Seroprevalence Of Mumps Research Articles

A seroepidemiological study across age groups before and after the 2010-2011 mumps epidemic in Japan.

In Japan, large-scale mumps epidemics recur every 4-6 years because of low vaccination coverage. This study aimed to describe the seroprevalence of mumps in the Japanese population and identify the age groups most affected. The prevalence of anti-mumps antibodies was evaluated based on 1000 serum samples obtained from the Japanese National Serum Reference Bank. These samples consisted of 50 sera for each of 10 different age groups, collected during 2007-2008 (pre-epidemic period) and 2012-2013 (post-epidemic period). Seropositivity was lowest in the 6-11 months subgroup (3% and 0% in pre- and post-epidemic periods, respectively) and highest in the 10-14 years group (66% and 72% in pre- and post-epidemic periods, respectively). A comparison of anti-mumps antibody prevalence throughout the two periods considered revealed a large rise in seropositivity among the 2004-2008 birth cohort, using that of the 1-4 years group as representative in the pre-epidemic period (from 22% in pre- to 58% in post-epidemic periods;p = 0.0002). These results indicate that most people likely gain antibodies to the mumps virus during their childhood, especially during the first epidemic that they experience after their second year of life. Therefore, children should be vaccinated against mumps soon after their first birthday for effective prevention.

Mumps serological surveillance following 10 years of a one-dose mumps-containing-vaccine policy in Fujian Province, China

ABSTRACT Background Since 2008, Fujian province provided measles-rubella (MR) vaccine at 8 months followed by measles-mumps-rubella (MMR) vaccine at 18 months a one-dose mumps-containing-vaccine (MuCV) schedule. Several mumps outbreaks have occurred recently in Fujian. Serological surveillance can assess population immunity to mumps and identify risk factors for mumps. Methods We conducted a cross-sectional serosurvey of mumps IgG antibodies in the general population of Fujian Province in 2018 and compare results with a similar study conducted in 2009, when the routine schedule had no MuCV. We analyzed changes in mumps epidemiology after implementation of a one-dose MuCV vaccination strategy. Results Mumps seroprevalence was 78.6% (95% CI: 77.4–79.8), and the geometric mean concentration (GMC) of mumps antibodies was 245.8 IU/ml (95% CI:237.3–255.1). MuCV vaccination at 18 months resulted in increased seroprevalence and GMCs. Seroprevalence and GMCs varied by age, gender, and number of doses received. Except for children under 18 months, seroprevalence and GMCs were lowest among 10-15-year-olds. Each year after introduction of the one-dose MuCV vaccination policy, the highest incidence of mumps was among 4–6-year-olds and 9–15-year-olds, gradually shifting to older age groups. Conclusion A one-dose mumps-containing vaccine schedule does not provide sustained and stable mumps immunity in Fujian. To reduce the risk of mumps, we recommend supplementary vaccination of children without a history of receiving at least one MuCV dose or who are seronegative at 10–15 years of age.

The Concordance between Mumps and Rubella Sero-Positivity among the Israeli Population in 2015.

Mumps and rubella are vaccine-preventable viral diseases through the measles-mumps-rubella-varicella (MMRV) vaccine, administered at 12 months and again at 6 years. We assessed the sero-prevalence of mumps and rubella, identified factors associated with sero-negativity, and evaluated concordance between mumps and rubella sero-positivity. A national cross-sectional sero-survey was conducted on samples collected in 2015 by the Israel National Sera Bank. Samples were tested for mumps and rubella IgG antibodies using an enzyme-linked immunosorbent assay. Of 3131 samples tested for mumps IgG, 84.8% (95%CI: 83.5–86.0%) were sero-positive. Sero-negativity for mumps was significantly associated with age (high odds ratios observed in infants younger than 4 years and 20–29 years old subjects). Of 3169 samples tested for rubella IgG antibodies, 95.2% (95%CI: 94.4–95.9%) were sero-positive. Rubella sero-negativity was significantly associated with age (high odds ratios observed in children younger than 4 years old and adults older than 30 years), males, Jews, and others. Concordant sero-positivity for both mumps and rubella viruses was observed in 83.9% of the tested samples. The Israeli population was sufficiently protected against rubella but not against mumps. Since both components are administered in the MMRV vaccine simultaneously, the mumps component has a lower uptake than rubella and quicker waning.

