine which sporadic case should be tested for rubella. The study aimed to provide useful evidence to help screen rubella cases for real-time reverse transcriptase-polymerase chain reaction (RT-PCR) examination for rubella in resource-limited settings. METHOD: Suspected rubella patients identified by a physician and brought to the notice of the Ryugasaki public health center or the Tsuchiura public health center were enrolled from April 2018 through December 2019. The inclusion criterion was a confirmed rubella diagnosis based on laboratory tests. We studied the distribution of the time from the onset of fever until the onset of rash. RESULTS: The study included 86 cases with simultaneous presentation of fever and rash. Twenty-nine cases had confirmed rubella based on the laboratory diagnosis. Among these, the time from the onset of fever until the onset of rash was limited to - 1 day to 2 days. The number of rubella cases was the highest when the onset of rash was on the following day of the onset of fever. Of the 78 patients who underwent the RT-PCR test, 48% tested positive for rubella among those with a time from the onset of fever to the onset of rash between - 1 day and 2 days (22 out of 46, 95% confidence interval 34-62%); no positive results (0 out of 30, 95% confidence interval - 14%) were seen in patients with a time from fever to rash onset ≥3 days. CONCLUSION: The period from the onset of fever to the onset of rash was limited to - 1 day to 2 days among confirmed rubella patients. If the period from onset of fever to the onset of rash was ≥3 days for a patient, the likelihood of rubella was low.

Prediction of probability of rubella based on eye outcomes (PORBEO Nomogram)-a cross-sectional sentinel surveillance of 1134 infants.

INTRODUCTION: Rubella is an important infectious, vaccine-preventable etiology of congenital defects. The aim of the study was to develop a prediction nomogram to assess the probability of an infant being at risk for congenital rubella based on demographics and ophthalmological findings. METHODS: This was a cross-sectional sentinel surveillance study conducted at 5 centers spanning pan-India and involved 1134 infants. The diagnosis of rubella was made using standard guidelines. For the construction of the prediction model, laboratory-confirmed cases were grouped as "at-risk" (AR) infants and the discarded cases into "not at risk" (NAR) infants. Univariate analysis (p value cut-off < 0.05) followed by multivariate binary logistic regression model development was performed. RESULTS: The average (median) age of the suspected CRS infants was 3 (IQR 1-6) months, and the average (mean) age of their mothers was 25.8 ± 4.1 years. Out of the total infants, 81 (7.3%) died, 975 (88%) were alive, and 55 (5.0%) were lost to follow-up. The final model showed that the odds of cataract, retinopathy, glaucoma, microcornea, and age of the infant at presentation were 3.1 (2.2-4.3), 4.9(2.3-10.4), 2.7(1.1-5.9), 2.3(1.1-4.7), and 1.1 (1-1.1), respectively, for the AR infant as compared to NAR infant. AUC of final model was 0.68 (95% CI Delong, 0.64-0.72). Bootstrapping for calibration of the model showed satisfactory results. Nomogram, along with a web version, was developed. CONCLUSION: The developed nomogram would have a wide community-based utilization and will help in prioritizing attention to high-risk children, thereby avoiding loss to follow-up.

Pitfalls of rubella serology while on the brink of elimination: evaluation of national data, Belgium, 2017.

BackgroundIn Belgium, rubella serology is frequently requested in women of childbearing age, despite high vaccination coverage and a near-absence of congenital rubella cases. Different test kits are available and should be standardised by an international standard preparation.AimTo analyse and compare rubella serology practices in Belgian laboratories.MethodsAs part of the mandatory External Quality Assessment programme for rubella serology in Belgium, the national public health institute, Sciensano, sent a voluntary questionnaire concerning anti-rubella IgM/IgG analyses in women aged 15 to 45 years in 2017 to 130 laboratories.ResultsThe questionnaire response rate was 83.8% (109/130). The majority of 169,494 IgG analyses were performed on Roche (55%), Abbott (17%) and Diasorin (13%) analysers. Not all laboratories used the proposed international cut-off of 10 IU/mL. Assumed median seroprevalence ranged from 76.3% with Liaison (Diasorin) to 96.3% with Modular (Roche). Despite very low rubella incidence in Belgium, 93 laboratories performed 85,957 IgM analyses, with 748 positive and 394 grey zone results. The National Reference Centre for Measles, Mumps and Rubella virus and the National Reference Centre for Congenital infections did not confirm any positive rubella cases in 2017.ConclusionThis retrospective analysis shows that rubella serology results may differ considerably according to the assay used. It is therefore important to use the same test when comparing results or performing follow-up testing. The number of anti-rubella IgM analyses was very high. Incorrect use of IgM for screening women of childbearing age can lead to unwarranted anxiety and overuse of confirmation tests.

Standardization of an in-house multiplex real-time polymerase chain reaction for the simultaneous detection of Toxoplasma gondii, Rubella virus, cytomegalovirus, herpes simplex Virus 1 and 2, and Treponema pallidum infection among pregnant women.

