Mumps Cases Research Articles

Mumps epidemic dynamics in the United States before vaccination (1923–1932)

Mumps is a vaccine-preventable, reemerging, and highly transmissible infectious disease. Widespread vaccination dramatically reduced cases; however, case counts have been increasing over the past 20 years. To provide a quantitative overview of historical mumps dynamics that can act as baseline information to help identify causes of mumps reemergence, we analyzed timeseries of cases reported from 1923 to 1932 in the United States. During that time, 239,230 mumps cases were reported in 70 cities. Larger cities reported annual epidemics and smaller cities reported intermittent, sporadic outbreaks. The critical community size above which transmission continuously occurred was likely between 365,583 and 781,188 individuals but could range as high as 3,376,438 individuals. Mumps cases increased as city size increased, suggesting density-dependent transmission. Using a density-dependent SEIR model, we calculated a mean effective reproductive number (Re) of 1.2. Re varied by city and over time, with periodic high values that could characterize short periods of very high transmission known as superspreading events. Case counts most often peaked in March, with higher-than-average transmission from December through April and showed a correlation with weekly births. While certain city pairs in Midwestern states had synchronous outbreaks, most outbreaks were less synchronous and not driven by distance between cities. This work demonstrates the importance of long-term infectious disease surveillance data and will inform future studies on mumps reemergence and control.

Mumps resurgence in a highly vaccinated population: Insights gained from surveillance in Canada, 2002–2020

Although mumps vaccination has been routine in Canada for decades, mumps cases and outbreaks continue to occur periodically. Mumps surveillance, including monitoring of the mumps virus genotype associated with disease activity, is important to document baseline activity and to advance further research into vaccine effectiveness. Here we describe a detailed analysis of mumps cases that have been detected in Canada from 2002 to 2020, with a focus on the mumps molecular epidemiology. In total, 7395 cases of mumps were reported to the surveillance system, with outbreaks occurring in the years 2007, 2010 and 2016 to 2018. Adolescents and young adults aged 15 to 29 years had the highest risk of being a case (rate ratios ranging from 1.50 to 2.29), compared to adults aged 30 to 39. Genotypes of mumps viruses were determined in 3225 specimens. Genotype G was predominantly detected (96% of genotyped specimens) and was first reported in 2005. Other genotypes were more likely to be detected in cases that also reported travel (or were linked to imported cases) than the cases with genotype G detected (p < 0.0001). The genotype G viruses had little sequence diversity in the 316 nucleotide window used for genotyping (the small hydrophobic protein gene) and mainly belonged to a single phylogenetic lineage that included the MuVi/Sheffield.GBR/1.05 reference sequence. The analysis of over ten years of data has demonstrated that mumps genotype G, specifically belonging to a single lineage, the Sheffield lineage, is the endemically circulating virus in Canada. This lineage is seen also in other countries using the genotype A vaccine. Mumps remains endemic despite high MMR vaccination coverage which has been sufficient to eliminate circulation of measles and rubella in Canada, raising the hypothesis of the evolution towards a vaccine escape mumps virus.

Mumps in Poland in 2020.

