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.

Genomic Characterization of Three Canadian Mumps Outbreaks Demonstrates Endemic Transmission in Canada.

Despite the provision of a mumps vaccination program in Canada for over three decades, mumps has not reached elimination. Instead, a re-emergence has been observed in vaccinated populations, particularly in young adults. These outbreaks have been almost exclusively due to genotype G infections, a trend that has been seen in other countries with high mumps vaccination rates. To characterize mumps outbreaks in Canada, genomes from samples from Manitoba (n = 209), Newfoundland (n = 25), and Nova Scotia (n = 48) were sequenced and analysed by Bayesian inference. Whole genome sequencing was shown to be highly discriminatory for outbreak investigations compared to traditional Sanger sequencing. The results showed that mumps virus genotype G most likely circulated endemically in Canada and between Canada and the US. Overall, this Canadian outbreak data from different provinces and ancestral strains demonstrates the benefits of molecular genomic data to better characterize mumps outbreaks, but also suggests genomics could further our understanding of the reasons for potential immune escape of mumps genotype G and evolution in highly vaccinated populations. With a possible endemic circulation of mumps genotype G and the remaining risk of new imported cases, increased surveillance and alternative vaccination strategies may be required for Canada to reach the current target for mumps or a future elimination status.

Genetic characteristic of mumps virus from 2012 to 2016 and its serum antibody level among general healthy population during 2018-2020 in Jiangsu Province, China.

Mumps is a vaccine-preventable disease with high contagious capability. Its incidence declined rapidly since one dose of mumps vaccine was introduced into Expanded Program of Immunization (EPI) in 2008 in China. Nonetheless, the outbreaks of mumps remain frequent in China. Here we aim to assess herd immunity level followed by one-dose mumps ingredient vaccine and to elucidate the genetic characteristics of mumps viruses circulating in the post vaccine era in Jiangsu province of China. The complete sequences of mumps virus small hydrophobic(SH) gene were amplified and sequenced; coalescent-based Bayesian method was used to perform phylogenetic analysis with BEAST 1.84 software. Commercially available indirect enzyme-linked immune-sorbent IgG assay was used for the quantitative detection of IgG antibody against mumps virus. Our results show that genotype F was the predominant mumps viruses and belonged to indigenous spread, and most of Jiangsu sequences clustered together and formed a monophyly. The prevalence of mumps reached a peak in 2012 and subsequently declined, which presented an obvious different trajectory with virus circulating in other regions of China. The gene diversity of viruses circulating in Jiangsu province was far less than those in China. The antibody prevalence reached 70.42% in the general population during 2018 to 2020. The rising trend of antibody level was also observed. Although mumps antibody prevalence does not reach expected level, mumps virus faces higher pressure in Jiangsu province than the whole of China. To reduce further the prevalence of mumps viruses, two doses of mumps vaccine should be involved into EPI.

Molecular epidemiology of mumps viruses in the Netherlands, 2017-2019.

Mumps cases continue to occur, also in countries with a relatively high vaccination rate. The last major outbreaks of mumps in the Netherlands were in 2009-2012 and thereafter, only small clusters and single cases were reported. Molecular epidemiology can provide insights in the circulation of mumps viruses. The aims of the present study were to analyze the molecular epidemiology of mumps viruses in the Netherlands in 2017-2019 and to compare the phylogenetic trees built from sequence data of near complete mumps virus genomes or from the SH gene and non-coding regions (SH+NCRs). To this end, Sanger sequence data from SH+NCRs were analyzed from 82 mumps genotype G viruses. In addition, near complete genomes were obtained from 10 mumps virus isolates using next-generation sequencing. Analysis of SH+NCRs sequences of mumps genotype G viruses revealed the presence of two major genetic lineages in the Netherlands, which was confirmed by analysis of near complete genomes. Comparison of phylogenetic trees built with SH+NCRs or near complete genomes indicated that the topology was similar, while somewhat longer branches were present in the phylogenetic tree with near complete genomes. These results confirm that analysis of SH + NCRs sequence data is a useful approach for molecular surveillance. Furthermore, data from recent mumps genotype G viruses might indicate (intermittent) circulation of mumps genotype G viruses in the Netherlands in 2017-2019.

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.

Mumps: MMR vaccination and genetic diversity of mumps virus, 2007-2011 in Catalonia, Spain.