Sero-prevalence of Mumps among Unvaccinated Children Attending Regional Referral Hospitals in Dar es Salaam, Tanzania

Aims: Mumps infection and its complication remain under recognized public health problem in Tanzania, as there are no national screening program and sero-epidemiological surveys. This makes it difficult to devise control interventions including administration of vaccinations. We therefore determined the Sero-prevalence of Mumps among Unvaccinated Children Attending Regional Referral Hospitals in Dar es salaam, Tanzania.
 Study Design: A hospital based cross-sectional study.
 Place and Duration of Study: Outpatient departments of three regional hospitals in Dar es Salaam Tanzania: Amana, Mwananyamala, and Temeke hospitals, from March to June 2021.
 Methodology: Three hundred and sixty children aged 1 - 16 years were included in the study. A structured questionnaire was used to collect participants' information. Serum samples were tested for mumps immunoglobulin G antibodies using an enzyme linked immune-sorbent assay. Proportions were used to describe children's social demographic and clinical characteristics, and binary logistic regression was used to estimate the odds of exposure to mumps virus. A p-value < 0.05 was considered statistically significant.
 Results: The mean age was 7.6 ± 4.1, half of them were females. More than three quarters (77%) of the children had Mumps Immunoglobulin-G. Mumps sero-prevalence among under-fives was 58.8%, among 5-8 years was 80%, 9-12 years was 86% and for 13-16 year was 88%. Compared to under-fives, children in the ages of 5-8, 9-12 and 13-16 had four times.
 (OR 4.19 95% CI 1.49-11.7), five times (OR 5.84 95% CI 1.89-18.12) and six times (OR 6.00 95% CI 1.63-21.43) higher odd of mumps exposure respectively. The number of siblings in the house, going to school, and previous history of parotid gland enlargement were not associated with mumps sero-positivity.
 Conclusion: The mumps virus is circulating in a high proportion among children in Dar es Salaam and the likelihood of exposure increases with age.

Seroprevalence of mumps among children and adolescents in Thailand, 2020

Thailand has implemented single-dose mumps-containing vaccines since 1997 and two doses since 2010. This study aimed to describe the seroprevalence of mumps among children who received one- or two-dose mumps vaccines. A cross-sectional study of 145 children (aged 3–9 years) and 422 adolescents (10–18 years) was conducted. Mumps IgG seropositivity was defined as ≥ 22 RU/mL by EUROIMMUN ELISA method. The mumps seroprevalence was higher in children (82.1%, 95% CI 74.8–87.9) compared to adolescents (41.7%, 95% CI 37.0–46.6) who had received at least one dose of the mumps vaccine. Among those receiving 2 doses of mumps vaccine at ≥ 5 years after their last mumps vaccination, only 51.3% had maintained IgG ≥ 22 RU/ml. There was a reverse correlation between mumps IgG titer and the time interval from the second dose of mumps vaccine (R = -0.44, p < 0.001). A booster dose of MMR vaccine in young adults may be needed.

Determination of ELISA reactive mumps IgG antibodies in MMR vaccine recipients in comparison with MMR vaccine naive children: A cross sectional study

Background/Aim: Mumps is by vaccine preventable infectious disease characterised by parotitis. In India mumps vaccines are not currently used under National Immunisation Programme (NIP). Waning of vaccine-induced immunity is considered to play a central role in the re-emergence of mumps. The comprehensive data on the seroepidemiology of measles, mumps, and rubella (MMR) as well as studies which compare the antibody titre among mumps vaccine naiveand mumps vaccinated children are lacking. The aim of this study was to estimate and compare mumps specific antibody titre in children with and without MMR vaccine. Methods: In 2019/2020, blood samples were collected from 100 healthy children attending immunisation clinic in Government Medical College Kota and associated J K Lon Maternal and Child care hospital Kota. The samples were investigated for MMR IgG antibodies using ELISA. Results: Out of total 100 children included in the study, 32.27 % vaccinated and 4.83 % non-vaccinated children were positive for mumps IgG antibody in the age group of 6 months to 6 years of age. Children aged 6 to 12 years, vaccinated and non-vaccinated, had 31.57 % and 26.57 % positivity, respectively. The seroprevalence of measles, mumps and rubella antibodies among 50 MMR vaccinated children were 94 %, 64 %, and 96 %, respectively. A high measles and rubella seroprevalences were observed among all children age groups, suggesting an effective control program, while the mumps seroprevalence decreased significantly with age. Conclusion: The maximum vaccine effectiveness against mumps for 2 doses of MMR vaccine is ≈ 96 %. The herd immunity threshold to block mumps virus transmission is ≥ 86 %. In this study only 64 % of the vaccinated children were found to have IgG mumps antibodies. In view of morbidity following mumps infection there is a need to incorporate mumps vaccine along with measles and rubella vaccine in the NIP instead of Mr.