Mumps is an acute, generalized viral disease whose source of infection is the infected person. In 2003, vaccination against mumps became compulsory in Poland, performed according to a twodose scheme. The combined MMR vaccine (against measles, mumps and rubella) was introduced as part of the Protective Vaccination Program (PVP), which influenced the number of cases in Poland. The aim of the study was to evaluate the epidemiological indicators of mumps in Poland in 2020 compared to previous years. The analysis of the epidemiological situation of mumps in Poland in 2020 was based on the interpretation of data from the bulletin "Infectious diseases and poisonings in Poland in 2020" and "Vaccinations in Poland in 2020". In 2020, 582 cases of mumps were registered in Poland. The total incidence was 1.5 per 100,000 inhabitants and was lower compared to 2019. The highest incidence was 2.0 per 100,000 inhabitants were registered in the Świętokrzyskie Voivodeship and the lowest - 0.7 in the Dolnośląskie Voivodeship. The highest incidence (24.6/100,000) was recorded in children aged 5-9 years. The incidence of men (1.8/100,000) was higher than that of women (1.2/100,000). In 2020, 6 patients were hospitalized in Poland due to mumps, which was less than in 2019 (22 patients). The level of vaccination against mumps in children aged 3 was lower by 0.7 percentage points compared to 2019 and amounted to 91.9% across Poland. In 2020, there was a decrease in the number of mumps cases compared to the previous year. The lower incidence may have been the result of a reduction in mumps virus transmission due to a change in population health behavior during the COVID-19 pandemic. Due to the epidemiological threat, the functioning of nurseries, kindergartens and schools was also temporarily suspended, which resulted in a reduction in the incidence of mumps in younger age groups, which are the main group of patients.

Mumps virus (Paramyxoviridae: &lt;i&gt;Orthorubulavirus: Mumps orthorubulavirus&lt;/i&gt;) genotyping as a component of laboratory confirmation of infection

Mumps is a viral infection of high social significance. National program Elimination of measles and rubella and achievement of a stable sporadic incidence of epidemic mumps in the Russian Federation (20212025) sets the aim of gradual integration of mumps surveillance into the existing measles and rubella surveillance system. One of the key components of surveillance system is a laboratory confirmation of mumps cases. There are two approaches for laboratory confirmation of mumps cases, based on serological or molecular genetic methods. The aim of the work is molecular genetic characteristic of the mumps viruses (MuVs) circulated in the Russian Federation in 2022. Samples of swabs from the inner surface of the cheek of 11 patients with mumps were collected for the study. Viral RNA was isolated directly from the samples. The isolated RNA was used as a matrix for RT-PCR. PCR products were sequenced using the Sanger method, and phylogenetic analysis was performed using the MEGA-X software. The MuV genotype G was detected in all samples. Phylogenetic analysis showed the presence of two virus genetic groups G-1 and G-2 that were significantly different from the viruses circulating in other countries. The identification of two MuV genetic groups in a limited area suggests a high genetic diversity of the pathogen.

Viral detection from negative mumps cases with respiratory symptoms in Gwangju, South Korea in 2021.

Mumps is the second-most reported infectious disease in South Korea; however, due to the low pathogen confirmation rate in laboratory diagnoses, we proposed a method for reevaluating the high incidence rate via the laboratory verification of other viral diseases. In 2021, 63 cases of pharyngeal or cheek mucosal swabs of suspected mumps cases in Gwangju, South Korea, were assessed for causative pathogens using massive simultaneous pathogen testing. More than one respiratory virus was detected in 60 cases (95.2%), 44 (73.3%) of which were co-detected. Human rhinovirus was detected in 47 cases, followed by human herpesvirus (HHV)6 in 30; HHV4 (17), human bocavirus (17), HHV5 (10), and human parainfluenza virus 3 (6) were also detected. Our findings suggest the need for further investigations on the pathogenesis of diseases mimicking mumps, which are considered to aid with appropriate public health responses, treatment, and the prevention of infectious disease outbreaks. This article is protected by copyright. All rights reserved.

