Since the last case of indigenous rubella virus (RuV) was detected in 2009 in the Region of the Americas, sporadic rubella and congenital rubella cases have been confirmed, and subsequently, a low number of associated sequences have been reported. Fifty-one sequences of wild-type RuV, representing four genotypes (1E, 1G, 1J, and 2B), were reported from five countries, with confirmed sources of exposure for 46 cases. Phylogenetic analysis revealed the diversity of these viruses, showing no associations with sustained endemic transmission from previously endemic strains. Notably, 13 sequences were associated with travel from countries where no genetic information of wild-type viruses was available. In addition to sequences from postnatal and congenital infections, 23 sequences were collected from patients with diseases associated with RuV persistent infection. These findings highlight the Region's success in maintaining rubella elimination, emphasize its valuable contribution to global RuV molecular epidemiology, and address potential challenges in progressing toward the goal of rubella eradication.

More than 100 laboratories in the World Health Organization Global Measles and Rubella Laboratory Network (GMRLN) perform nucleic acid-based methods for case confirmation of measles or rubella infections and/or strain surveillance (genotyping). The quality of laboratory data is critical to ensure that diagnostic results and country reports to regional verification committees are based on accurate data. A molecular External Quality Assurance (mEQA) program was initiated by the US-CDC in 2014 to evaluate the performance of laboratories in the network. The inclusion of testing for measles and rubella viruses, with a focus on detection and genotyping, plus the diversity of assays and platforms employed required a flexible and comprehensive proficiency testing program. A stepwise introduction of new evaluation criteria gradually increased the stringency of the proficiency testing program, while giving laboratories time to implement the required changes. The mEQA program plays an important role in many processes in the GMRLN, including informing plans for the training of laboratory staff, access to reagents, and the submission of sequence data to global databases. The EQA program for Local Public Health Institutes in Japan is described as an example for national mEQA programs. As more laboratories initiate molecular testing, the mEQA will need to continue to expand and to adapt to the changing landscape for molecular testing.

The association between granulomas and vaccine-derived rubella virus (VDRV) in people with primary immune deficiencies (PID) has raised concerns about the ability of immunoglobulin (IG) preparations to neutralize VDRVs. We investigated the capacity of IG to neutralize rubella vaccine virus and four VDRV strains. As expected, the rubella vaccine virus itself was potently neutralized by IG preparations; however, the VDRV isolates from patients after intra-host evolution, 2-6 times less so. Diagnosis of immune deficiencies before possible live-virus vaccination is thus of critical importance, while IG replacement therapy can be expected to provide protection from rubella virus infection. | The occurrence of granulomas associated with vaccine derived rubella viruses (VDRV) in people with primary immune deficiencies (PID) challenges immunoglobulin (IG) preparations regarding their rubella neutralizing ability. This study confirmed potent rubella virus neutralization capacity of IG preparations and thus suggests protection of IG-treated PID patients against rubella. The study also highlights the importance of early diagnosis and timely given IG to prevent possible systemic spread of VDRV persisting locally in granulomas. | eng

BACKGROUND: A third dose of measles-mumps-rubella vaccine (MMR) may be administered for various reasons, but data on long-term immunity are limited. We assessed neutralizing antibody levels against measles and rubella among adults up to 11 years after receipt of a third MMR dose. METHODS: In this longitudinal study, healthy adults who received a third MMR dose as young adults (ages 18-28 years) were recalled around 5 years and 9-11 years after the third dose. Measles and rubella antibody levels were assessed by plaque-reduction and immunocolorimetric neutralization assays, respectively. Antibody concentrations <120 mIU/mL and <10 U/mL were considered potentially susceptible to measles and rubella, respectively. Geometric mean concentrations (GMCs) and 95% confidence intervals (CIs) over time were estimated from generalized estimating equation models. RESULTS: Approximately 5 and 9-11 years after receipt of the third dose, 405 and 304 adults were assessed, respectively. Measles GMC was 428 mIU/mL (95% CI, 392-468 mIU/mL) 5 years postvaccination, declining to 381 mIU/mL (95% CI, 339-428 mIU/mL) 11 years postvaccination. At the last follow-up visit (9-11 years postvaccination), 10% of participants were potentially susceptible to measles infection. Rubella GMCs were stable throughout the follow-up period (63 U/mL to 65 U/mL); none of the participants was susceptible to rubella at the last follow-up visit. CONCLUSIONS: Eleven years after receiving a third MMR dose, measles and rubella neutralizing antibody levels remained high in adults. However, on the basis of waning antibody levels, some adults may become susceptible to measles infection over time despite receipt of 3 vaccine doses.