BACKGROUND: Mumps is a vaccine-preventable disease but outbreaks have been reported in persons vaccinated with two doses of MMR vaccine. The objective was to describe the demographic features, vaccination effectiveness and genetic mumps virus diversity among laboratory-confirmed cases between 2007 and 2011 in Catalonia. METHODS: Cases and outbreaks of mumps notified to the notifiable diseases system of Catalonia between 2007 and 2011 retrospectively registered were included. Public health care centres provided written immunization records to regional public health staff to determine the vaccination history. Saliva and serum specimens were collected from suspected cases for laboratory-confirmation using real-time reverse-transcriptase PCR (rtRT-PCR) or serological testing. Phylogenetic analysis of the complete SH gene (316 nucleotides) and complete coding HN protein (1749 nucleotides) sequences was made. Categorical variables were compared using the Chi-square or Fisher's tests and continuous variables using the Student test. Vaccination effectiveness by number of MMR doses was estimated using the screening method. RESULTS: During the study period, 581 confirmed cases of mumps were notified (incidence rate 1.6 cases/100,000 persons-year), of which 60% were male. Three hundred sixty-four laboratory-confirmed cases were reported, of which 44% were confirmed by rtRT-PCR. Of the 289 laboratory-confirmed cases belonging to vaccination cohorts, 33.5% (97) had received one dose of MMR vaccine and 50% (145) two doses. Based on phylogenetic analyses of 316-nucleotide and 174-nucleotide SH sequences, the viruses belonging to viral genotypes were: genotype G (126), genotype D (23), genotype H (2), genotype F (2), genotype J (1), while one remained uncharacterized. Amino acid differences were detected between circulating strains and the Jeryl Lynn vaccine strains, although the majority of amino acid substitutions were genotype-specific. Fifty-one outbreaks were notified that included 324 confirmed mumps cases. Genotype G was the most frequent genotype detected. The family (35%), secondary schools (25%) and community outbreaks (18%) were the most frequent settings. CONCLUSIONS: Our study shows that genotype G viruses are the most prevalent in Catalonia. Most cases occurred in people who had received two doses of MMR, suggesting inadequate effectiveness of the Jeryl Lynn vaccine strain. The possible factors related are discussed.

Identification and quantification of defective virus genomes in high throughput sequencing data using DVG-profiler, a novel post-sequence alignment processing algorithm.

Most viruses are known to spontaneously generate defective viral genomes (DVG) due to errors during replication. These DVGs are subgenomic and contain deletions that render them unable to complete a full replication cycle in the absence of a co-infecting, non-defective helper virus. DVGs, especially of the copyback type, frequently observed with paramyxoviruses, have been recognized to be important triggers of the antiviral innate immune response. DVGs have therefore gained interest for their potential to alter the attenuation and immunogenicity of vaccines. To investigate this potential, accurate identification and quantification of DVGs is essential. Conventional methods, such as RT-PCR, are labor intensive and will only detect primer sequence-specific species. High throughput sequencing (HTS) is much better suited for this undertaking. Here, we present an HTS-based algorithm called DVG-profiler to identify and quantify all DVG sequences in an HTS data set generated from a virus preparation. DVG-profiler identifies DVG breakpoints relative to a reference genome and reports the directionality of each segment from within the same read. The specificity and sensitivity of the algorithm was assessed using both in silico data sets as well as HTS data obtained from parainfluenza virus 5, Sendai virus and mumps virus preparations. HTS data from the latter were also compared with conventional RT-PCR data and with data obtained using an alternative algorithm. The data presented here demonstrate the high specificity, sensitivity, and robustness of DVG-profiler. This algorithm was implemented within an open source cloud-based computing environment for analyzing HTS data. DVG-profiler might prove valuable not only in basic virus research but also in monitoring live attenuated vaccines for DVG content and to assure vaccine lot to lot consistency.

Optimizing molecular surveillance of mumps genotype G viruses.

