Comparison of the sensitivity of laboratory diagnostic methods from a well-characterized outbreak of mumps in New York city in 2009

Serologic Cross-Reactivity between the Mumps Virus Vaccine Genotype A Strain and the Circulating Genotype G Strain

Recent mumps outbreaks have been observed in vaccinated young adults due to the mumps virus (MuV) of genotype G, whereas the current vaccine is a mixture of two genotype A strains. These outbreaks could be attributed to waning vaccine immunity or the antigenic differences between the HN and F glycoproteins in the vaccine and circulating MuV. These glycoproteins are essential targets for the immune system, and antigenic variations may reduce the recognition of mumps antibodies, rendering the population susceptible to the MuV. We established stable cell lines expressing the MuV glycoproteins to study cross-reactivity between genotype A and genotype G. Cross-reactivity between the genotypes was evaluated via immunofluorescence using patient sera from vaccinated individuals, infected individuals, and vaccinated individuals infected with genotype G. Titer ratios showed that the vaccinated individuals exhibited a titer 3.68 times higher for the HN protein and 2.3 times higher for the F protein when comparing genotype A with genotype G. In contrast, the infected individuals showed a lower titer for genotype A compared with genotype G, at 0.43 and 0.33 for the HN and F proteins, respectively. No difference in titer ratio was observed for individuals vaccinated and subsequently infected with mumps. These findings suggest that antigenic variations between the two genotypes may potentially result in immune escape of the circulating strain, resulting in individuals susceptible to the MuV.

Identifying a Level of Neutralizing Antibody That Correlates With Protection From Clinical Mumps Disease During a 2017 Mumps Outbreak Among Military Service Members

Background

In 2017, a mumps outbreak occurred in a US military barracks. Serum collected at service entry was used to compare pre-exposure with presumptive vaccine-induced antibody levels from persons who developed mumps (cases) and potentially exposed persons who did not develop mumps (non-cases). Sufficient information to determine levels of exposure during the outbreak was not available.

Methods

Pre-outbreak serum samples from the Department of Defense Serum Repository were available from 254 potentially exposed service members. Twelve developed clinical symptoms and had post-outbreak serum collected. All sera were tested with a mumps-specific enzyme immunoassay for immunoglobulin M, immunoglobulin G (IgG), and IgG avidity. The neutralizing antibodies to vaccine strain (Jeryl Lynn [JL], genotype A) and wildtype virus (genotype G) was assessed by a plaque reduction neutralization test. A Fisher exact test and receiver operator characteristic curve were used to analyze the antibody response for non-cases and mumps cases.

Results

Eight mumps cases were laboratory confirmed. Pre-outbreak neutralizing antibody titers to JL and genotype G mumps virus and pre-outbreak IgG index values were proportionately lower for most cases as compared with exposed non-cases. When compared with potentially exposed non-cases, cases with clinical symptoms had greater odds of having a pre-outbreak JL titer <41 and a genotype G titer <16.

Conclusions

We identified potential correlates of protection for mumps neutralizing antibody titers against JL and genotype G mumps viruses.

What is the relevancy of a surveillance of mumps without a systematic laboratory confirmation in highly immunized populations? Epidemiology of suspected and biologically confirmed mumps cases seen in general practice in France between 2014 and 2020

BACKGROUND

In France, mumps surveillance is conducted in primary care by the Sentinelles network, the National Reference Centre for Measles, Mumps and Rubella and Santé publique France.

AIM

The objective of this study was to estimate the incidence of suspected mumps in general practice, the proportion of laboratory confirmed cases and the factors associated with a virological confirmation.

METHODS

General practitioners (GPs) participating in the Sentinelles network should report all patients with suspected mumps according to a clinical definition in case of parotitis and a serological definition in case of clinical expression without parotitis. All suspected mumps cases reported between January 2014 and December 2020 were included. A sample of these cases were tested by real time reverse transcriptase polymerase chain reaction (RT-PCR) for mumps biological confirmation.

RESULTS

A total of 252 individuals with suspected mumps were included in the study. The average annual incidence rate of suspected mumps in general practice in France between 2014 and 2020 was estimated at 11 cases per 100,000 population [CI95%: 6-17]. A mumps confirmation RT-PCR test was performed on 146 cases amongst which 17 (11.5 %) were positive. Age (between 20 and 29 years old), the presence of a clinical complication and an exposure to a suspected mumps case within the 21 days prior the current episode were associated with a mumps biological confirmation.

CONCLUSION

If these results confirm the circulation of mumps virus in France, they highlight the limits of a surveillance without a systematic laboratory confirmation in highly immunized populations.

An individual level infectious disease model in the presence of uncertainty from multiple, imperfect diagnostic tests

Bayesian compartmental infectious disease models yield important inference on disease transmission by appropriately accounting for the dynamics and uncertainty of infection processes. In addition to estimating transition probabilities and reproductive numbers, these statistical models allow researchers to assess the probability of disease risk and quantify the effectiveness of interventions. These infectious disease models rely on data collected from all individuals classified as positive based on various diagnostic tests. In infectious disease testing, however, such procedures produce both false-positives and false-negatives at varying rates depending on the sensitivity and specificity of the diagnostic tests being used. We propose a novel Bayesian spatio-temporal infectious disease modeling framework that accounts for the additional uncertainty in the diagnostic testing and classification process that provides estimates of the important transmission dynamics of interest to researchers. The method is applied to data on the 2006 mumps epidemic in Iowa, in which over 6,000 suspected mumps cases were tested using a buccal or oral swab specimen, a urine specimen, and/or a blood specimen. Although all procedures are believed to have high specificities, the sensitivities can be low and vary depending on the timing of the test as well as the vaccination status of the individual being tested.

Nationwide and long-term molecular epidemiologic studies of mumps viruses that circulated in Japan between 1986 and 2017

In Japan, major mumps outbreaks still occur every 4–5 years because of low mumps vaccine coverage (30–40%) owing to the voluntary immunization program. Herein, to prepare for a regular immunization program, we aimed to reveal the nationwide and long-term molecular epidemiological trends of the mumps virus (MuV) in Japan. Additionally, we performed whole-genome sequencing (WGS) using next-generation sequencing to assess results from conventional genotyping using MuV sequences of the small-hydrophobic (SH) gene. We analyzed 1,064 SH gene sequences from mumps clinical samples and MuV isolates collected from 25 prefectures from 1986 to 2017. The results showed that six genotypes, namely B (110), F (1), G (900), H (3), J (41), and L (9) were identified, and the dominant genotypes changed every decade in Japan since the 1980s. Genotype G has been exclusively circulating since the early 2000s. Seven clades were identified for genotype G using SH sequence-based classification. To verify the results, we performed WGS on 77 representative isolates of genotype G using NGS and phylogenetically analyzed them. Five clades were identified with high bootstrap values and designated as Japanese clade (JPC)-1, -2, -3, -4, -5. JPC-1 and -3 accounted for over 80% of the total genotype G isolates (68.3 and 13.8%, respectively). Of these, JPC-2 and -5, were newly identified clades in Japan through this study. This is the first report describing the nationwide and long-term molecular epidemiology of MuV in Japan. The results provide information about Japanese domestic genotypes, which is essential for evaluating the mumps elimination progress in Japan after the forthcoming introduction of the mumps vaccine into Japan’s regular immunization program. Furthermore, the study shows that WGS analysis using NGS is more accurate than results obtained from conventional SH sequence-based classification and is a powerful tool for accurate molecular epidemiology studies.