Patients with inborn errors of immunity (IEI) may develop granulomas in multiple organ systems including the skin. Vaccine strain rubella virus (RuV), part of the live attenuated measles, mumps, and rubella (MMR) vaccine, has been identified within these granulomas. RuV is typically found in macrophages; however, recently neutrophils have been identified as a novel cell type infected. Here, we present a case of RuV-associated cutaneous granuloma with RuV localized to neutrophils. A 46-year-old female with common variable immunodeficiency presented with verrucous papules and crusted plaques from the right knee to the distal shin of 20 years duration, associated with prior physical trauma. Biopsy specimen showed palisaded granulomas surrounding central necrosis with scattered aggregates of neutrophils. Vaccine-derived RuV was detected by molecular sequencing in lesional skin. Fluorescent immunohistochemistry with CD206, myeloperoxidase (MPO), and RV capsid (RVC) antibodies demonstrated that RuV localized to neutrophils but not macrophages. The clinical presentation, cutaneous findings, and likely presence of RVC-positive granulocytes in bone marrow provide potential support to the evolving hypothesis of persistent RuV within neutrophils contributing to chronic granulomatous inflammation in a milieu of immune dysregulation.

The family Matonaviridae comprises enveloped viruses with positive-sense RNA genomes of 9.6-10 kb. The genus Rubivirus includes rubella virus (species Rubivirus rubellae) infecting humans, ruhugu virus (species Rubivirus ruteetense) infecting bats and rustrela virus (species Rubivirus strelense) infecting rodents and zoo animals. Rubella virus is spread via droplets. Postnatal infection leads to benign disease with rash and fever. Infection of seronegative women with rubella virus during the first trimester of pregnancy will often result in severe foetal malformations, known as congenital rubella syndrome. Vaccines are globally available. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Matonaviridae, which is available at ictv.global/report/matonaviridae.

A young man with X-linked severe combined immunodeficiency developed a persistent vaccine-derived rubella virus (VDRV) infection, with the emergence of cutaneous granulomas more than fifteen years after receipt of two doses of measles-mumps-rubella (MMR) vaccine. Following nasopharyngeal swab (NP) collection, VDRV was detected by real-time polymerase chain reaction (RT-qPCR) and sequencing, and live, replication-competent VDRV was isolated in cell culture. To assess duration and intensity of viral shedding, sequential respiratory samples, one cerebrospinal fluid sample, and two urine samples were collected over 15 months, and VDRV RNA was detected in all samples by RT-qPCR. Live VDRV was cultured from nine of the eleven respiratory specimens and from one urine specimen. To our knowledge, this was the first reported instance of VDRV cultured from respiratory specimens or from urine. To assess potential transmission to close contacts, NP specimens and sera were collected from all household contacts, all of whom were immunocompetent and previously vaccinated with MMR. VDRV RNA was not detected in any NP swabs from the contacts, nor did serologic investigations suggest VDRV transmission to any contacts. This report highlights the need to understand the prevalence and duration of VDRV shedding in granuloma patients and to estimate the risk of VDRV transmission to immune and non-immune contacts.

The preclinical time course of SARS-CoV-2 shedding is not well-described. Understanding this time course will help to inform risk of SARS-CoV-2 transmission. During an outbreak in a congregate setting, we collected paired mid-turbinate nasal swabs for antigen testing and reverse-transcription polymerase chain reaction (RT-PCR) every other day from all consenting infected and exposed persons. Among 12 persons tested prospectively before and during SARS-CoV-2 infection, ten of 12 participants (83%) had completed a primary COVID-19 vaccination series prior to the outbreak. We recovered SARS-CoV-2 in viral culture from 9/12 (75%) of participants. All three persons from whom we did not recover SARS-CoV-2 in viral culture had completed their primary vaccination series. We recovered SARS-CoV-2 from viral culture in 6/9 vaccinated persons and before symptom onset in 3/6 symptomatic persons. These findings underscore the need for both non-pharmaceutical interventions and vaccination to mitigate transmission.