Clinical profile of mumps in children in a tertiary care hospital in Kashmir

Background Mumps is one of the oldest human illnesses known to humans. Mumps is caused by a paramyxovirus, which is a single-strand RNA virus. Mumps is characterized by painful, unilateral, or bilateral swelling of the salivary glands, in particular, the parotid glands. Methods: This is a hospital-based prospective observational study. All children of age ≤18 years, both males and females with acute onset of unilateral or bilateral tender, self-limited swelling of the parotid or other salivary gland without other apparent cause. Results: Of the 150 clinically diagnosed mumps cases, 87 (58%) were male and 63 (42%) were female (male-to-female ratio of 1.4:1). There was no case below 1 year but there were 40 cases between 1 and 5 years. The 40% belonged to the lower middle class of socioeconomic status as per Kuppuswamy’s scale, followed by the upper-middle and lower-middle class. Only 15 patients (10%) were completely immunized whereas the immunization status of 8% patients was not known, and the rest of the patients were non immunized (82%). Fever was the most common presentation (150 patients;100%), followed by parotid involvement. Parotitis was present in 146 (97.3%) cases at some point during the illness, 36 patients (24%) had unilateral and 110 patients (73.3%) had bilateral involvement. 16% of patients had multiple salivary gland involvement. Mean duration of illness was 9.0±2 days. Conclusions: Mumps is a significant public health problem to warrant investment in prevention through vaccination.

Anesthesia mumps: a case report

A 25 years old pregnant woman had a painful labor in her 38th week of pregnancy. Because of a previous delivery by a cesarean section, she underwent a second cesarean section. Her past medical and family history was unimportant. We performed the surgery under spinal anesthesia. The surgery was uneventful and the baby was in a good health. After 9 hours of surgery, she complained of painless swelling in the parotid glands. Physical examination and laboratories were normal. We started rehydration with normal saline and one dose of hydrocortisone (100 mg IV route). Close monitoring showed no problems in swallowing or any purulent discharge. Two days later, we had a complete resolution of the swelling. We discharged the woman with her child with no complaints. Our case is one of the rare cases of anesthesia mumps after spinal anesthesia. Physicians should be careful in considering such rare cases. Early diagnosis and management is the key.

Disentangling the causes of mumps reemergence in the United States

Over the past two decades, multiple countries with high vaccine coverage have experienced resurgent outbreaks of mumps. Worryingly, in these countries, a high proportion of cases have been among those who have completed the recommended vaccination schedule, raising alarm about the effectiveness of existing vaccines. Two putative mechanisms of vaccine failure have been proposed as driving observed trends: 1) gradual waning of vaccine-derived immunity (necessitating additional booster doses) and 2) the introduction of novel viral genotypes capable of evading vaccinal immunity. Focusing on the United States, we conduct statistical likelihood-based hypothesis testing using a mechanistic transmission model on age-structured epidemiological, demographic, and vaccine uptake time series data. We find that the data are most consistent with the waning hypothesis and estimate that 32.8% (32%, 33.5%) of individuals lose vaccine-derived immunity by age 18 y. Furthermore, we show using our transmission model how waning vaccine immunity reproduces qualitative and quantitatively consistent features of epidemiological data, namely 1) the shift in mumps incidence toward older individuals, 2) the recent recurrence of mumps outbreaks, and 3) the high proportion of mumps cases among previously vaccinated individuals.

Epidemiology of mumps, mumps complications, and mumps orchitis in Korea using the National Health Insurance Service database.

To analyze the presentation of mumps and mumps orchitis using the National Health Insurance Service Database (NHISD). Using information from the NHISD representing all cases of mumps in Korea, data regarding mumps orchitis were analyzed. The International Classification of Diseases, Tenth Revision, and Clinical Modification codes were used for diagnosis. The incidence estimates of the number of mumps cases were analyzed using the Statistical Analysis System (SAS) software. Based on the NHISD, 199,186 people were diagnosed with mumps, and males accounted for 62.3% cases. Teen males accounted for 69,870 cases, the largest number of patients diagnosed with mumps. The annual incidence of mumps increased every year (poisson regression, hazard ratio [HR] 1.026, 95% confidence interval [CI] 1.024-1.027; p<0.025). The risk of mumps was lower in females than that in males (poisson regression, HR 0.594, 95% CI 0.589-0.599; p<0.001). Of the 199,186 patients diagnosed with mumps, 3,872 patients (1.9%) had related complications. Among the mumps complications, the most diagnosed complication was mumps orchitis, which was seen in 41.8% of the males. Mumps orchitis cases accounted for less than 1.5% of the patients with mumps in minors under the age of 20 years and was somewhat higher in 2009 and 2013-2015. Among the complications related to mumps, meningitis was most common in females, while orchitis was dominant in males. Mumps orchitis also shows periodic outbreaks but is particularly prevalent in adults, which suggests the potential need for additional vaccination against mumps.