1076. Gaps in Measles and Mumps Seroprevalence Among Cancer Patients

BackgroundImmunosuppressed cancer patients are at risk for morbidity and mortality from vaccine preventable diseases. Recent outbreaks and declining vaccination rates put cancer patients at increased risk for measles and mumps exposures. To assess the current status within our center, we measured measles and mumps seroprevalence among cancer patients.MethodsResidual clinical plasma samples from patients seen at Seattle Cancer Care Alliance were collected between 8/11/2019 and 8/15/2019 and tested for measles and mumps IgG using ELISA (Genway Biotech); patients receiving intravenous immunoglobulin ≤16 weeks prior to collection date were excluded. Seroprevalence was calculated based on positive results; equivocal results were not considered protective. Demographic and clinical data were abstracted from medical records. Overall and subgroup seroprevalence were estimated with Wilson 95% confidence intervals (CI); Poisson regression with robust standard errors was used to compare subgroups and estimate prevalence ratios (PR).ResultsOf 1000 unique patients, 987 were eligible, with a median age of 61 years (range 2-97). More than half had a solid tumor (574 [58%]) while 376 (38%) had a hematologic malignancy (HM); 155 (16%) were hematopoietic cell transplant (HCT) recipients. The percentage of seropositive patients was 75% (95% confidence interval [CI]: 72%, 78%) for measles and 62% (95% CI: 59%, 65%) for mumps. Seropositivity was highest among older age groups, particularly those older than 63, who most likely have naturally acquired immunity (Figure 1-2). In multivariable analysis, patients aged 30-59 years were significantly less likely to be seropositive compared to patients ≥80 years of age. Patients with HM and those undergoing HCT were also less likely to be seropositive (Figure 3).Figure 1. Distribution of age at sample collection and measles antibody test results Figure 2. Measles and mumps seroprevalence by age Figure 3. Multivariable model estimates for measles and mumps seroprevalence ConclusionOne-quarter of cancer patients tested did not have evidence of seroprotection for measles and mumps. Seronegative and equivocal responses were observed primarily among younger patients and those with hematologic malignancies. Deficits in protective antibody seen in this study are common among cancer patients and underscore the need for population/community-based efforts to increase herd immunity and protect vulnerable populations.Disclosures Helen Y. Chu, MD MPH, Cepheid (Grant/Research Support)Ellume (Grant/Research Support)Glaxo Smith Kline (Consultant)Merck (Consultant)Sanofi-Pasteur (Grant/Research Support) Steven A. Pergam, MD, MPH, Chimerix, Inc (Scientific Research Study Investigator)Global Life Technologies, Inc. (Research Grant or Support)Merck & Co. (Scientific Research Study Investigator)Sanofi-Aventis (Other Financial or Material Support, Participate in clinical trial sponsored by NIAID (U01-AI132004); vaccines for this trial are provided by Sanofi-Aventis)