The clinical presentation of varicella in unvaccinated persons, with skin vesicles and scabs, has facilitated the use of rapid diagnostic methods for confirming disease. Polymerase chain reaction (PCR) assays are the diagnostic method of choice. The sharp decline in unmodified cases of varicella due to the US varicella vaccination program has led to fewer healthcare providers being familiar with varicella presentation and an increased reliance on laboratory diagnosis to confirm suspected cases. The mild, atypical presentation of the disease in vaccinated persons (fewer skin lesions, mostly maculopapular) has made it more challenging for providers to recognize and also to collect samples to detect the virus. Nonetheless, PCR is highly sensitive and specific in confirming modified disease if adequate samples are provided. While a positive PCR result is confirmatory, interpreting a negative result can prove to be more challenging in determining whether suspected varicella is falsely negative or attributable to other causes. Enhanced education of healthcare providers is critical for adequate specimen collection from modified varicella cases. In addition, more sensitive commercial serologic assays are needed in the United States for varicella immunity testing in the vaccine era.

Enhanced replication of rubella virus (RuV) and replicons by de novo synthesized viral structural proteins has been previously described. Such enhancement can occur by viral capsid proteins (CP) alone in trans. It is not clear whether the CP in the virus particles, i.e., the exogenous CP, modulate viral genome replication. In this study, we found that exogenous RuV CP also enhanced viral genome replication, either when used to package replicons or when mixed with RNA during transfection. We demonstrated that CP does not affect the translation efficiency from genomic (gRNA) or subgenomic RNA (sgRNA), the intracellular distribution of the non-structural proteins (NSP), or sgRNA synthesis. Significantly active RNA replication was observed in transfections supplemented with recombinant CP (rCP), which was supported by accumulated genomic negative-strand RNA. rCP was found to restore replication of a few mutants in NSP but failed to fully restore replicons known to have defects in the positive-strand RNA synthesis. By monitoring the amount of RuV RNA following transfection, we found that all RuV replicon RNAs were well-retained in the presence of rCP within 24 h of post-transfection, compared to non-RuV RNA. These results suggest that the exogenous RuV CP increases efficiency of early viral genome replication by modulating the stage(s) prior to and/or at the initiation of negative-strand RNA synthesis, possibly through a general mechanism such as protecting viral RNA.

An examination of the nucleic acid sequence alignment of 48 full-length rubella virus genomes revealed that the 5' terminus of the genome is more conserved than the commonly used detection windows for rubella virus RNA located in the E1 protein coding region, suggesting that the 5' terminus could be a target for improving detection of all rubella virus genotypes. Two candidate primer sets were tested and the window between nucleotides (nts) 98 and 251 was found to have the greatest analytical sensitivity for detection of different genotypes. The new method had a limit of detection of four copies of rubella RNA per reaction with high specificity. The average coefficient variation of Ct was 2.2%. Concordance between the new method and currently used method, based on testing 251 clinical specimens collected from a rubella outbreak, was 99.4%. The assay was further improved upon by the incorporation of detection of both rubella virus RNA and mRNA from a cellular reference gene in a multiplex format. The multiplex format did not reduce the sensitivity or the reproducibility of rubella RNA detection and, of 60 specimens tested, the concordance between the single target and multiplex assays was 85.0%. To assess the utility of the multiplex assay for molecular surveillance, 62 rubella IgM positive serum samples from a rubella outbreak were tested, and eleven tested positive using the multiplex method while none were positive using the method targeting E1. These results show that the assay based on the new detection window near the 5' terminus of the genome can improve the detection of rubella virus for the purpose of molecular surveillance and case confirmation, with the added benefit of improved efficiency due to multiplexing.