Immunization Information Systems

Immunization (IZ) information systems (IISs) are confidential, computerized, population-based systems that collect and consolidate IZ data from vaccination providers. The American Academy of Pediatrics continues to support the development and implementation of IISs as a beneficial tool to provide quality health care for children. Since the last revision of the American Academy of Pediatrics policy statement on IISs in 2006, numerous public health events and new data demonstrate the importance and value of these systems in society and expand the functionality and benefits of IISs beyond the basic IZ database intended to improve childhood IZ rates. This policy statement update will describe additional functions and benefits of IISs, as well as persistent and novel challenges and barriers that these systems face and pose to practicing pediatricians. Pediatricians and other pediatric health care practitioners should be aware of the value of IISs to society, the incentives and barriers involved in incorporating IIS access into a medical practice, and the opportunities to improve IISs and their functionality and usability in daily pediatric practice.

Mumps in Vaccinated Children and Adolescents: 2007-2019

BACKGROUND

Despite a >99% reduction in US mumps cases after the introduction of mumps vaccine in 1967, outbreaks have occurred in schools and other settings involving vaccinated children and adolescents since 2006.

METHODS

We analyzed mumps cases reported by US health departments to the National Notifiable Diseases Surveillance System. We present the incidence and vaccination status of pediatric cases (age <18 years) during 2007-2019 and describe demographic, clinical, and vaccination characteristics of pediatric cases reported during the most recent resurgence in 2015-2019.

RESULTS

During 2007-2019, 9172 pediatric cases were reported, accounting for a median of 32% of all cases reported each year (range: 13%-59%). A median of 87% (range: 81%-94%) of pediatric patients each year had previously received ≥1 measles, mumps, and rubella (MMR) vaccine dose. During 2015-2019, of 5461 pediatric cases reported, only 2% of those with known import status (74%) were associated with international travel. One percent of patients had complications and 2% were hospitalized. Among patients aged ≥1 year with known vaccination status (72%), 74% of 1- to 4-year-olds had received ≥1 MMR dose and 86% of 5- to 17-year-olds had received ≥2 MMR doses. Since 2016, pediatric mumps cases have been reported in most US states each year (range: 38-45 states).

CONCLUSIONS

Since 2007, one-third of US reported mumps cases occurred in children and adolescents, the majority of whom were vaccinated. Clinicians should suspect mumps in patients with parotitis or mumps complications, regardless of age, travel history, and vaccination status.

Pediatricians' Knowledge and Practices Related to Mumps Diagnosis and Prevention

OBJECTIVES

To assess pediatricians' mumps knowledge and testing practices, to identify physician and practice characteristics associated with mumps testing practices, and to assess reporting and outbreak response knowledge and practices.

STUDY DESIGN

Between January and April 2020, we surveyed a nationally representative network of pediatricians. Descriptive statistics were generated for all items. The χ2 test, t tests, and Poisson regression were used to compare physician and practice characteristics between respondents who would rarely or never versus sometimes or often/always test for mumps in a vaccinated 17-year-old with parotitis in a non-outbreak setting.

RESULTS

The response rate was 67% (297 of 444). For knowledge, more than one-half of the pediatricians responded incorrectly or "don't know" for 6 of the 9 true/false statements about mumps epidemiology, diagnosis, and prevention, and more than one-half reported needing additional guidance on mumps buccal swab testing. For testing practices, 59% of respondents reported they would sometimes (35%) or often/always (24%) test for mumps in a vaccinated 17-year-old with parotitis in a non-outbreak setting; older physicians, rural physicians, and physicians from the Northeast or Midwest were more likely to test for mumps. Thirty-six percent of the pediatricians reported they would often/always report a patient with suspected mumps to public health authorities.

CONCLUSIONS

Pediatricians report mumps knowledge gaps and practices that do not align with public health recommendations. These gaps may lead to underdiagnosis and underreporting of mumps cases, delaying public health response measures and contributing to ongoing disease transmission.

Streamlined Whole Genome Sequencing of Mumps for High Resolution Outbreak Analysis

Since 2015, the United States has experienced a resurgence in the number of mumps cases and outbreaks in fully vaccinated populations. These outbreaks have occurred predominantly in close quarter settings such as camps, colleges and detention centers. Phylogenetic analysis of 758 mumps positive samples from outbreaks across the United States, identified 743 (98%) as genotype G based on sequence analysis of the mumps small hydrophobic (SH) gene. Additionally, SH sequences in the genotype G samples showed almost no sequence diversity, with 675 (91%) of them having identical sequences or only one nucleotide difference. This uniformity of circulating genotype and strain created complications for epidemiologic investigations and necessitated the development of a system for rapidly generating mumps whole genome sequences for more detailed analysis. In this study, we report a novel and streamlined assay for whole genome sequencing (WGS) of mumps virus genotype G. The WGS procedure successfully generated 318 high-quality WGS sequences on nucleic acid from genotype G-positive respiratory samples collected during several mumps outbreaks in the United States between 2016-2019. Sequencing was performed by a rapid and highly sensitive custom Ion AmpliSeq mumps genotype G panel, with sample preparation performed on an Ion Chef and sequencing on an Ion S5. The WGS data generated by the AmpliSeq panel provided enhanced genomic resolution for epidemiological outbreak investigations. Translation and protein sequence analysis also identified several potentially important epitope changes in the circulating mumps genotype G strains compared to the Jeryl-Lynn strain (JL5) used in vaccines in the United States which could explain the current level of vaccine escapes.

Identification and description of mumps cases in a non-outbreak setting and evaluation of the effectiveness of mumps-containing vaccines over time

Mumps outbreaks among previously vaccinated young adults raise concerns regarding waning vaccine immunity. This study identified, described and assessed the changing incidence of mumps cases following mumps-containing vaccination (MMR/MMRV) in a non-mumps outbreak setting. Potential cases between 1996 and 2018 were identified by the international classification of disease codes or by mumps laboratory test orders among Kaiser Permanente Northern California members. Medical charts were reviewed to confirm diagnoses, timing relative to vaccination and clinical characteristics. Among 474 potential cases, 257 (54.2%) were confirmed after chart review. A third of the cases were <10 years old at diagnosis and 48% were over 25 years. Most cases (92.2%) had parotitis and 5% of males had orchitis. Mumps rates decreased from 8.5 to 1.8/1,000,000 person-years as time since the second MMR/MMRV dose increased from <2 years to ≥10 years. Similarly, rates decreased from 16.3 to 3/1,000,000 person-years after at least 1 dose of MMR/MMRV. Mumps rates were higher among children aged ≤10 years compared with older age groups. In conclusion, in the context of a non-outbreak setting, this study suggests that waning of vaccine immunity to mumps appeared to have minimal clinical impact.

Mumps Outbreaks in Vaccinated Populations-Is It Time to Re-assess the Clinical Efficacy of Vaccines?