BACKGROUND: An in-house multiplex real-time polymerase chain reaction (PCR) was developed in two cocktails for the identification of six Toxoplasma gondii, Rubella virus, cytomegalovirus, herpes simplex virus (1 and 2), and Treponema pallidum (syphilis) (TORCH-S) agents, which causes congenital infection among pregnant women. OBJECTIVE: Standardization and validation of an in-house multiplex real-time PCR assay for the detection of TORCH-S infection. METHODS: This study was conducted from February 2017 to February 2019. Primers specific for T. gondii, Rubella virus, cytomegalovirus, herpes simplex virus (1 and 2), and T. pallidum were designed using Primer3 software (https://bioinfo.ut.ee/primer3-0.4.0/). The primer sequences obtained were subjected to BLAST analysis using BLAST database. Synthetic DNA was obtained to use as positive control templates for all the six TORCH-S agents. The lower limit of the detection was performed using plasmid construct for each virus serially diluted from 10-1 to 10-9. RESULTS: An in-house multiplex real-time PCR was standardized and validated in two cocktails for TORCH-S agents, cocktail-1 (HSV1, rubella, and T. gondii), and cocktail-2 (HSV2, CMV, and T. pallidum). The lower limit of the detection for HSV1, rubella, and Toxoplasma were 60.7 copies/10 µl input, 76.4 copies/10 µl input, and 34.4 copies/10 µl input and for HSV2, CMV, and T. pallidum were 80.8 copies/10 µl input, 166 copies/10 µl input, and 43.7 copies/10 µl input, respectively. CONCLUSION: TORCH-S infection is one of the significant reasons for irregular pregnant outcomes. It is absolutely important to screen TORCH-S infection for women who had the histories of abnormal pregnancies to prevent birth defects and perinatal complications. This multiplex real-time PCR assay provides a rapid, sensitive, and specific technique to detect these six TORCH-S agents.

Performance Characteristics of a Multiplex Flow Immunoassay for Detection of IgG-Class Antibodies to Measles, Mumps, Rubella, and Varicella-Zoster Viruses in Presumptively Immune Health Care Workers.

Immunity to measles, mumps, rubella, and varicella-zoster viruses (VZV; MMRV) is a common condition of employment for health care workers (HCWs) to ensure compliance with national standards and state laws. When documentation of complete vaccination or laboratory-confirmed infection is not available, Advisory Committee on Immunization Practices (ACIP) criteria are used to guide vaccination or anti-MMRV IgG testing. We assessed the performance of the BioPlex 2200 MMRV IgG multiplex flow immunoassay (MFI; Bio-Rad Laboratories, Hercules, CA) and matched immunofluorescence assays (IFAs; MBL Bion, Des Plaines, IL) in 220 HCWs categorized by ACIP criteria for presumptive immunity to MMRV. Among HCWs presumptively immune to measles, mumps, rubella, and VZV, the Bio-Rad MFI was positive in 77.3, 85.4, 84.3, and 91.1% of HCWs, respectively. Comparatively, the Bion IFA was positive in 92.9, 91.1, and 93.5% of HCWs presumptively immune to measles, mumps, and VZV (a rubella IFA was unavailable). Among HCWs fully vaccinated against measles, mumps, and VZV, Bio-Rad MFI/Bion IFA positivity rates were 77.4%/93%, 84.8%/90.7%, and 54.5%/90.9%, respectively. The Bio-Rad MFI was positive in 83.7% of HCWs fully vaccinated against rubella. For HCWs whose last vaccination event occurred within 15 years of enrollment, 83.3, 93.3, and 74.2% were positive by the Bio-Rad measles, mumps, and rubella IgG MFIs, respectively. We show significantly decreased Bio-Rad MFI sensitivity for detection of anti-measles and anti-mumps IgG-class antibodies in presumptively immune or fully vaccinated HCWs. Although negative results typically prompt revaccination, failure to recognize presumptive immunity in individuals unable to receive live, attenuated vaccines may have employment implications.

Validation of monoplex assays detecting antibodies against Corynebacterium diphtheriae and Clostridium tetani toxins, rubella virus and parvovirus B19 for incorporation into Multiplex Serology.

Serological assays detecting antibodies in serum or plasma samples are useful and versatile instruments to investigate an individual's infection and vaccination history, e.g. for clinical diagnosis, personal risk evaluation, and seroepidemiological studies. Multiplex Serology is a suspension bead array-based high-throughput methodology for simultaneous measurement of antibodies against multiple pathogens in a single reaction vessel, thus economizing sample volume, measurement time, and costs. We developed and validated bead-based pathogen-specific Monoplex Serology assays, i.e. assays including only antigens for the respective pathogen, to detect antibodies against Corynebacterium diphtheriae and Clostridium tetani toxins, rubella virus and parvovirus B19. The developed assays expand the portfolio of existing pathogen-specific bead-based serology assays and can be efficiently incorporated into larger Multiplex Serology panels. The newly developed Monoplex Serology assays consist of only one antigen per infectious agent, expressed as Glutathione S-transferase-fusion proteins in E. coli. Specificity, sensitivity and Cohen's kappa statistics in comparison with routine clinical diagnostic assays were calculated for serum dilutions 1:100 and 1:1000. All pathogen-specific assays were successfully validated at both serum dilutions with the exception of rubella Monoplex Serology which showed impaired sensitivity (57.6%) at dilution 1:1000. Specificities of successfully validated Monoplex Serology assays ranged from 85.6% to 100.0% (median: 91.7%), and sensitivities from 81.3% to 95.8% (median: 90.9%); agreement with the reference assays ranged from substantial to almost perfect (kappa: 0.66-0.86, median: 0.78). Statistical performance and slim assay design enable efficient incorporation of the developed assays into Multiplex Serology.