Seroprevalence of Mumps in Healthcare Workers in South Korea

Background: Mumps, a contagious disease, is transmissible by respiratory droplet particles and is preventable by vaccination. In South Korea, mandatory vaccination against mumps has markedly reduced its incidence. However, both the incidence and the number of reported cases of mumps have persistently increased in South Korea since 2007. Despite high vaccination rates, mumps outbreaks continue to occur, and many studies have been conducted on mumps seroprevalence in children and adolescents. In comparison, few reports have been published regarding mumps seroprevalence in healthcare workers (HCWs) in South Korea. Objective: We investigated the seroprevalence of HCWs in South Korea. Methods: This study was conducted at Asan Medical Center, a 2,705-bed tertiary-care hospital in Seoul, South Korea, with 8,329 HCWs. In 2018, we performed mumps antibody testing for HCWs. We administered MMR vaccination to all HCWs whose antibody test yielded equivocal or negative results. However, we did not repeat mumps antibody testing after MMR vaccination. Results: In total, 6,055 HCWs (73%) underwent mumps antibody testing. The overall mumps seropositivity rate was 87% (95% CI, 86%–87%). Seropositivity rates of all birth cohorts ranged from 72% to 92%. Mumps seropositivity rates were 88% in HCWs born before 1970, 87% in those born between 1970 and 1989, and 88% in those born between 1990 and 1995 (P = .59). Mumps seropositivity rates for both women and men HCWs were 87% (3,770 of 4,311 women and 1,517 of 1,744 men); the difference was not statistically significant (P = .62). The overall mumps seropositivity rate was 87%, which was above the herd immunity threshold of 75%–86%. Conclusions: Our results revealed that the overall mumps seropositivity rate in South Korean HCWs was above the herd immunity threshold. On the basis of this finding, we recommend that MMR vaccination after serologic testing may be a more reasonable approach than universal MMR vaccination alone in Korea.Funding: NoneDisclosures: None

Seroprevalence of mumps in healthcare workers in South Korea

Mumps is contagious disease and maintaining immunity to mumps in healthcare worker (HCW) is important for preventing transmission in the hospital. We evaluated the seroprevalence of mumps in HCWs in a tertiary care hospital in Republic of Korea. A total of 6,055 HCWs born between 1950 and 1995 underwent antibody testing. The overall seropositivity rate of mumps was 87% (95% confidence interval, 86%–87%). Our data indicates that, in Korean HCWs, testing for mumps antibody followed by mumps vaccination is more appropriate than routine mumps vaccination without testing for mumps antibody.

Investigation of a Mumps Outbreak in a Dental Clinic at a University Hospital

BackgroundThe Korean Society of Infectious Diseases recommends non-mandatory vaccination of newly employed healthcare workers (HCWs) with 2 measles–mumps–rubella (MMR) vaccine doses. Here, we aimed to investigate the seroprevalence of mumps among HCWs exposed to index patients with mumps and the efficacy of MMR vaccination as postexposure prophylaxis (PEP) when a mumps outbreak was encountered among HCWs in a tertiary university hospital in Korea.Materials and MethodsFour HCWs were diagnosed with mumps over a 4-day period in January 2016. Three were working at a dental clinic and one visited the clinic on the day of symptoms onset of the first patient. We investigated all HCWs who either worked in that dental clinic, visited the clinic, or being within 1.5 meter of the patients with mumps without wearing surgical masks. Seventy HCWs were exposed to 4 HCWs with mumps. We interviewed all the exposed HCWs to investigate mumps infection and MMR vaccination history; they were all tested for mumps IgG.ResultsOf the 70 exposed HCWs, 56 (80%) were females; the median age was 34 years (range 21–59 years) and 3 had a history of mumps infection. The vaccination status verification of mumps among the HCWs was unavailable. As for serologic testing, 54 (77.1%) were seropositive. Seropositivity rate for the mumps virus in males was significantly lower than that in females (50.0% vs. 83.9% respectively, P = 0.007). A lower seroprevalence of mumps was observed among HCWs aged ≥40 years than those aged <40 years; however, this difference was not significant (65.2% vs. 83.0%, P = 0.096). During the initial intervention, all exposed HCWs were vaccinated because the turnaround time for serologic testing was expected to be >2 days. Thirty-four (62.9%) of 54 seropositive HCWs and 16 seronegative HCWs were administered MMR vaccines as PEP and following this, no additional cases of mumps were encountered during the maximum incubation period.ConclusionOf the exposed HCWs, 77.1% were mumps-seropositive. Seropositive rates differed according to factors such as age and sex. Eligible HCWs received a MMR vaccine as PEP and no additional mumps cases occurred during the incubation period. It was useful in our infection control activities during the mumps outbreak.