IMPORTANCE: Vaccine-derived and wild-type rubella virus (RuV) has been identified within granulomas in patients with inborn errors of immunity, but has not been described in granulomas of healthy adults. OBJECTIVE: To determine the association between RuV and atypical granulomatous inflammation in immune-competent adults. DESIGN, SETTING, AND PARTICIPANTS: This case series, conducted in US academic dermatology clinics from January 2019 to January 2021, investigated the presence of RuV in skin specimens using RuV immunofluorescent staining of paraffin-embedded tissue sections, real-time reverse-transcription polymerase chain reaction, whole-genome sequencing with phylogenetic analyses, and cell culture by the US Centers for Disease Control and Prevention. Rubella immunoglobulin G, immunoglobulin M enzyme-linked immunoassay, and viral neutralization assays were performed for the sera of immunocompetent individuals with treatment refractory cutaneous granulomas and histopathology demonstrating atypical palisaded and necrotizing granulomas. Clinical immune evaluation was performed. MAIN OUTCOMES AND MEASURES: Identification, genotyping, and culture of vaccine-derived and wild-type RuV within granulomatous dermatitis of otherwise clinically immune competent adults. RESULTS: Of the 4 total immunocompetent participants, 3 (75%) were women, and the mean (range) age was 61.5 (49.0-73.0) years. The RuV capsid protein was detected by immunohistochemistry in cutaneous granulomas. The presence of RuV RNA was confirmed by real-time reverse-transcription polymerase chain reaction in fresh-frozen skin biopsies and whole-genome sequencing. Phylogenetic analysis of the RuV sequences showed vaccine-derived RuV in 3 cases and wild-type RuV in 1. Live RuV was recovered from the affected skin in 2 participants. Immunology workup results demonstrated no primary immune deficiencies. CONCLUSIONS AND RELEVANCE: The case series study results suggest that RuV (vaccine derived and wild type) can persist for years in cutaneous granulomas in clinically immunocompetent adults and is associated with atypical (palisaded and necrotizing type) chronic cutaneous granulomas. These findings represent a potential paradigm shift in the evaluation, workup, and management of atypical granulomatous dermatitis and raises questions regarding the potential transmissibility of persistent live RuV.

Rubella virus (RuV) has recently been found in association with granulomatous inflammation of the skin and several internal organs in patients with inborn errors of immunity (IEI). The cellular tropism and molecular mechanisms of RuV persistence and pathogenesis in select immunocompromised hosts are not clear. We provide clinical, immunological, virological, and histological data on a cohort of 28 patients with a broad spectrum of IEI and RuV-associated granulomas in skin and nine extracutaneous tissues to further delineate this relationship. Combined immunodeficiency was the most frequent diagnosis (67.8%) among patients. Patients with previously undocumented conditions, i.e., humoral immunodeficiencies, a secondary immunodeficiency, and a defect of innate immunity were identified as being susceptible to RuV-associated granulomas. Hematopoietic cell transplantation was the most successful treatment in this case series resulting in granuloma resolution; steroids, and TNF-α and IL-1R inhibitors were moderately effective. In addition to M2 macrophages, neutrophils were identified by immunohistochemical analysis as a novel cell type infected with RuV. Four patterns of RuV-associated granulomatous inflammation were classified based on the structural organization of granulomas and identity and location of cell types harboring RuV antigen. Identification of conditions that increase susceptibility to RuV-associated granulomas combined with structural characterization of the granulomas may lead to a better understanding of the pathogenesis of RuV-associated granulomas and discover new targets for therapeutic interventions.

IMPORTANCE: Immunodeficiency-related, vaccine-derived rubella virus (RuV) as an antigenic trigger of cutaneous and visceral granulomas is a rare, recently described phenomenon in children and young adults treated with immunosuppressant agents. OBJECTIVE: To perform a comprehensive clinical, histologic, immunologic, molecular, and genomic evaluation to elucidate the potential cause of an adult patient's atypical cutaneous granulomas. DESIGN, SETTING, AND PARTICIPANTS: A prospective evaluation of skin biopsies, nasopharyngeal swabs, and serum samples submitted to the Centers for Disease Control and Prevention was conducted to assess for RuV using real-time reverse-transcriptase polymerase chain reaction (RT-PCR) and viral genomic sequencing. The samples were obtained from a man in his 70s with extensive cutaneous granulomas mimicking both cutaneous sarcoidosis (clinically) and CD8+ granulomatous cutaneous T-cell lymphoma (histopathologically). The study was conducted from September 2019 to February 2021. MAIN OUTCOMES AND MEASURES: Identification and genotyping of a novel immunodeficiency-related RuV-associated granulomatous dermatitis. RESULTS: Immunohistochemistry for RuV capsid protein and RT-PCR testing for RuV RNA revealed RuV in 4 discrete skin biopsies from different body sites. In addition, RuV RNA was detected in the patient's nasopharyngeal swabs by RT-PCR. The full viral genome was sequenced from the patient's skin biopsy (RVs/Philadelphia.PA.USA/46.19/GR, GenBank Accession #MT249313). The patient was ultimately diagnosed with a novel RuV-associated granulomatous dermatitis. CONCLUSIONS AND RELEVANCE: The findings of this study suggest that clinicians and pathologists may consider RuV-associated granulomatous dermatitis during evaluation of a patient because it might have implications for the diagnosis of cutaneous sarcoidosis, with RuV serving as a potential antigenic trigger, and for the diagnosis of granulomatous cutaneous T-cell lymphoma, with histopathologic features that may prompt an evaluation for immunodeficiency and/or RuV.