Mumps-specific IgG, IgG subclasses and neutralization titres to the vaccine and outbreak mumps strains differ in vaccinated healthy controls, breakthrough mumps infection cases and naturally infected individuals.

Despite widespread use of the mumps vaccine resulting in significant reduction in the incidence of symptomatic mumps infection, large outbreaks continue to occur in highly vaccinated populations. We examined the mumps-specific IgG, IgG subclasses and neutralization titres to the outbreak Genotype G5 and Jeryl Lynn vaccine (Genotype A) mumps strains. Sera from 207 individuals were classified into five distinct cohorts: healthy controls and mumps cases of 5-17 years and 18-25 years, and naturally infected individuals of 50+ years. Mumps specific IgG and IgG subclass levels were measured using modified ELISA assays with lysates and nucleoprotein antigens from both the mumps vaccine and circulating Genotype G5 strains. All sera were investigated for in vitro neutralizing antibody titres (GMT) using focus reduction neutralization assays. Data was analysed using the Kruskal-Wallis test and pairwise Wilcoxon tests. Mumps cases had higher mumps IgG levels compared to controls, to both the vaccine and outbreak strains, however levels decreased with age. Mumps IgG3 levels were significantly raised in mumps cases (p<0.001). Neutralization titres were lower to the outbreak strain in all cohorts with titres markedly lower in the mumps cohorts compared to healthy controls. Mean GMT to the vaccine strain increased with age. The naturally infected group displayed the highest GMT to the JL vaccine and the lowest GMT to the outbreak strain. Antigenic differences between mumps vaccine strain and circulating mumps viruses decrease the cross-neutralization capacity of vaccine-induced antibodies which may play a role in breakthrough infection.

Measles, Mumps, Rubella Vaccine (PRIORIX): Recommendations of the Advisory Committee on Immunization Practices - United States, 2022.

Vaccination is the main means for preventing measles, mumps, and rubella virus infections and their related complications (1,2). Achieving and maintaining high 2-dose measles, mumps, and rubella vaccination coverage in the United States has led to elimination of endemic measles in 2000, rubella and congenital rubella syndrome in 2004, and a sharp decrease in mumps cases. However, measles and rubella remain endemic in many countries, leading to importations of cases and occasional local transmission within the United States (3). Reported U.S. mumps cases declined >99% from the prevaccine period (4); however, mumps is endemic worldwide, and since 2006, the number of mumps cases and mumps outbreaks has increased in the United States, with wider geographic spread since 2016 (4). Given the risk for importation of measles and rubella and the resurgence of mumps, maintaining high measles, mumps, and rubella (MMR) vaccination coverage is important. Since 1978, only one MMR vaccine, M-M-R II (Merck and Co., Inc.), has been available in the United States. On June 6, 2022, the Food and Drug Administration approved a second MMR vaccine, PRIORIX (GlaxoSmithKline Biologicals), for the prevention of measles, mumps, and rubella in persons aged ≥12 months. The three live attenuated viruses contained in PRIORIX are genetically similar or identical to the corresponding components in M-M-R II (Table) (5-7). On June 23, 2022, the Advisory Committee on Immunization Practices (ACIP) unanimously recommended PRIORIX as an option to prevent measles, mumps, and rubella according to the existing recommended schedules and for off-label uses (i.e., indications not included in the package insert)* (1,2). ACIP considered PRIORIX to be safe, immunogenic, and noninferior to M-M-R II. Both PRIORIX and M-M-R II are fully interchangeable for all indications for which MMR vaccination is recommended. This report contains ACIP recommendations specific to PRIORIX and supplements the existing ACIP recommendations for MMR use (1,2).