Manisa ilinde kabakulak seroprevalansı ve bazı sosyal belirleyicilerle ilişkisi, 2014

Aims: The aim of this study was to determine the seroprevalence of mumps and its association with some social determinants of health in the Manisa Province. Method: A random sample of individuals, aged two years and over, from the Manisa Province was included in this cross-sectional study (n=1740). Individuals were interviewed and blood samples were taken in family health centres. Specific antibodies were analysed using the anti-mumps virus ELISA IgG test and values of ≥22 IU/mL were considered as positive. Results: Overall mumps seropositivity was found to be 80.3%. Furthermore, seropositivity was 72.5% for ages 2-19 and 83.1% for ages over 20 (p&amp;lt;0.01). The Odds Ratio of mumps seropositivity was 1.42 (0.94-2.08) for people who had an annual equivalent income per capita of more than 5692 TL; and OR = 1.23 (0.54-2.82) for people who were living in homes which had fewer than one person per room. Conclusions: In all age groups, there is between 10-20% of the population sensitive to the risk of a mumps epidemic. There is no statistically significant association between mumps seropositivity and social determinants. For a successful mumps control program, high vaccine coverage should be aimed and maintained.

Seroprevalence of mumps in an epidemic period in Medellín, Colombia

ObjectiveWe related seroprevalence and outbreaks data in order to identify factors that could explain the occurrence of outbreaks despite high vaccination coverage in Medellín Colombia. MethodsSamples from a population seroprevalence data obtained in 2009 in a random survey were analyzed. IgG levels were determined for mumps using 2 commercial tests of 2119 individuals aged 6–64 years. A comparative analysis was undertaken using age–specific mumps seroprevalence data and information of 98 epidemiological investigations of mumps outbreaks reported in 2009. ResultsOverall, seroprevalence was 91.6% (95% CI=89.3–93.5%). The age-specific seronegativity was 20.3% and 20.6% in age groups 11–15 years and 16–20 years respectively. Individuals aged 6–20 years were the most affected during outbreaks. In individuals born in 2003, a year after the change in the booster schedule from 10 to 5 years, the proportion of unvaccinated individuals (14%) and those who received only one dose of MMR (45%) increased substantially. On average, 23.5 days elapsed between the onset of symptoms in secondary cases and the outbreak investigation. ConclusionPotential contributing factors for the occurrence of outbreaks of mumps were the relatively high prevalence of seronegativity among individuals aged 11–20 years, delays in investigation and control of outbreaks, and incomplete vaccination schedules.

Seroprevalence of measles, mumps and rubella among young adults, after 20 years of universal 2-dose MMR vaccination in Israel

Evidence-based vaccination policy is important for the global and local efforts of achieving control over measles. In 2007, the first Israeli birth cohort to be twice vaccinated during childhood with Measles-Mumps-Rubella vaccine reached adulthood. In parallel, Israel experienced its largest measles outbreak since 1994. We aimed to assess the seroprevalence of measles IgG antibodies and concordance with rubella and mumps seroprevalence among young Israeli adults born 1988–9 in comparison to previous birth cohorts, in order to inform evidence based prevention policy. We conducted a seroprevalence study of IgG antibodies among 439 Israeli adults born in 1988–9, based on a representative sample of sera collected at age 18–19 upon recruitment to mandatory military service in 2007. In total, 85.7% were seropositive for measles as compared with 95.6% in the 1996 recruitment (P < 0.001). The absolute decline was significant both for males (8.8%, P = 0.001) and females (12.1%, P < 0.001). There were no significant differences in seropositivity by gender, years of education, country of birth or smoking status. Rubella seropositivity among measles seropositives was 90.4%, significantly (P < 0.001) higher than 72.1% among measles seronegatives. Mumps seropositivity among measles seropositives was 87.0%, significantly (P < 0.001) higher than 62.3% among measles seronegatives. Results were similar for Israeli-born only. Our findings indicate that measles seroprevalence decreased after the last change in vaccination policy and reach sub-optimal level. Until global eradication is reached, a proactive vaccination program to supplement routine childhood vaccination program should be considered in Israel and in other countries.

Seroprevalence of measles, mumps, rubella and varicella antibodies in the United States population, 2009-2010.

Background. In the United States, measles, mumps, rubella, and varicella immunity is now primarily achieved through vaccination. Monitoring population immunity is necessary.Methods. We evaluated seroprevalence of antibodies to measles, mumps, rubella, and varicella using the National Health and Nutrition Examination Survey during 2009–2010.Results. Measles, mumps, rubella, and varicella seroprevalence was 92.0% (95% confidence interval [CI], 90.9%−93.0%), 87.6% (CI, 85.8%−89.2%), 95.3% (CI, 94.3%−96.2%), and 97.8% (CI, 97.1%−98.3%), respectively. United States (US)-born persons had lower mumps seroprevalence and higher varicella seroprevalence than non-US born persons.Conclusions. Seroprevalence was high (88%–98%) for all 4 viruses in the US population during 2009−2010.