BACKGROUND: While administration of the measles-mumps-rubella (MMR-II®) vaccine has been effective at preventing rubella infection in the United States, the durability of humoral immunity to the rubella component of MMR vaccine has not been widely studied among older adolescents and adults. METHODS: In this longitudinal study, we sought to assess the durability of rubella virus (RV)-specific humoral immunity in a healthy population (n = 98) of adolescents and young adults at two timepoints: ~7 and ~17 years after two doses of MMR-II® vaccination. Levels of circulating antibodies specific to RV were measured by ELISA and an immune-colorimetric neutralization assay. RV-specific memory B cell responses were also measured by ELISpot. RESULTS: Rubella-specific IgG antibody titers, neutralizing antibody titers, and memory B cell responses declined with increasing time since vaccination; however, these decreases were relatively moderate. Memory B cell responses exhibited a greater decline in men compared to women. CONCLUSIONS: Collectively, rubella-specific humoral immunity declines following vaccination, although subjects' antibody titers remain well above the currently recognized threshold for protective immunity. Clinical correlates of protection based on neutralizing antibody titer and memory B cell ELISpot response should be defined.

In the U.S., measles, mumps, and rubella vaccination is recommended as two vaccine doses. A third dose of measles-mumps-rubella (MMR) vaccine is being administered in certain situations (e.g., identified seronegativity and during outbreaks). We studied rubella-specific humoral immunity (neutralizing antibody, enzyme-linked immunosorbent assay/ELISA IgG titer and antibody avidity) and the frequencies of antigen-specific memory B cells before and after a third dose of MMR-II in 109 female participants of childbearing age (median age, 34.5years old) from Olmsted County, MN, with two documented prior MMR vaccine doses. The participants were selected from a cohort of 1117 individuals if they represented the high and the low ends of the rubella-specific antibody response spectrum. Of the 109 participants, we identified four individuals (3.67% of all study participants; 7.14% of the low-responder group) that were seronegative at Baseline (rubella-specific ELISA IgG titers <10IU/mL), suggesting a lack of protection against rubella before receipt of a third MMR vaccine dose. The peak geometric mean neutralizing antibody titer one month following the third dose of MMR vaccine for the cohort was 243 NT50 (CI; 241, 245), which is expected for a cohort with two doses of MMR, and the peak geometric mean IgG titer was 150IU/mL (CI; 148, 152) with no seronegative individuals at Day 28. One-third of all subjects (31.8% for the neutralizing antibody; 30.8% for the IgG titer) experienced a significant boost (>/=4-fold) of antibody titers one month following vaccination. Antibody titers and other tested immune-response variables were significantly higher in the high-responder group compared to the low-responder group. The frequencies of rubella-specific memory B cells were modestly associated with the antibody titers. Our study suggests the importance of yet unknown inherent biologic and immune factors for the generation and maintenance of rubella-vaccine-induced humoral immune responses.