Age-specific transmission dynamic of mumps: A long-term large-scale modeling study in Jilin Province, China.

Despite the adoption of a new childhood immunization program in China, the incidence of mumps remains high. This study aimed to describe the epidemiological characteristics of mumps in Jilin Province from 2005 to 2019 and to assess the transmissibility of mumps virus among the whole population and different subgroups by regions and age groups. The Non-age-specific and age-specific Susceptible-Exposed-Pre-symptomatic-Infectious-Asymptomatic-Recovered (SEPIAR) models were fitted to actual mumps incidence data. The time-varying reproduction number (R t ) was used to evaluate and compare the transmissibility. From 2005 to 2019, a total of 57,424 cases of mumps were reported in Jilin Province. The incidence of mumps was the highest in people aged 5 to 9 years (77.37 per 100,000). The two SEPIAR models fitted the reported data well (P < 0.01). The median transmissibility (R t ) calculated by the two SEPIAR models were 1.096 (range: 1.911 × 10-5-2.192) and 1.074 (range: 0.033-2.114) respectively. The age-specific SEPIAR model was more representative of the actual epidemic of mumps in Jilin Province from 2005-2019. For mumps control, it is recommended that mumps-containing vaccines (MuCV) coverage be increased nationwide in the 5-9 years age group, either by a mumps vaccine alone or by a combination of vaccines such as measles-mumps-rubella (MMR) vaccine. The coverage of vaccines in Jilin Province should be continuously expanded to establish solid immunity in the population. China needs to redefine the optimal time interval for MuCV immunization.

A Multi-Age-Group Interrupted Time-Series Study for Evaluating the Effectiveness of National Expanded Program on Immunization on Mumps.

The national Expanded Program on Immunization (EPI) in China has covered vaccines for measles, mumps, and rubella, among children aged 18–24 months since September 2008. However, no previous studies have quantified the effectiveness of the EPI on mumps incidence. There are methodological challenges in assessing the effect of an intervention that targets a subpopulation but finally influences the whole population. In this study, monthly data on mumps incidence were collected in Guangzhou, China, during 2005–2019. We proposed a multi-age-group interrupted time-series design, setting the starting time of exerting effect separately for 14 different age groups. A mixed-effects quasi-Poisson regression was applied to analyze the effectiveness of the EPI on mumps incidence, after controlling for long-term and seasonal trends, and meteorological factors. The model also accounted for the first-order autocorrelation within each age group. Between-age-group correlations were expressed using the contact matrix of age groups. We found that 70,682 mumps cases were reported during 2005–2019, with an annual incidence rate of 37.91 cases per 100,000 population. The effect of EPI strengthened over time, resulting in a decrease in the incidence of mumps by 16.6% (EPI-associated excess risk% = −16.6%, 95% CI: −27.0% to −4.7%) in September 2009 to 40.1% (EPI-associated excess risk% = −40.1%, 95% CI: −46.1% to −33.3%) in September 2019. A reverse U-shape pattern was found in age-specific effect estimates, with the largest reduction of 129 cases per 100,000 population (95% CI: 14 to 1173) in those aged 4–5 years. The EPI is effective in reducing the mumps incidence in Guangzhou. The proposed modeling strategy can be applied for simultaneous assessment of the effectiveness of public health interventions across different age groups, with adequate adjustment for within- and between-group correlations.

Management and Control Issues Related to Two Mumps Outbreaks in Houston: Future Implications.