Mumps viruses continue to cause sporadic cases and outbreaks in countries with a high vaccination coverage for mumps. Molecular surveillance of mumps viruses can be supportive to elucidate the origin and transmission routes of mumps virus in case of an outbreak. Currently, molecular surveillance is worldwide primarily focused on sequencing of the small hydrophobic (SH) gene. However, few studies have already shown that additional genes or regions contribute to the resolution of the sequence data in such a way that mumps cases that seem to be linked to the same source on basis of the SH sequence, appear to be linked to another source or chain of transmission. Notably, this sequence information was recently extracted from the hemagglutinin-neuraminidase (HN) and fusion (F) genes (total 3364 nucleotides), or from the sum of the three non-coding regions (NCRs; total 1954 nt) between the nucleocapsid protein, phosphoprotein, matrix protein and F protein, but also from the complete genome. Here, sequence data from NCRs were compared with that of the HN and F gene, using mumps genotype G viruses detected in the Netherlands between 2010 and 2018. Results of this study indicate that NCRs sequence data provided similar or slightly better sequence resolution compared to the HN and F genes for most viruses. For molecular surveillance of currently circulating mumps genotype G viruses is sequencing of SH in combination with NCRs currently a useful approach.

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.

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.

Outbreak of mumps virus genotype G infection in tribal individuals during 2016-17 in India.

Tribal individuals presented with fever and uni- or bi-lateral parotitis in Galonda and Silli villages (Dadra and Nagar Haveli, India) between 2 October 2016 and 19 March 2017. Consequently, the magnitude and epidemiological characteristics of the outbreak were investigated. Overall, 139 cases of suspected mumps were identified in both the above villages. Most of the suspected cases were 5-15 years old, the exceptions being three adults who had no noticeable complications. Specimens were collected from 42 of the suspected cases and their close contacts (n = 39) for laboratory investigation. Mumps infection was laboratory-confirmed in 73.8% and 20.5% of the suspected cases and contacts, respectively. Mumps was confirmed in seven adults aged 17-42 years, including three suspected cases and four contacts. To the best of our knowledge, this is the first report of a complete virus genome circulating among tribal individuals. Sequencing and phylogenetic studies revealed circulation of mumps virus genotype G in these tribal villages with 99% identity to a mumps virus detected in the UK (1996) and Canada (2009). Comparison with Indian mumps viruses revealed 99% and 98% identity to previously reported isolates from Pune during 2012 and 1986, respectively. Although the outbreak was large, no major complications were reported in the tribal villages. Detection of asymptomatic mumps in numerous close contacts indicates the importance of laboratory investigations in an outbreak setting.

Genomic non-coding regions reveal hidden patterns of mumps virus circulation in Spain, 2005 to 2015.

BackgroundSince mumps vaccination was introduced in 1981 in Spain, the incidence of the disease has dropped significantly. However, cyclic epidemic waves and outbreaks still occur, despite high vaccination coverage. The World Health Organization (WHO) recommends genotyping to trace the pattern of mumps virus (MuV) circulation. Genotype H was predominant in Spain, but was replaced in 2005 by genotype G which has subsequently remained dominant. Of the small hydrophobic protein gene sequences, 78% are identical and belong to the MuVi/ Sheffield.GBR.1.05/[G]-variant. Aim: Our study aimed to investigate whether the circulation of MuV strains in Spain was continuous after the emergence of genotype G in 2005. Method: We obtained 46 samples from Spanish patients infected with MuVi/Sheffield.GBR.1.05/[G] during two epidemic waves and analysed them using new molecular markers based on genomic non-coding regions (NCRs) that discriminate subvariants of this virus strain. Results: Phylogenetic analyses of the nucleoprotein-phosphoprotein and matrix protein-fusion protein NCR indicated strain replacement after a drop in incidence in 2009, which had not been detectable by SH sequencing. Clustering of sequences from patients epidemiologically linked in the same outbreak suggests a potential use for these NCRs in outbreak characterisation. Conclusion: We suggest to consider their use in conjunction with the SH gene in the future WHO recommendations for MuV epidemiological surveillance.

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.

Mechanisms of temperature sensitivity of attenuated Urabe mumps virus.

Temperature sensitivity is a phenotype often associated with attenuation of viruses. Previously, we purified several mumps variants from an incompletely attenuated Urabe strain live attenuated vaccine. Here we characterize one isolate that is sensitive to growth at high temperature. This virus was attenuated in a small animal model of mumps virulence, and we identified unique coding substitutions in the hemagglutinin-neuraminidase (HN), the viral polymerase (L) gene, and a non-coding substitution close to the anti-genome promoter sequences. At the non-permissive temperature, transcription of viral mRNAs and production of the replication intermediate were reduced compared to events at the permissive temperature and to a non-ts virulent Urabe virus. As well, synthesis of viral proteins was also reduced at the higher temperature. While the actual sequence substitutions in the ts virus were unique, the pattern of substitutions in HN, L and genome end sequences is similar to another attenuated Urabe virus previously described by us.