Rubella viruses (RV) have been found in an association with granulomas in children with primary immune deficiencies (PID). Here, we report the recovery and characterization of infectious immunodeficiency-related vaccine-derived rubella viruses (iVDRV) from diagnostic skin biopsies of four patients. Sequence evolution within PID hosts was studied by comparison of the complete genomic sequences of the iVDRVs with the genome of the vaccine virus RA27/3. The degree of divergence of each iVDRV correlated with the duration of persistence indicating continuous intrahost evolution. The evolution rates for synonymous and nonsynonymous substitutions were estimated to be 5.7 x 10-3 subs/site/year and 8.9 x 10-4 subs/site/year, respectively. Mutational spectra and signatures indicated a major role for APOBEC cytidine deaminases and a secondary role for ADAR adenosine deaminases in generating diversity of iVDRVs. The distributions of mutations across the genes and 3D hotspots for amino acid substitutions in the E1 glycoprotein identified regions that may be under positive selective pressure. Quasispecies diversity was higher in granulomas than in recovered infectious iVDRVs. Growth properties of iVDRVs were assessed in WI-38 fibroblast cultures. None of the iVDRV isolates showed complete reversion to wild type phenotype but the replicative and persistence characteristics of iVDRVs were different from those of the RA27/3 vaccine strain, making predictions of iVDRV transmissibility and teratogenicity difficult. However, detection of iVDRV RNA in nasopharyngeal specimen and poor neutralization of some iVDRV strains by sera from vaccinated persons suggests possible public health risks associated with iVDRV carriers. Detection of IgM antibody to RV in sera of two out of three patients may be a marker of virus persistence, potentially useful for identifying patients with iVDRV before development of lesions. Studies of the evolutionary dynamics of iVDRV during persistence will contribute to development of infection control strategies and antiviral therapies.

The genetic characterization of measles viruses is an important tool for measles surveillance. Reverse cold chain requirements for the transportation of samples to reference laboratories are challenging in resource-limited settings. FTA(R) cards facilitate transport of virologic samples at ambient temperature as non-infectious material; however, the utility of FTA(R) cards for detection and genotyping of measles virus from clinical samples had not been evaluated. Throat swabs (TS) and oral fluid (OF) samples were collected from suspected measles cases in the Democratic Republic of the Congo. Virus detection (RT-qPCR) and genotyping (end-point RT-PCR) were compared for samples from 238 suspected cases; these samples were either transported using the reverse cold chain or at ambient temperature on FTA(R) cards. Virus detection showed excellent positive agreement for OF compared to TS (95.3%, CI [91.6, 97.4]), in contrast to 79.4% (CI 73.5, 84.3) for TS on FTA, and 85.5% (CI 80.2, 89.6) for OF on FTA compared to OF. Genotyping results obtained for a subset of samples indicated that 77.3% of all TS and 71.0% of OF would produce genotype information compared to 41.6% of TS and 41.3% of OF on FTA(R) cards. Similar results were found for 16 measles-negative samples that were confirmed as rubella cases. Measles genotype B3 and rubella genotype 2B were detected. FTA(R) cards have limited utility for virologic surveillance of sporadic cases of measles; however, they can be a useful tool for the expansion of virologic surveillance in countries where the reverse cold chain is not available.

Background: New methods to increase measles and rubella (MR) vaccination coverage are needed to achieve global and regional MR elimination goals. Methods: Here, we developed microneedle (MN) patches designed to administer MR vaccine by minimally trained personnel, leave no biohazardous sharps waste, remove the need for vaccine reconstitution, and provide thermostability outside the cold chain. This study evaluated the immunogenicity of MN patches delivering MR vaccine to infant rhesus macaques. Results: Protective titers of measles neutralizing antibodies (>120 mIU/mL) were detected in 100% of macaques in the MN group and 75% of macaques in the subcutaneous (SC) injection group. Rubella neutralizing antibody titers were >10 IU/mL for all groups. All macaques in the MN group were protected from challenge with wild-type measles virus, whereas 75% were protected in the SC group. However, vaccination by the MN or SC route was unable to generate protective immune responses to measles in infant macaques pretreated with measles immunoglobulin to simulate maternal antibody. Conclusions: These results show, for the first time, that MR vaccine delivered by MN patch generated protective titers of neutralizing antibodies to both measles and rubella in infant rhesus macaques and afforded complete protection from measles virus challenge.

Rubella viruses of genotypes 1E and 2B are currently the most frequently detected wild-type viruses in the world. Genotype 1E viruses from China have been genetically distinct from genotype 1E viruses found elsewhere, while genotype 2B viruses found in China are not distinguishable from genotype 2B viruses from other areas. Genetic clusters of viruses of both genotypes were defined previously using sequences of the 739-nt genotyping window. Here we report phylogenic analysis using whole genomic sequences from seven genotype 1E and three genotype 2B viruses which were isolated in China between 2000 and 2013 and confirm the subgrouping of current circulating genotypes 1E and 2B viruses. In addition, the whole genomic characterization of Chinese rubella viruses was clarified. The results indicated that the Chinese rubella viruses were highly conserved at the genomic level, and no predicted amino acid variations were found at positions where functional domains of the proteins were identified. Therefore, it gives us the idea that the rubella control and elimination goal should be achieved if vaccine immunization coverage continues maintaining at the high level.