Mumps is a highly contagious disease spread by airborne droplets, making control especially difficult in congregate, crowded settings such as shelters and jails. A mumps outbreak in Honduras, starting in 2018 among adults who were unvaccinated, spread northward with Central Americans migrating to the United States. We describe 2 mumps outbreaks in Houston during 2019 among migrants at the Houston Contract Detention Facility (HCDF) and among inmates at the Harris County Jail (HCJ). We investigated cases of acute onset parotitis. Three or more mumps cases in a facility was considered an outbreak. Confirmed cases had positive polymerase chain reactions (PCR). Probable cases were linked epidemiologically to a confirmed case in the same unit and a positive serology for serum anti-mumps immunoglobulin M (IgM) antibody. Outbreak control measures included enhanced surveillance, isolation of housing units, educational outreach, and immunization with Measles, Mumps, Rubella (MMR) vaccine. At HCDF, during a 10-month period, we investigated 42 possible cases. Of the possible cases, 28 were lab-confirmed with 9 probable, 4 ruled out, and 1 vaccine reaction. All were migrants. At HCJ, during a 3-month period, we investigated 60 suspect cases; 20 cases were lab-confirmed, 13 probable and 27 ruled out. All but 2 were inmates. Only about a third of those offered MMR vaccination accepted. Successful outbreak resolution required close cooperation with HCDF and HCJ with ongoing surveillance, isolation of units with cases and MMR vaccination. Such facilities will have outbreaks; regular communications with local public health could improve response.

Cost-effectiveness analyses of monovalent mumps vaccination programs for Japanese children

BackgroundThe most common preventative measure against mumps is vaccination with mumps vaccine. Over 122 countries have implemented mumps vaccine routine immunization programs, mostly via Measles-Mumps-Rubella (MMR) vaccine. In Japan, the unexpectedly high incidence of aseptic meningitis caused by mumps vaccine led to the discontinuation of the MMR national vaccination program in 1993, inadvertently resulting in the re-emergence of mumps. Plans of introducing monovalent mumps vaccine into routine vaccination schedule have become one of the emerging topics in health policy that has warranted the need in evaluating its value for money. MethodsWe conducted cost-effectiveness analyses with Markov model and calculated incremental cost-effectiveness ratios (ICERs) of two different vaccination programs (a single-dose program at one-year-old, a two-dose program with second dose uptakes at five) compared to status quo from both payers’ and societal perspectives. Transition probabilities and utility weights in estimating quality-adjusted life-year (QALY), and disease treatment costs were either estimated or obtained from literature. Costs per vaccination were assumed at ¥6140 (US$58;1US$ = ¥106). ResultsBoth programs reduce disease treatment costs compared to status quo, while the reduction cannot offset vaccination cost. ICER of either program is found to be under ¥5,000,000 (US$47,170)/QALY willingness-to-pay (WTP) threshold from either perspective. Results of probabilistic sensitivity analyses expressed by net monetary benefit indicated that at the WTP threshold, the acceptability is at 92.6% for two-dose vaccination program, 0% for single-dose vaccination program, and 7.4% for current no vaccination program. Two-dose program was optimal among the alternatives. One-way sensitivity analyses revealed that proportion of mumps-related hearing loss among mumps cases and vaccine effectiveness (VE) were key variables in changing the ICERs. ConclusionRoutine vaccination program of single- and two-dose programs were cost-effective from both payers’ and societal perspectives. Between the two, the two-dose vaccination program was observed to be more favorable.

Interactive Effects of meteorological Factors and Ambient air Pollutants on Mumps Incidences in Ningxia, China Between 2015 and 2019