History illustrates the remarkable public health impact of mass vaccination, by dramatically improving life expectancy and reducing the burden of infectious diseases and co-morbidities worldwide. It has been perceived that if an individual adhered to the MMR vaccine schedule that immunity to mumps virus (MuV) would be lifelong. Recent mumps outbreaks in individuals who had received two doses of the Measles Mumps Rubella (MMR) vaccine has challenged the efficacy of the MMR vaccine. However, clinical symptoms, complications, viral shedding and transmission associated with mumps infection has been shown to be reduced in vaccinated individuals, demonstrating a benefit of this vaccine. Therefore, the question of what constitutes a good mumps vaccine and how its impact is assessed in this modern era remains to be addressed. Epidemiology of the individuals most affected by the outbreaks (predominantly young adults) and variance in the circulating MuV genotype have been well-described alluding to a collection of influences such as vaccine hesitancy, heterogeneous vaccine uptake, primary, and/or secondary vaccine failures. This review aims to discuss in detail the interplay of factors thought to be contributing to the current mumps outbreaks seen in highly vaccinated populations. In addition, how mumps diagnoses has progressed and impacted the understanding of mumps infection since a mumps vaccine was first developed, the limitations of current laboratory tests in confirming protection in vaccinated individuals and how vaccine effectiveness is quantified are also considered. By highlighting knowledge gaps within this area, this state-of-the-art review proposes a change of perspective regarding the impact of a vaccine in a highly vaccinated population from a clinical, diagnostic and public perspective, highlighting a need for a paradigm shift on what is considered vaccine immunity.

Presence of low mumps-specific IgG in oral fluids is associated with high mumps viral loads

BACKGROUND

Mumps outbreaks continue to occur in highly vaccinated populations. Although the diagnosis of mumps is primarily based on clinical symptoms, other viral infections such as parainfluenza can manifest in a similar manner. Therefore, laboratory confirmation of mumps virus infection is important.

OBJECTIVES

The aims of this study were to examine mumps cases during the January 2018 to March 2019 period in Ireland as well as to evaluate the association between mumps RNA viral loads, mumps IgG levels, age and gender among patients with laboratory-confirmed mumps virus infection.

STUDY DESIGN

Oral fluid samples requested for mumps RNA testing (n = 1296) were included in the study. The mumps N gene was detected by real time PCR and reported as Ct values.

RESULTS

The proportion of samples received monthly with detectable mumps RNA increased from 10.26%-70.3% during the recent outbreak. Acute mumps cases occurred predominantly in the 16-25 years old age cohort (67.5 %) and in males (55.9 %). Mumps RNA viral loads were significantly higher in females (p < 0.001). During the outbreak, a significantly higher proportion of samples had Ct <30 (p < 0.05). A significant correlation was observed between mumps IgG levels and Ct values in oral fluid samples (p < 0.0001).

CONCLUSIONS

The presence of low mumps virus-specific IgG in oral fluids is significantly associated with high mumps viral loads. Our findings show that mumps virus is maintained in circulation in the non-outbreak period and acute mumps cases occur predominantly in the MMR vaccinated young adult male population.

In vitro inhibition of mumps virus replication by favipiravir (T-705)

During the last decade multiple mumps outbreaks have occurred in the U.S. despite high two dose MMR coverage with most cases detected among two dose MMR vaccine recipients. Waning immunity, the evolution of wild-type virus strains, and settings with intense exposure have contributed to the resurgence of mumps. Typically, mumps virus infections resolve without serious clinical sequelae; however, serious complications may occur among unvaccinated or severely immunocompromised individuals. Favipiravir (T-705) has been shown to have in vitro anti-viral activity against a broad range of positive and negative strand RNA viruses. Here, we demonstrate that T-705 inhibits the growth of wildtype and vaccine strains of mumps virus in vitro at low micro-molar concentrations (EC₅₀ 8-10μM). We did not observe the development of resistance after five subsequent passages at low concentrations of drug. Both viral RNA and protein synthesis were selectively reduced compared to host mRNA and protein synthesis. Antiviral treatment options for mumps virus infection may be valuable, especially for areas with a high disease burden or for cases with severe complications. These results presented here suggest that further studies are warranted.

Genetic characterization of mumps viruses associated with the resurgence of mumps in the United States: 2015-2017

Despite high coverage with measles, mumps, and rubella vaccine in the United States, outbreaks of mumps occur in close contact settings such as schools, colleges, and camps. Starting in late 2015, outbreaks were reported from several universities, and by the end of 2017, greater than 13,800 cases had been reported nation-wide. In 2013, the CDC and the Association of Public Health Laboratories contracted four Vaccine Preventable Diseases Reference Centers (VPD-RCs) to perform real-time reverse transcription PCR (RT-qPCR) to detect mumps RNA in clinical samples and to determine the genotype. Twelve genotypes of mumps virus are currently recognized by the World Health Organization, and the standard protocol for genotyping requires sequencing the entire gene coding for the small hydrophobic (SH) protein. Phylogenetic analysis of the 1862 mumps samples genotyped from 2015 through 2017 showed that the overall diversity of genotypes detected was low. Only 0.8 % of the sequences were identified as genotypes C, H, J, or K, and 0.5 % were identified as vaccine strains in genotypes A or N, while most sequences (98.7 %) were genotype G. The majority of the genotype G sequences could be included into one of two large groups with identical SH sequences. Within genotype G, a small number of phylogenetically significant outlier sequences were associated with epidemiologically distinct chains of transmission. These results demonstrate that molecular and epidemiologic data can be used to track transmission pathways of mumps virus; however, the limited diversity of the SH sequences may be insufficient for resolving transmission in all outbreaks.

S1 guidelines "lumbar puncture and cerebrospinal fluid analysis" (abridged and translated version)

Introduction

Cerebrospinal fluid (CSF) analysis is important for detecting inflammation of the nervous system and the meninges, bleeding in the area of the subarachnoid space that may not be visualized by imaging, and the spread of malignant diseases to the CSF space. In the diagnosis and differential diagnosis of neurodegenerative diseases, the importance of CSF analysis is increasing. Measuring the opening pressure of CSF in idiopathic intracranial hypertension and at spinal tap in normal pressure hydrocephalus constitute diagnostic examination procedures with therapeutic benefits.Recommendations (most important 3-5 recommendations on a glimpse): The indications and contraindications must be checked before lumbar puncture (LP) is performed, and sampling CSF requires the consent of the patient.Puncture with an atraumatic needle is associated with a lower incidence of postpuncture discomfort. The frequency of postpuncture syndrome correlates inversely with age and body mass index, and it is more common in women and patients with a history of headache. The sharp needle is preferably used in older or obese patients, also in punctures expected to be difficult.In order to avoid repeating LP, a sufficient quantity of CSF (at least 10 ml) should be collected. The CSF sample and the serum sample taken at the same time should be sent to a specialized laboratory immediately so that the emergency and basic CSF analysis program can be carried out within 2 h.The indication for LP in anticoagulant therapy should always be decided on an individual basis. The risk of interrupting anticoagulant therapy must be weighed against the increased bleeding risk of LP with anticoagulant therapy.As a quality assurance measure in CSF analysis, it is recommended that all cytological, clinical-chemical, and microbiological findings are combined in an integrated summary report and evaluated by an expert in CSF analysis.