Molecular Epidemiological Study of Mumps Epidemics of 2015 in Okinawa, Japan.

Although major mumps epidemics occurred every 4-5 years in Okinawa Prefecture in Japan, no laboratory diagnoses were conducted. A mumps epidemic started in Okinawa in October 2014, and we collected clinical samples from 31 patients in 4 areas (Hokubu, Nanbu, Miyako, and Yaeyama) from July to December 2015, for virus isolation and RT-PCR, whose positive ratios were 52% and 87%, respectively. Phylogenetic analyses showed that all isolates were classified into genotype G, and with one exception, consisted of 2 subgenotypes, Ge (55.6%) and Gw (40.7%), which have been prominent in Japan recently. One isolate was classified in another lineage, which was detected in Japan for the first time, and was similar to a Hong Kong isolate from 2014. Remarkably, the geographic distributions of the 2 major lineages were separated. The Ge viruses were isolated from the main island of Okinawa and the Yaeyama Islands, whereas the Gw isolates were mainly detected from the Miyako Islands. These results suggest that the Ge and Gw mumps viruses mainly caused the mumps epidemics of 2015 in Okinawa, and that they spread independently in separate regions. This is the first report describing the molecular epidemiology of mumps epidemics in Okinawa Prefecture.

Recombinant mumps viruses expressing the batMuV fusion glycoprotein are highly fusion active and neurovirulent.

A recent study reported the detection of a bat-derived virus (BatPV/Epo_spe/AR1/DCR/2009, batMuV) with phylogenetic relatedness to human mumps virus (hMuV). Since all efforts to isolate infectious batMuV have reportedly failed, we generated recombinant mumps viruses (rMuVs) in which the open reading frames (ORFs) of the fusion (F) and haemagglutinin-neuraminidase (HN) glycoproteins of an hMuV strain were replaced by the corresponding ORFs of batMuV. The batMuV F and HN proteins were successfully incorporated into viral particles and the resultant chimeric virus was able to mediate infection of Vero cells. Distinct differences were observed between the fusogenicity of rMuVs expressing one or both batMuV glycoproteins: viruses expressing batMuV F were highly fusogenic, regardless of the origin of HN. In contrast, rMuVs expressing human F and bat-derived HN proteins were less fusogenic compared to hMuV. The growth kinetics of chimeric MuVs expressing batMuV HN in combination with either hMuV or batMuV F were similar to that of the backbone virus, whereas a delay in virus replication was obtained for rMuVs harbouring batMuV F and hMuV HN. Replacement of the hMuV F and HN genes or the HN gene alone by the corresponding batMuV genes led to a slight reduction in neurovirulence of the highly neurovirulent backbone strain. Neutralizing antibodies inhibited infection mediated by all recombinant viruses generated. Furthermore, group IV anti-MuV antibodies inhibited the neuraminidase activity of bat-derived HN. Our study reports the successful generation of chimeric MuVs expressing the F and HN proteins of batMuV, providing a means for further examination of this novel batMuV.

[SH and HN Protein Genetic Characterization Analysis of Mumps Virus Isolated in Liaoning Province from 2008 to 2014].

To analyze the genetic characterization of epidemic mumps virus strains in Liaoning Province and provide the basis for mumps control. A total of 32 mumps viruses strains were isolated during 2008-2104. The fragment of SH genes and HN genes were amplified by RT-PCR, the PCR products were sequenced and analyzed. Basing on the 316 nucleotides of SH gene, The phylogenetic analyses were processed with the data of WHO mumps reference strains downloaded from GenBank and 32 mumps viruses strains. It showed that the 31 mumps virus strains belong to F genotype except MuVi/Liaoning. CHN/16.11 which was G genotype . Comparing to the A reference strains (Jeryl-Lynn and S-79), F genotype MuV were mutated on 12 amino acids sites and 27 amino acids siteson on HN gene. F genotype MuV added one N-glycosylation site in 464th-466th amino acids. The antigenic sites on HN were mutated on 121th, 123th, 279th, 287th, 336th, 356th and 442th. Maybe, it will influence the MuV antigenic.

Mumps in the Czech Republic in 2013: Clinical Characteristics, Mumps Virus Genotyping, and Epidemiological Links.