Background: Existing evidence suggests that mumps epidemics, a global public health issue, are associated with meteorological factors and air pollutants at the population scale. However, the interaction effect of meteorological factors and air pollutants on mumps remains underexplored.Methods: Daily cases of mumps, meteorological factors, and air pollutants were collected in Ningxia, China, from 2015 to 2019. First, a distributed lag nonlinear model (DLNM) was employed to assess the confounding-adjusted relationship between meteorological factors, ambient air pollutants, and mumps incidences. According to the results of DLNM, stratification in both air pollutants and meteorological factors was adopted to further explore the interaction effect of particulate matter less than or equal to 2.5 μm in aerodynamic diameter (PM2.5) and ground-level ozone (O3) with temperature and relative humidity (RH).Results: We reported significant individual associations between mumps incidences and environmental factors, including temperature, relative humidity, PM2.5, and O3. Evident multiplicate and additive interactions between meteorological factors and PM2.5 were found with interaction relative risk (IRR) of 1.14 (95%CI: 1.01, 1.29) and relative excess risk due to interaction (RERI) of 0.17 (95%CI: 0.02, 0.32) for a moderate level of temperature at 12°C, and IRR of 1.37 (95%CI: 1.14, 1.66), RERI of 0.36 (95%CI: 0.11, 0.60) for a high level of temperature at 20°C, respectively. These results indicated that PM2.5 and temperature have a significant synergistic effect on the cases of mumps, while no interaction between relative humidity and PM2.5 is observed. Regarding O3 and meteorological factors (temperature = 12°C, 20°C), IRR and RERI were 1.33 (95%CI: 1.17, 1.52) and 0.30 (95%CI: 0.16, 0.45), 1.91 (95%CI: 1.46, 2.49) and 0.69 (95%CI: 0.32, 1.07), respectively. And IRR of 1.17 (95%CI: 1.06, 1.29), RERI of 0.13 (95%CI: 0.04, 0.21) for a middle level of relative humidity at 48%.Conclusion: Our findings indicated that meteorological factors and air pollutants imposed a significantly lagged and nonlinear effect on the incidence of mumps. The interaction between low temperature and O3 showed antagonistic effects, while temperature (medium and high) with PM2.5 and O3 presented synergistic effects. For relative humidity, the interaction with O3 is synergistic. These results provide scientific evidence to relevant health authorities for the precise disease control and prevention of mumps in arid and semi-arid areas.

Impact of vaccine effectiveness and coverage on preventing large mumps outbreaks on college campuses: Implications for vaccination strategy

Recent mumps outbreaks among highly vaccinated populations, including college students, have called into question the vaccine effectiveness (VE) of routine two-dose measles, mumps, and rubella (MMR2) immunization. We aimed to estimate the VE required for a novel vaccination strategy (e.g., MMR booster dose, novel vaccine) to prevent large mumps outbreaks on college campuses. Using mumps college outbreak data reported to the U.S. Centers for Disease Control and Prevention during 2016–2017, we estimated current MMR2 VE using the screening method and implemented a compartmental model of mumps transmission. We performed 2000 outbreak simulations, following introduction of an infectious person to a population of 10,000, over ranges of MMR2 vaccine coverage (VC) and VE (30.0–99.0%). We compared the impact of varying VC and VE on mumps and mumps orchitis case counts and determined VE thresholds that ensured < 5.0% and < 2.0% of the outbreak simulations exceeded 20 and 100 mumps cases. Median estimated MMR2 VE in reported mumps outbreaks was 60.5% and median reported MMR2 VC was 97.5%. Simulated mumps case count was more sensitive to changes in VE than in VC. The opposite was true for simulated mumps orchitis case count, though orchitis case count was small (mean <10 cases across simulations for VE near 60.5% and VC near 97.5%). At 97.5% VC, 73.1% and 78.2% VE were required for < 5.0% and < 2.0% of outbreaks, respectively, to exceed 100 mumps cases. Maintaining 97.5% VC, 82.4% and 85.9% VE were required for < 5.0% and < 2.0% of outbreaks, respectively, to exceed 20 cases. We conclude that maintaining current levels of MMR2 VC, a novel vaccination strategy aimed at reducing mumps transmission must achieve at least 73.1–85.9% VE among young adults to prevent large mumps outbreaks on college campuses.