Conclusions

In view of the importance and developments in CSF analysis, the S1 guideline "Lumbar puncture and cerebrospinal fluid analysis" was recently prepared by the German Society for CSF analysis and clinical neurochemistry (DGLN) and published in German in accordance with the guidelines of the AWMF (https://www.awmf.org). /uploads/tx_szleitlinien/030-141l_S1_Lumbalpunktion_und_Liquordiagnostik_2019-08.pdf). The present article is an abridged translation of the above cited guideline. The guideline has been jointly edited by the DGLN and DGN.

Current Status of Mumps Virus Infection: Epidemiology, Pathogenesis, and Vaccine

Mumps is an important childhood infectious disease caused by mumps virus (MuV). We reviewed the epidemiology, pathogenesis, and vaccine development of mumps. Previous studies were identified using the key words “mumps” and “epidemiology”, “pathogenesis” or “vaccine” in MEDLINE, PubMed, Embase, Web of Science, and Google Scholar. We excluded the articles that were not published in the English language, manuscripts without abstracts, and opinion articles from the review. The number of cases caused by MuV decreased steeply after the introduction of the mumps vaccine worldwide. In recent years, a global resurgence of mumps cases in developed countries and cases of aseptic meningitis caused by some mumps vaccine strains have renewed the importance of MuV infection worldwide. The performance of mumps vaccination has become an important issue for controlling mumps infections. Vaccine development and routine vaccination are still effective measures to globally reduce the incidence of mumps infections. During outbreaks, a third of MMR vaccine is recommended for groups of persons determined by public authorities.

Mumps: an Update on Outbreaks, Vaccine Efficacy, and Genomic Diversity

Mumps is an acute viral infection characterized by inflammation of the parotid and other salivary glands. Persons with mumps are infectious from 2 days before through 5 days after parotitis onset, and transmission is through respiratory droplets. Despite the success of mumps vaccination programs in the United States and parts of Europe, a recent increase in outbreaks of mumps virus infections among fully vaccinated populations has been reported. Although the effectiveness of the mumps virus component of the measles-mumps-rubella (MMR) vaccine is suboptimal, a range of contributing factors has led to these outbreaks occurring in high-vaccination-coverage settings, including the intensity of exposure, the possibility of vaccine strain mismatch, delayed implementation of control measures due to the timeliness of reporting, a lack of use of appropriate laboratory tests (such as reverse transcription-PCR), and time since last vaccination. The resurgence of mumps virus infections among previously vaccinated individuals over the past decade has prompted discussions about new strategies to mitigate the risk of future outbreaks. The decision to implement a third dose of the MMR vaccine in response to an outbreak should be considered in discussions with local public health agencies. Traditional public health measures, including the isolation of infectious persons, timely contact tracing, and effective communication and awareness education for the public and medical community, should remain key interventions for outbreak control. Maintaining high mumps vaccination coverage remains key to U.S. and global efforts to reduce disease incidence and rates of complications.

Combining genomics and epidemiology to track mumps virus transmission in the United States

Unusually large outbreaks of mumps across the United States in 2016 and 2017 raised questions about the extent of mumps circulation and the relationship between these and prior outbreaks. We paired epidemiological data from public health investigations with analysis of mumps virus whole genome sequences from 201 infected individuals, focusing on Massachusetts university communities. Our analysis suggests continuous, undetected circulation of mumps locally and nationally, including multiple independent introductions into Massachusetts and into individual communities. Despite the presence of these multiple mumps virus lineages, the genomic data show that one lineage has dominated in the US since at least 2006. Widespread transmission was surprising given high vaccination rates, but we found no genetic evidence that variants arising during this outbreak contributed to vaccine escape. Viral genomic data allowed us to reconstruct mumps transmission links not evident from epidemiological data or standard single-gene surveillance efforts and also revealed connections between apparently unrelated mumps outbreaks.

Infectious vaccine-derived rubella viruses emerge, persist, and evolve in cutaneous granulomas of children with primary immunodeficiencies

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.

Mumps Outbreak in a Highly Vaccinated University-Affiliated Setting Before and After a Measles-Mumps-Rubella Vaccination Campaign-Iowa, July 2015-May 2016

Background

In response to a mumps outbreak at the University of Iowa and surrounding community, university, state, and local health officials implemented a vaccination campaign targeting students <25 years of age with an additional dose of measles-mumps-rubella (MMR) vaccine. More than 4700 vaccine campaign doses were administered; 97% were documented third doses. We describe the epidemiology of the outbreak before and after the campaign, focusing on cases in university students.

Methods

Mumps cases were identified from reportable disease databases and university health system records. Detailed information on student cases was obtained from interviews, medical chart abstractions, university and state vaccination records, and state public health laboratory results. Pre- and postcampaign incidence among students, university faculty/staff, and community members <25 vs ≥25 years old were compared using Fisher exact test. Multivariable regression modeling was performed to identify variables associated with a positive mumps polymerase chain reaction test.

Results

Of 453 cases in the county, 301 (66%) occurred in university students. Student cases were primarily undergraduates (90%) and highly vaccinated (86% had 2 MMR doses, and 12% had 3 MMR doses). Fewer cases occurred in students after the campaign (75 [25%]) than before (226 [75%]). Cases in the target group (students <25 years of age) declined 9% postcampaign (P=.01). A positive mumps polymerase chain reaction test was associated with the presence of parotitis and early sample collection, and inversely associated with recent receipt of MMR vaccine.

Conclusions

Following a large additional dose MMR vaccination campaign, fewer mumps cases occurred overall and in the target population.

Decreased humoral immunity to mumps in young adults immunized with MMR vaccine in childhood

In the past decade, multiple mumps outbreaks have occurred in the United States, primarily in close-contact, high-density settings such as colleges, with a high attack rate among young adults, many of whom had the recommended 2 doses of mumps-measles-rubella (MMR) vaccine. Waning humoral immunity and the circulation of divergent wild-type mumps strains have been proposed as contributing factors to mumps resurgence. Blood samples from 71 healthy 18- to 23-year-old college students living in a non-outbreak area were assayed for antibodies and memory B cells (MBCs) to mumps, measles, and rubella. Seroprevalence rates of mumps, measles, and rubella determined by IgG enzyme-linked immunosorbent assay (ELISA) were 93, 93, and 100%, respectively. The index standard ratio indicated that the concentration of IgG was significantly lower for mumps than rubella. High IgG avidity to mumps Enders strain was detected in sera of 59/71 participants who had sufficient IgG levels. The frequency of circulating mumps-specific MBCs was 5 to 10 times lower than measles and rubella, and 10% of the participants had no detectable MBCs to mumps. Geometric mean neutralizing antibody titers (GMTs) by plaque reduction neutralization to the predominant circulating wild-type mumps strain (genotype G) were 6-fold lower than the GMTs against the Jeryl Lynn vaccine strain (genotype A). The majority of the participants (80%) received their second MMR vaccine ≥10 years prior to study participation. Additional efforts are needed to fully characterize B and T cell immune responses to mumps vaccine and to develop strategies to improve the quality and durability of vaccine-induced immunity.