BACKGROUND: Many cases of Fuchs' uveitis have been associated with persistent rubella virus infection. A 73-year-old male patient with typical Fuchs' Uveitis Syndrome (FUS) first experienced heterochromia of the left eye at the age fourteen, when rubella was endemic in the US. OBJECTIVES: The purposes of this report are to describe the patient's FUS clinical presentations and to characterize the virus detected in the vitreous fluid. STUDY DESIGN: The patient underwent a therapeutic pars plana vitrectomy in May 2013. A real-time RT-PCR assay for rubella virus was performed on the vitreous fluid by Focus Diagnostics. Additional real-time RT-PCR assays for rubella virus detection and RT-PCR assays for generation of templates for sequencing were performed at the Centers for Disease Control and Prevention (CDC). RESULTS: The results from Focus Diagnostics were positive for rubella virus RNA. Real-time RT-PCR assays at CDC were also positive for rubella virus. A rubella virus sequence of 739 nucleotides was determined and phylogenetic analysis showed that the virus was the sole member of a new phylogenetic group when compared to reference virus sequences. CONCLUSIONS: While FUS remains a clinical diagnosis, findings in this case support the association between rubella virus and the disease. Phylogenetic analysis provided evidence that this rubella virus was likely a previously undetected genotype which is no longer circulating. Since the patient had rubella prior to 1955, this sequence is from the earliest rubella virus yet characterized.

Rubella remains a social and economic burden due to the high incidence of congenital rubella syndrome (CRS) in some countries. For this reason, an accurate and efficient high-throughput measure of antibody response to vaccination is an important tool. In order to measure rubella-specific neutralizing antibodies in a large cohort of vaccinated individuals, a high-throughput immunocolorimetric system was developed. Statistical interpolation models were applied to the resulting titers to refine quantitative estimates of neutralizing antibody titers relative to the assayed neutralizing antibody dilutions. This assay, including the statistical methods developed, can be used to assess the neutralizing humoral immune response to rubella virus and may be adaptable for assessing the response to other viral vaccines and infectious agents.

Rubella virus is the causative agent of rubella, a mild rash illness, and a potent teratogenic agent when contracted by a pregnant woman. Global rubella control programs target the reduction and elimination of congenital rubella syndrome. Phylogenetic analysis of partial sequences of rubella viruses has contributed to virus surveillance efforts and played an important role in demonstrating that indigenous rubella viruses have been eliminated in the United States. Sixteen wild-type rubella viruses were chosen for whole genome sequencing. All 16 viruses were collected in the United States from 1961 to 2009 and are from 8 of the 13 known rubella genotypes. Phylogenetic analysis of 30 whole genome sequences produced a maximum likelihood tree giving high bootstrap values for all genotypes except provisional genotype 1a. Comparison of the 16 new complete sequences and 14 previously sequenced wild-type viruses found regions with clusters of variable amino acids. The 5' 250 nucleotides of the genome are more conserved than any other part of the genome. Genotype specific deletions in the untranslated region between the non-structural and structural open reading frames were observed for genotypes 2B and genotype 1G. No evidence was seen for recombination events among the 30 viruses. The analysis presented here is consistent with previous reports on the genetic characterization of rubella virus genomes. Conserved and variable regions were identified and additional evidence for genotype specific nucleotide deletions in the intergenic region was found. Phylogenetic analysis confirmed genotype groupings originally based on structural protein coding region sequences, which provides support for the WHO nomenclature for genetic characterization of wild-type rubella viruses.

An important aspect of laboratory surveillance for measles and rubella is the genetic characterization of circulating wild-type viruses to support molecular epidemiologic studies and to track transmission pathways. Virologic surveillance that is sufficient to document the interruption of transmission of measles and rubella viruses will be an essential criterion for verification of elimination. Laboratories in the World Health Organization (WHO) Measles and Rubella Laboratory Network have worked to improve and expand virologic surveillance as many regions move toward elimination of measles and rubella/congenital rubella syndrome. As countries approach elimination, it will be necessary to obtain genetic information from as many chains of transmission as possible. In addition, baseline virologic surveillance, especially for rubella, needs to be improved in many countries. This report contains a summary of recent improvements to the methods used for virologic surveillance.