Assessment of mumps-containing vaccine effectiveness by dose during 2006 to 2020 in Quzhou, China

ABSTRACT Mumps cases were reported frequently when a routine dose measles–mumps–rubella(MMR) achieved high coverage in Quzhou. The supplementary immunization activities (SIA) using measles mumps (MM) was conducted to control mumps outbreaks. The effectiveness of one and two doses of mumps-containing vaccine (MuCV) was assessed using surveillance data in this study. Mumps cases and immunization information were retrieved from the National Notifiable Disease Reporting System (NNDRS) and the Zhejiang Provincial Immunization Information System (ZJIIS), respectively. Mumps cases of children born from 2006 to 2010 were included. Vaccine effectiveness by dose was calculated using the screening method. A total of 956 mumps cases were identified, of whom 754 (78.9%) had received one dose of MuCV; 108 (11.3%) had received two doses; 94 (9.8%) were unvaccinated. The coverage of one-dose MuCV in the 2006–2010 birth cohorts ranged from 91.6% to 98.9%. Except the 2009 birth cohort in which the coverage of two doses of MuCV was 55.1%, the others were less than 10%. Vaccine effectiveness (VE) of one dose ranged from 47.4% to 86.0%, while VE of two doses ranged from 64.0% to 92.4%. The VE of one and two doses of MuCV waned over time, but the VE of two doses was consistently higher than that of one dose in the same period. The vaccine schedule with two-dose MMR should be implemented among children in Quzhou. The optimal age for the second dose needs to be further evaluated.

Association between Meteorological Factors and Mumps and Models for Prediction in Chongqing, China.

(1) Background: To explore whether meteorological factors have an impact on the prevalence of mumps, and to make a short–term prediction of the case number of mumps in Chongqing. (2) Methods: K–means clustering algorithm was used to divide the monthly mumps cases of each year into the high and low case number clusters, and Student t–test was applied for difference analysis. The cross–correlation function (CCF) was used to evaluate the correlation between the meteorological factors and mumps, and an ARIMAX model was constructed by additionally incorporating meteorological factors as exogenous variables in the ARIMA model, and a short–term prediction was conducted for mumps in Chongqing, evaluated by MAE, RMSE. (3) Results: All the meteorological factors were significantly different (p < 0.05), except for the relative humidity between the high and low case number clusters. The CCF and ARIMAX model showed that monthly precipitation, temperature, relative humidity and wind velocity were associated with mumps, and there were significant lag effects. The ARIMAX model could accurately predict mumps in the short term, and the prediction errors (MAE, RMSE) were lower than those of the ARIMA model. (4) Conclusions: Meteorological factors can affect the occurrence of mumps, and the ARIMAX model can effectively predict the incidence trend of mumps in Chongqing, which can provide an early warning for relevant departments.

Vaccine failure, seasonality and demographic changes associate with mumps outbreaks in Jiangsu Province, China: Age-structured mathematical modelling study

Measles, mumps and rubella (MMR) vaccine program was introduced in Jiangsu province of China in May 2008 and has been greatly contributed to decreasing of mumps cases. However, mumps has been resurging since May 2015. A number of studies have put forward that the resurgence of mumps is due to vaccine failure. In this paper, we investigated the other reasons for the resurging of mumps, such as the changes in seasonal transmission patterns and demographic structures, by using an age-structured mathematical model. We divided the history (January 2005 to May 2019) of mumps epidemics of Jiangsu province into three different stages: No vaccine stage (January 2005 to December 2008), effectively controlled stage (January 2009 to December 2014) and resurgence stage (January 2015 to May 2019). The features of mumps epidemics in three stages are compared under different demographic structures with same physical contact rate. The mumps transmission rate was increased in summer and dropped in November in stage III compared with that in stage I. The changes in demographic structures give a good explanation why the mumps outbreaked among children around 10 years old in stage I and around 5 years old in stage III. We have a conclusion that the vaccine failure, changes in seasonality and demographic structures were associated with the mumps outbreaks in recent years in Jiangsu province, China. We give the patterns of mumps dynamics considering age, vaccine, seasonality and demographic structures, which can help health program planners to implement more preventive interventions in mumps control during the period of higher risk of infection.