Unusual, stable replicating viruses generated from mumps virus cDNA clones

In reverse genetic experiments we have isolated recombinant mumps viruses (rMuV) that carry large numbers of mutations clustered in small parts of their genome, which are not caused by biased hyper-mutation. In two separate experiments we obtained such recombinant viruses: one virus had 11 mutations in the V/P region of the genome; the other, which also contained an extra transcription unit encoding green fluorescent protein (EGFP), had 32 mutations in the N gene. These specific sets of mutations have not been observed in naturally occurring MuV isolates. Unusually, the vast majority of the mutations (48/51) were synonymous. On passage in Vero cells and human B-LCL cells, a B lymphocyte-like cell line, these mutations appear stable as no reversion occurred to the original consensus sequence, although mutations in other parts of the genome occurred and changed in frequency during passage. Defective interfering RNAs accumulate in passage in Vero cells but not in B-LCL cells. Interestingly, in all passaged samples the level of variation in the EGFP gene is the same as in the viral genes, though it is unlikely that this gene is under any functionality constraint. What mechanism gave rise to these viruses with clustered mutations and their stability remains an open question, which is likely of interest to a wider field than mumps reverse genetics.

Viral mumps: Increasing occurrences in the vaccinated population

Before the introduction of the vaccine, mumps was the most common salivary gland disease and was one of the most common infectious diseases in children globally. Following the introduction of the mumps vaccine in 1967, the disease was almost nonexistent in the United States and was only found to occur in nonvaccinated patients, and even then, it did not present in epidemic portions because of the extent of vaccination in the population at large. Beginning in the early 2000s, viral mumps began to present itself in vaccinated populations, and currently, outbreaks are continuing to increase in number. This article presents information on the various outbreaks, a review of the virus and the disease, including symptoms and comorbidities, and new recommendations for management. Dental practitioners should be aware of the increasing incidence and prevalence of this disease, be able to recognize it, and make appropriate referrals for management.

Genomic signature of early T-cell response is associated with lower antibody titer threshold for sterilizing immunity

Vaccination is an effective approach to reduce disease burden. High vaccination coverage blocks pathogen transmission to ensure herd immunity. However, the concept of herd immunity assumes that vaccinated individuals cannot be infected and mediate silent pathogen transmission. While the correlates of vaccine-mediated protection against disease have been examined, the correlates of sterilizing immunity that prevents infection have not been systematically defined. Here, we used full genome expression profiling to explore the molecular correlates of serological response and non-response to measles, mumps and rubella (MMR) vaccination as surrogates of infection and sterilizing immunity, respectively. We observed that the antibody titers needed to sterilize infection with the vaccine strains were higher than current WHO disease protection thresholds. In subjects with baseline antibodies below such sterilizing immunity thresholds, serological non-response to MMR vaccination was associated with gene expression profile indicative of early T-cell activation and signalling. Specifically, genes that regulate T-cell function and response were induced at day 1 post-vaccination in non-responders but not in responders. These findings suggest that rapid T-cell response prevented MMR vaccine infection to limit antigenic presentation and hence serological response. Collectively, our findings suggest an important role for T-cells in engendering sterilizing immunity.

Mumps epidemiology in Cuba between 2004 and 2015

Vaccination with the measles, mumps and rubella vaccine decreased the mumps incidence in Cuba, but in 2006 and 2007 an outbreak with more than 1000 laboratory confirmed cases occurred, mainly among high school and university students. The objective of the study was to investigate mumps epidemiology in Cuba between 2004 and 2015 and provide an in-depth laboratory characterization of selected samples from mumps patients. Samples from 116 cases (throat swabs, urines, paired acute and convalescent serum samples) were tested for mumps-specific IgM antibodies by ELISA, in a hemagglutination inhibition assay (HIA) or by RT-PCR. IgM antibodies were found in 80.2% of cases. 48.3% of first sera were positive, 30 of which were collected within two days after symptom onset. Testing of all 116 paired sera by HIA showed seroconversion in 55.2% individuals and an at least fourfold increase in antibodies in 44.8% of cases. In 18 out of the 111 vaccinated people (16.2%) no IgM antibodies were detected, neither in the acute nor the convalescent sera, but 14 of them showed seroconversion by HIA and 4 had an at least fourfold increase of hemagglutinin antibody titers. In the RT-PCR, 23 acute phase sera, 4 throat swabs and 5 urines were positive. Detection of mumps-specific IgM antibodies by ELISA and additional diagnostic methods may be required in settings with high vaccination coverage rates.

Non-mumps Viral Parotitis During the 2014-2015 Influenza Season in the United States

Background

During the 2014-2015 US influenza season, 320 cases of non-mumps parotitis (NMP) among residents of 21 states were reported to the Centers for Disease Control and Prevention (CDC). We conducted an epidemiologic and laboratory investigation to determine viral etiologies and clinical features of NMP during this unusually large occurrence.

Methods

NMP was defined as acute parotitis or other salivary gland swelling of >2 days duration in a person with a mumps- negative laboratory result. Using a standardized questionnaire, we collected demographic and clinical information. Buccal samples were tested at the CDC for selected viruses, including mumps, influenza, human parainfluenza viruses (HPIVs) 1-4, adenoviruses, cytomegalovirus, Epstein-Barr virus (EBV), herpes simplex viruses (HSVs) 1 and 2, and human herpes viruses (HHVs) 6A and 6B.

Results

Among the 320 patients, 65% were male, median age was 14.5 years (range, 0-90), and 67% reported unilateral parotitis. Commonly reported symptoms included sore throat (55%) and fever (48%). Viruses were detected in 210 (71%) of 294 NMP patients with adequate samples for testing, ≥2 viruses were detected in 37 samples, and 248 total virus detections were made among all samples. These included 156 influenza A(H3N2), 42 HHV6B, 32 EBV, 8 HPIV2, 2 HPIV3, 3 adenovirus, 4 HSV-1, and 1 HSV-2. Influenza A(H3N2), HHV6B, and EBV were the most frequently codetected viruses.

Conclusions

Our findings suggest that, in addition to mumps, clinicians should consider respiratory viral (influenza) and herpes viral etiologies for parotitis, particularly among patients without epidemiologic links to mumps cases or outbreaks.

Laboratory testing and phylogenetic analysis during a mumps outbreak in Ontario, Canada

BACKGROUND

In September 2009, a mumps outbreak originated in New York and spread to Northeastern USA and Canada. This study compares the performance of different diagnostic testing methods used in Ontario and describes molecular characteristics of the outbreak strain.

METHODS

Between September 2009 and February 2010, specimens from suspect cases were submitted to Public Health Ontario Laboratory for mumps serology, culture and/or real-time reverse-transcriptase PCR (rRT-PCR) testing. rRT-PCR-positive specimens underwent genotyping at Canada's National Microbiology Laboratory. Whole genome sequencing was performed on four outbreak and three sporadic viral culture isolates.

RESULTS

Six hundred ninety-eight patients had IgM serology testing, of which 255 (37%) had culture and rRT-PCR. Among those, 35/698 (5%) were IgM positive, 39/255 (15%) culture positive and 47/255 (18%) rRT-PCR-positive. Buccal swabs had the highest rRT-PCR positivity (21%). The outbreak isolates were identical to that in the New York outbreak occurring at the same time. Nucleotide and amino acid identity with the Jeryl Lynn vaccine strain ranged from 85.0-94.5% and 82.4-99.4%, depending on the gene and coding sequences. Homology of the HN protein, the main immunogenic mumps virus protein, was found to be 94.5 and 95.3%, when compared to Jeryl Lynn vaccine major and minor components, respectively.