AIM: The aim of the study was to map the incidence of mumps in the Czech Republic in terms of clinical symptoms, epidemiological links, and characteristics of circulating genotypes. METHODS: Patients with suspected mumps examined in the Infectious Diseases Clinic of the Na Bulovce Hospital in 2013 were enrolled in the study. Buccal swab specimens were tested by means of nucleic acid detection (RT-qPCR) and when positive, they were cultured in tissue culture. Sequencing was carried out using the BigDye Terminator v3.1 Cycle Sequencing Kit and Genetic Analyzer 3500. The SeqScape software was used for the analysis of sequencing data and filtering out low quality reads. The phylogenetic analysis and genotyping were performed using the Mega 6 software. To generate the phylogenetic tree, all sequences were aligned by the MAFFT tool and the alignment obtained was edited using the BioEdit software. In all patients, selected biochemical markers (C-reactive protein, white blood cell count and serum amylase) were measured. The EPIDAT system used for reporting infectious diseases, record keeping, and data analysis in the Czech Republic was the source of statistical data. RESULTS: Eighty-nine patients with suspected mumps were examined in the Na Bulovce Hospital and 65 of them were laboratory confirmed with mumps: 40 males (61.5%) and 25 females (38.5%). The mean age of the study cohort was 25.9 years (median age of 23 years, age range from 10 to 73 years) and 14 patients were under 18 years of age. Thirty-four (52.3%) patients were vaccinated in childhood, 28 (43.1%) were unvaccinated, and for three persons, vaccination data were not available. A severe course of the disease was reported in 15 (23.1%) patients. Fourteen of them needed hospitalization because of orchitis (9 males) and meningitis (5 patients). One patient with orchitis was treated on an outpatient basis. The need for hospitalization tended to be lower in the unvaccinated patients (14.7% vs. 35.7%, p=0.076). In 2013, 1,553 cases of mumps were reported to the EPIDAT system. Of these, 640 were laboratory confirmed. The most often reported complications were orchitis (90 cases, i.e. 10.3%) and meningitis (21 cases, i.e. 1.4%). Orchitis was diagnosed in 30.3% of the unvaccinated and in 6.4% of the vaccinated males. Meningitis occurred in 3.1% of the unvaccinated and in 1.0% of the vaccinated patients. CONCLUSION: Despite the emergence of mumps among the vaccinated population, the present study has confirmed a positive effect of the vaccine, particularly on the incidence of complications and inflammatory markers. All 30 sequenced mumps virus strains were assigned to group G. A secondary vaccine failure due to waning immunity seems to be a plausible explanation for the rise in mumps cases.

Genetic characteristics of mumps viruses isolated in Korea from 2007 to 2012.

Mumps is a vaccine-preventable viral disease. Despite vaccine coverage of >95%, the incidence of mumps has increased in Korea since 2007. This study aimed to genetically characterize mumps virus (MuV) strains that circulated in Korea between 2007 and 2012 to determine the factors underlying mumps outbreaks. MuV was isolated from 175 clinical specimens between 2007 and 2012 in Korea. Upon analysis of the SH gene in Korean mumps virus isolates, three different genotypes were identified: I, H, and F. The MuV genotypes I and H co-circulated in Korea, and eight isolates of Korean genotype F were found within the same time period in 2008. An analysis of HN amino-acid sequence data showed that Korean isolates had no changes in their glycosylation sites. At putative neutralizing epitope sites, the Jeryl-Lynn strain showed 4-5 different amino acid sequences from those observed in Korean isolates. Korean isolates of genotypes I and H shared distinctive point mutations on putative neutralizing epitope positions in each genotype. This report describes the genetic characteristics of MuV strains circulating in Korea and provides information on endemic mumps infections. This information may be important to help prevent mumps and control outbreaks of mumps in Korea. J. Med. Virol. 88:1479-1486, 2016. © 2016 Wiley Periodicals, Inc.

Detection of mumps virus genotype H in two previously vaccinated patients from Mexico City.

Infections caused by mumps virus (MuV) have been successfully prevented through vaccination; however, in recent years, an increasing number of mumps outbreaks have been reported within vaccinated populations. In this study, MuV was genotyped for the first time in Mexico. Saliva samples were obtained from two previously vaccinated patients in Mexico City who had developed parotitis. Viral isolation was carried out in Vero cells, and the SH and HN genes were amplified by RT-PCR. Amplicons were sequenced and compared to a set of reference sequences to identify the MuV genotype.