CONCLUSIONS

Despite higher sensitivity than serology, rRT-PCR testing is underutilized. Further work is needed to better understand the suboptimal match of the HN gene between the outbreak strain and the Jeryl Lynn vaccine strain.

Diagnostic Yield of Laboratory Methods and Value of Viral Genotyping during an Outbreak of Mumps in a Partially Vaccinated Population in British Columbia, Canada

Mumps remains endemic in North America despite routine use of the measles, mumps, and rubella (MMR) vaccine. In 2016, an outbreak of mumps in British Columbia, Canada, provided an opportunity to determine the diagnostic utility of laboratory testing methods. Specimens from patients with clinical mumps were tested for infection using a commercial enzyme-linked immunosorbent assay (ELISA) for antibody detection and an in-house reverse transcriptase PCR (RT-PCR) targeting viral fusion and small hydrophobic (SH) genes. Viral genotyping was performed by SH gene sequencing. Laboratory data was linked with epidemiologic case data. Of the 139 confirmed cases, 94 (68%) had reported or documented history of MMR vaccination. Specimens were typically collected 1 day (for buccal and IgM tests) or 2 days (for urine tests) after symptom onset. Most confirmed cases (69%) were confirmed by buccal swab RT-PCR. Among cases tested by multiple methods, the percent positivity for buccal swab RT-PCR was 90% (96/107) compared to 43% (30/69) for both IgM ELISA and urine RT-PCR. Mumps IgM detection was higher in confirmed cases with no history of vaccination than in those with history (64% versus 34%, P = 0.02). The outbreak strain was identified as genotype G related to MuVi/Sheffield.GBR/1.05 but with conserved variations in five nucleotides within the SH gene that allowed linkage of geographically distinct cases. In conclusion, RT-PCR of buccal specimens had the highest diagnostic yield during a mumps outbreak in a partially vaccinated population. To optimize mumps diagnostic potential, clinicians should collect specimens depending on when the patient presents for care and their immunization history.

Mumps: Resurgence of a once-dormant disease

Mumps is a systemic viral illness, preventable by vaccination, that typically affects children and is characterized by unilateral or bilateral swelling of the parotid glands. Uncommon complications such as orchitis, oophoritis, deafness, pancreatitis, aseptic meningitis, and encephalitis occur more often in adults. Recent outbreaks of the disease appear to be caused by a failure to maintain herd immunity in certain populations, particularly in affluent white communities. This article reviews the clinical manifestations, diagnosis, and potential complications in patients with mumps.

Viral etiology of sporadic cases of parotitis among children in Korea during 2013-2014

Recent years have seen a high incidence of mumps, which is generally diagnosed based on clinical features, especially parotitis, without laboratory confirmation in Korea. To better understand the epidemiology of mumps in Korean children, we investigated sporadic suspected mumps cases with parotitis. In total, 237 buccal swabs or throat swabs collected from children with parotitis who had been clinically diagnosed with mumps were tested using real-time PCR for the detection of six viruses (Epstein-Barr virus, Human herpesvirus 6, Mumps virus, Human parainfluenza virus-1, -2, -3, Human adenovirus, Human bocavirus). Among 237 parotitis cases, 87 (36.7%) were positive for at least one virus; a single infection was observed in 73 (83.9%) cases, and co-infections were detected in 14 (16.1%) cases. Epstein-Barr virus was most frequent (20.7%), followed by human herpesvirus 6 (8.0%), mumps virus (5.5%), human parainfluenza virus-3 (4.6%), human adenovirus (4.2%), and human bocavirus (0.4%). These data suggested that the sporadic suspected mumps in the children might be related to other respiratory viruses rather than to the mumps virus. Our findings also indicate the limitation of clinical diagnosis without laboratory confirmation for mumps and thus highlight the importance of laboratory testing in suspected mumps cases.

Shift within age-groups of mumps incidence, hospitalizations and severe complications in a highly vaccinated population. Spain, 1998-2014

The mumps vaccine (Jeryl-Lynn-strain) was introduced in Spain in 1981, and a vaccination policy which included a second dose was added in 1995. From 1992-1999, a Rubini-strain based vaccine was administered in many regions but later withdrawn due to lack of effectiveness. Despite high levels of vaccination coverage, epidemics have continued to appear. We characterized the three epidemic waves of mumps between 1998 and 2014, identifying major changes in susceptible populations using Poisson regression. For the period 1998-2003 (P1), the most affected group was from 1 to 4years old (y) [Incidence Rate (IR)=71.7 cases/100,000 population]; in the periods 2004-2009 (P2) and 2010-2014 (P3) IR ratio (IRR) increased among 15-24y (P2=1.46; P3=2.68) and 25-34y (P2=2.17; P3=4.05). Hospitalization rate (HR), complication rate (CR) and neurological complication rate (NR) among hospitalized subjects decreased across the epidemics, except for 25-34y which increased: HR ratio (HRR) (P2=2.18; P3=2.16), CRR (P3=2.48), NRR (P3=2.41). In Spain mumps incidence increased, while an overall decrease of hospitalizations and severe complications occurred across the epidemics. Cohorts born during periods of low vaccination coverage and those vaccinated with Rubini-strain were the most affected populations, leading to a shift in mumps cases from children to adolescents and young adults; this also reveals the waning immunity provided by the mumps vaccine. Despite not preventing all mumps cases, the vaccine appears to prevent serious forms of the disease.

Saliva and viral infections

Over the last 10 years there have been only a handful of publications dealing with the oral virome, which is in contrast to the oral microbiome, an area that has seen considerable interest. Here, we survey viral infections in general and then focus on those viruses that are found in and/or are transmitted via the oral cavity; norovirus, rabies, human papillomavirus, Epstein‐Barr virus, herpes simplex viruses, hepatitis C virus, and HIV. Increasingly, viral infections have been diagnosed using an oral sample (e.g. saliva mucosal transudate or an oral swab) instead of blood or urine. The results of two studies using a rapid and semi‐quantitative lateral flow assay format demonstrating the correlation of HIV anti‐IgG/sIgA detection with saliva and serum samples are presented. When immediate detection of infection is important, point‐of‐care devices that obtain a non‐invasive sample from the oral cavity can be used to provide a first line diagnosis to assist in determining appropriate counselling and therapeutic path for an increasing number of diseases.

Mumps Outbreak Among a Highly Vaccinated University Community-New York City, January-April 2014

Background

On 14 January 2014, a vaccinated student presented with parotitis. Mumps immunoglobulin M (IgM) testing was negative and reverse-transcription polymerase chain reaction (RT-PCR) testing was not performed, resulting in a missed diagnosis and the start of an outbreak at a New York City (NYC) university.

Methods

Mumps case investigations included patient interviews, medical records review, and laboratory testing including mumps serology and RT-PCR. Case patients were considered linked to the outbreak if they attended or had epidemiologic linkage to the university. Epidemiologic, clinical, and laboratory data for outbreak cases residing in NYC were analyzed.

Results

Fifty-six NYC residents with mumps were identified with onset between 12 January and 30 April 2014. Fifty-three cases (95%) were university students, 1 (2%) was a staff member, and 2 (4%) had epidemiologic links to the university. The median age was 20 years (range 18-37 years). All cases had parotitis. Three cases were hospitalized, including 1 of 2 cases with orchitis. Fifty-four (96%) cases had received ≥1 mumps-containing vaccine, 1 (2%) was unvaccinated due to religious exemption, and 1 (2%) had unknown vaccination status. Two of the 44 (5%) cases tested by serology were mumps IgM positive, and 27 of the 40 (68%) tested by RT-PCR were positive.

Conclusions

Mumps outbreaks can occur in highly vaccinated populations. Mumps should be considered in patients with parotitis regardless of vaccination status. RT-PCR is the preferred testing method; providers should not rely on IgM testing alone. High vaccination coverage and control measures likely limited the extent of the outbreak.

Evaluation of a TaqMan Array Card for Detection of Central Nervous System Infections

Infections of the central nervous system (CNS) are often acute, with significant morbidity and mortality. Routine diagnosis of such infections is limited in developing countries and requires modern equipment in advanced laboratories that may be unavailable to a number of patients in sub-Saharan Africa. We developed a TaqMan array card (TAC) that detects multiple pathogens simultaneously from cerebrospinal fluid. The 21-pathogen CNS multiple-pathogen TAC (CNS-TAC) assay includes two parasites (Balamuthia mandrillaris and Acanthamoeba), six bacterial pathogens (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Mycoplasma pneumoniae, Mycobacterium tuberculosis, and Bartonella), and 13 viruses (parechovirus, dengue virus, Nipah virus, varicella-zoster virus, mumps virus, measles virus, lyssavirus, herpes simplex viruses 1 and 2, Epstein-Barr virus, enterovirus, cytomegalovirus, and chikungunya virus). The card also includes human RNase P as a nucleic acid extraction control and an internal manufacturer control, GAPDH (glyceraldehyde-3-phosphate dehydrogenase). This CNS-TAC assay can test up to eight samples for all 21 agents within 2.5 h following nucleic acid extraction. The assay was validated for linearity, limit of detection, sensitivity, and specificity by using either live viruses (dengue, mumps, and measles viruses) or nucleic acid material (Nipah and chikungunya viruses). Of 120 samples tested by individual real-time PCR, 35 were positive for eight different targets, whereas the CNS-TAC assay detected 37 positive samples across nine different targets. The CNS-TAC assays showed 85.6% sensitivity and 96.7% specificity. Therefore, the CNS-TAC assay may be useful for outbreak investigation and surveillance of suspected neurological disease.

Challenges in Interpretation of Diagnostic Test Results in a Mumps Outbreak in a Highly Vaccinated Population

In spite of a greatly reduced incidence rate due to vaccination, mumps outbreaks continue to occur in several areas of the world, sometimes in vaccinated populations. This article describes an outbreak in a highly vaccinated population in southwestern Ontario, Canada, and the challenges encountered in interpreting the results of diagnostic tests used in the outbreak. During the outbreak, patients were interviewed and classified according to the outbreak case definition, and specimens were collected for diagnostic testing according to Ontario guidelines. Twenty-seven individuals were classified as confirmed cases (n = 19) or suspect cases (n = 8) according to the case definition, only 9 of which were laboratory-confirmed cases: 7 confirmed by reverse transcriptase PCR (RT-PCR) and 2 by IgM serology. All 19 confirmed cases represented patients who were associated with secondary schools in the local area and had been vaccinated against mumps with one (n = 2) or two (n = 17) doses of the measles-mumps-rubella (MMR) vaccine. This is the first published report of an outbreak of mumps in Ontario in which all confirmed cases had been vaccinated against the disease. It highlights the limitations of and difficulties in interpreting current mumps diagnostic tests when used in vaccinated individuals.

Serological diagnosis of mumps: Value of the titration of specific IgG

INTRODUCTION

The aim of this study was to evaluate a cut-off point of the titration of IgG by ELISA in the diagnosis of mumps.

METHODS

A study was made of serum samples from 85 mumps cases (confirmed by PCR in saliva) and 2,351 controls of the general population of the Region of Madrid.

RESULTS

The IgM detection was positive in 21 cases (sensitivity of 24.7%). The best cut-off point corresponded to IgG titres ≥4,900 (sensitivity of 64.7% and specificity of 86.1%). Among 42 patients immunised with at least one dose of measles mumps, rubella vaccine IgM was detected in 4 cases. However, the detection of IgG ≥4,900 was positive in 29 (sensitivity of 69.0%).

CONCLUSIONS

An IgG result of ≥4.900 was almost 5 times more probable in a patient with mumps than in a non-infected patient. The detection of high titres of IgG against mumps could improve the IgM results in vaccinated people.

Releasing the Genomic RNA Sequestered in the Mumps Virus Nucleocapsid

In a negative-strand RNA virus, the genomic RNA is sequestered inside the nucleocapsid when the viral RNA-dependent RNA polymerase uses it as the template for viral RNA synthesis. It must require a conformational change in the nucleocapsid protein (N) to make the RNA accessible to the viral polymerase during this process. The structure of an empty mumps virus (MuV) nucleocapsid-like particle was determined to 10.4-Å resolution by cryo-electron microscopy (cryo-EM) image reconstruction. By modeling the crystal structure of parainfluenza virus 5 into the density, it was shown that the α-helix close to the RNA became flexible when RNA was removed. Point mutations in this helix resulted in loss of polymerase activities. Since the core of N is rigid in the nucleocapsid, we suggest that interactions between this region of the mumps virus N and its polymerase, instead of large N domain rotations, lead to exposure of the sequestered genomic RNA. IMPORTANCE Mumps virus (MuV) infection may cause serious diseases, including hearing loss, orchitis, oophoritis, mastitis, and pancreatitis. MuV is a negative-strand RNA virus, similar to rabies virus or Ebola virus, that has a unique mechanism of viral RNA synthesis. They all make their own RNA-dependent RNA polymerase (RdRp). The viral RdRp uses the genomic RNA inside the viral nucleocapsid as the template to synthesize viral RNAs. Since the template RNA is always sequestered in the nucleocapsid, the viral RdRp must find a way to open it up in order to gain access to the covered template. Our work reported here shows that a helix structural element in the MuV nucleocapsid protein becomes open when the sequestered RNA is released. The amino acids related to this helix are required for RdRp to synthesize viral RNA. We propose that the viral RdRp pulls this helix open to release the genomic RNA.

A Mumps Outbreak in Vojvodina, Serbia, in 2012 Underlines the Need for Additional Vaccination Opportunities for Young Adults

In 2012, mumps was introduced from Bosnia and Herzegovina to Vojvodina, causing an outbreak with 335 reported cases. The present manuscript analyses the epidemiological and laboratory characteristics of this outbreak, identifies its main causes and suggests potential future preventive measures. Sera of 133 patients were tested for mumps-specific antibodies by ELISA and 15 nose/throat swabs were investigated for mumps virus RNA by RT-PCR. IgG antibodies were found in 127 patients (95.5%). Mumps infection was laboratory-confirmed in 53 patients, including 44 IgM and 9 PCR positive cases. All other 282 cases were classified as epidemiologically-confirmed. More than half of the patients (n = 181, 54%) were 20–29 years old, followed by the 15–19 age bracket (n = 95, 28.4%). Twice as many males as females were affected (67% versus 33%). Disease complications were reported in 13 cases (3.9%), including 9 patients with orchitis and 4 with pancreatitis. According to medical records or anamnestic data, 190 patients (56.7%) were immunized with two doses and 35 (10.4%) with one dose of mumps-containing vaccine. The Serbian sequences corresponded to a minor genotype G variant detected during the 2011/2012 mumps outbreak in Bosnia and Herzegovina. Vaccine failures, the initial one-dose immunization policy and a vaccine shortage between 1999 and 2002 contributed to the outbreak. Additional vaccination opportunities should be offered to young adults during transition periods in their life trajectories.

Laboratory-based investigation of suspected mumps cases submitted to the German National Reference Centre for Measles, Mumps, and Rubella, 2008 to 2013

From 2008 to 2013, sample sets from 534 patients displaying clinical symptoms of mumps were submitted to the German Reference Centre for Measles, Mumps and Rubella. Mumps virus infection was confirmed in 216 cases (40%) by PCR and/or serology. Confirmed cases were more frequently seen in male than in female patients (128 vs. 81); the age group predominantly affected was 15 to 29 years old (65%, median age: 26.4 years). The majority of the confirmed cases had a remote history of vaccination with one or two doses of a mumps-containing vaccine (69%). Our results indicate that mumps virus caused two outbreaks in Bavaria in 2008 and 2010/2011 and a third one in Lower Saxony in 2011. Mumps virus genotype G was preponderantly detected from 2008 to 2013. For 107 of the 216 patients with a confirmed mumps infection, we correlated the results from PCR and serology. PCR detected cases during the first week after onset of symptoms (74% positive results). PCR worked best with throat swabs and oral fluids (61% and 60% positive results, respectively). IgM was more reliable with a longer time after onset of symptoms (67%), but indirect IgM serology was of insufficient sensitivity for vaccinated mumps cases (30%); the IgM μ-capture assay detected more cases in this group. Mumps virus is able to initiate an infection in vaccinated patients (secondary vaccine failure, SVF) although it is unclear to what extent. Since SVF does occur in highly vaccinated populations and IgM will not increase to detectable levels in all SVF patients, we strongly recommend using PCR plus serology tests to avoid false-negative diagnoses in vaccinated individuals with clinical signs of mumps.

[Clinical, epidemiological and etiological studies of adult aseptic meningitis: Report of 13 cases with mumps meningitis]

We experienced 13 cases (29.8 ± 7.0 years) of mumps meningitis and 365 cases of adult aseptic meningitis during 11 years from 2004 to 2014. A small epidemic of mumps occurred for 3-4 years, and the incidence rate of adult mumps meningitis coincided with the epidemic without seasonal fluctuation. Parotitis was observed in 8 of the 13 mumps meningitis patients (61.5%) and orchitis in 2 of 7 male patients (28.6%). There were no differences in clinical manifestations, laboratory findings, and outcome between patients with adult mumps meningitis and those with echovirus 9 meningitis (9 patients), except for the low frequency of nausea/vomiting and a high percentage of mononuclear cells of the cerebrospinal fluid in those with mumps. Eight patients had contact with persons with mumps before the symptomatic stage of meningitis. Only one patient had received mumps vaccination in childhood. On the basis of the values of the anti-mumps IgM and IgG antibodies, we speculated primary infection and the re-infection of mumps in 6 and 2 patients, respectively. Moreover, second vaccine failure was suggested in the vaccinated patient.

Vaccination in elite athletes

Public health vaccination guidelines cannot be easily transferred to elite athletes. An enhanced benefit from preventing even mild diseases is obvious but stronger interference from otherwise minor side effects has to be considered as well. Thus, special vaccination guidelines for adult elite athletes are required. In most of them, protection should be strived for against tetanus, diphtheria, pertussis, influenza, hepatitis A, hepatitis B, measles, mumps and varicella. When living or traveling to endemic areas, the athletes should be immune against tick-borne encephalitis, yellow fever, Japanese encephalitis, poliomyelitis, typhoid fever, and meningococcal disease. Vaccination against pneumococci and Haemophilus influenzae type b is only relevant in athletes with certain underlying disorders. Rubella and papillomavirus vaccination might be considered after an individual risk–benefit analysis. Other vaccinations such as cholera, rabies, herpes zoster, and Bacille Calmette–Guérin (BCG) cannot be universally recommended for athletes at present. Only for a very few diseases, a determination of antibody titers is reasonable to avoid unnecessary vaccinations or to control efficacy of an individual’s vaccination (especially for measles, mumps, rubella, varicella, hepatitis B and, partly, hepatitis A). Vaccinations should be scheduled in a way that possible side effects are least likely to occur in periods of competition. Typically, vaccinations are well tolerated by elite athletes, and resulting antibody titers are not different from the general population. Side effects might be reduced by an optimal selection of vaccines and an appropriate technique of administration. Very few discipline-specific considerations apply to an athlete’s vaccination schedule mainly from the competition and training pattern as well as from the typical geographical distribution of competitive sites.

Post-vaccine measles in a child with concomitant influenza, Sicily, Italy, March 2015

We describe the occurrence of measles in an 18 month-old patient in Sicily, Italy, in March 2015, who received the first dose of a measles-containing vaccine seven days before onset of prodromal symptoms. Measles virus infection was confirmed by PCR and detection of specific immunoglobulin; viral genotyping permitted the confirmation of a vaccine-associated illness. The patient had a concurrent influenza virus infection, during a seasonal epidemic outbreak of influenza.

Mumps outbreak and laboratory diagnosis

BACKGROUND

Several mumps outbreaks have been reported in Europe and in the United States among highly vaccinated populations. Biological diagnosis is classically based on the detection of mumps-specific IgM, but the ability of serological tests to confirm mumps infection seems to be limited among vaccinated patients.

OBJECTIVES

We aim to report a mumps outbreak in an engineering school in Grenoble, France, from February to June 2013 and results of the biological testing.

STUDY DESIGN

WHO definitions were used to define cases. Mumps--specific IgM and IgG were assessed by a commercially available EIA. Mumps RNA detection by real time reverse transcriptase polymerase chain reaction tests (RT-PCR) and mumps genotyping were performed by the French National Reference Centre for Paramyxoviridae.

RESULTS

Sixty two mumps patient-cases were identified using WHO case definitions, 20 being biologically explored, of which 17 were confirmed by biological tests. Vaccination status was documented for 27 patients/62: 4 (14.8%) patients had received one dose of MMR vaccine, and 23 (85.2) two doses of MMR vaccine. Among the biologically explored patients, 83% had a positive RT PCR at the first sampling whereas only 45% had positive or equivocal IgM. All the genotyped strains were genotype G.

CONCLUSIONS

Mumps laboratory diagnosis in a highly vaccinated population is challenging. Serological tests among vaccinated patients should be interpreted cautiously and confirmed by RT-PCR tests at the beginning of a mumps outbreak.