Assessing Mumps Outbreak Risk in Highly Vaccinated Populations Using Spatial Seroprevalence Data

Mumps is a potentially severe viral infection. The incidence of mumps has declined dramatically in high-income countries since the introduction of mumps antigen-containing vaccines. However, recent large outbreaks of mumps in highly vaccinated populations suggest waning of vaccine-induced immunity and primary vaccine failure. In this paper we present a simple method for identifying geographic regions with high outbreak potential, demonstrated using 2006 mumps seroprevalence data from Belgium and Belgian vaccination coverage data. Predictions of the outbreak potential in terms of the effective reproduction number in future years signal an increased risk of new mumps outbreaks. Literature reviews on serological information for both primary vaccine failure and waning immunity provide essential information for our predictions. Tailor-made additional vaccination campaigns would be valuable for decreasing local pockets of susceptibility, thereby reducing the risk of future large-scale mumps outbreaks.

Estimates of Mumps Seroprevalence May Be Influenced by Antibody Specificity and Serologic Method

Neutralizing antibodies are assumed to be essential for protection against mumps virus infection, but their measurement is labor- and time-intensive. For this reason, enzyme-linked immunosorbent assays (ELISAs) are typically used to measure mumps-specific IgG levels. However, since there is poor correlation between mumps neutralization titers and ELISAs that measure the presence of mumps-specific IgG levels, ELISAs that better correlate with neutralization are needed. To address this issue, we measured mumps antibody levels by plaque reduction neutralization, by a commercial ELISA (whole-virus antigen), and by ELISAs specific for the mumps nucleoprotein and hemagglutinin. The results indicate that differences in the antibody response to the individual mumps proteins could partially explain the lack of correlation among various serologic tests. Furthermore, the data indicate that some seropositive individuals have low levels of neutralizing antibody. If neutralizing antibody is important for protection, this suggests that previous estimates of immunity based on whole-virus ELISAs may be overstated.

Seroprevalence of Mumps in The Netherlands: Dynamics over a Decade with High Vaccination Coverage and Recent Outbreaks

Here we present mumps virus specific antibody levels in a large cross-sectional population-based serosurveillance study performed in the Netherlands in 2006/2007 (n = 7900). Results were compared with a similar study (1995/1996) and discussed in the light of recent outbreaks. Mumps antibodies were tested using a fluorescent bead-based multiplex immunoassay. Overall seroprevalence was 90.9% with higher levels in the naturally infected cohorts compared with vaccinated cohorts. Mumps virus vaccinations at 14 months and 9 years resulted in an increased seroprevalence and antibody concentration. The second vaccination seemed to be important in acquiring stable mumps antibody levels in the long term. In conclusion, the Dutch population is well protected against mumps virus infection. However, we identified specific age- and population groups at increased risk of mumps infection. Indeed, in 2007/2008 an outbreak has occurred in the low vaccination coverage groups emphasizing the predictive value of serosurveillance studies.

168. Mumps Seroprevalence Among Detained Youth in Maryland, 2011: Local, Regional and National Policy Implications

168. Mumps Seroprevalence Among Detained Youth in Maryland, 2011: Local, Regional and National Policy Implications

Seroprevalence of Measles- and Mumps-Specific Immunoglobulin G among Japanese Healthcare Students Increased during 2007&amp;ndash;2012

We evaluated the seroprevalence of vaccine-preventable infectious diseases among Japanese healthcare students to create immunization guidelines. Between 2007 and 2012, a total of 1746 Japanese medical, nursing, and paramedical students were serologically screened for measles, mumps, rubella, varicella, and hepatitis B virus (HBV) antibodies at the time of admission. In 2007, the seroprevalence of measles and mumps was 52.7% and 65.6%, respectively. The seroprevalence of measles dramatically increased to 96.6% in 2009 and was then sustained at >90%. The seroprevalence of mumps gradually increased to >80.0% between 2010 and 2012. The seroprevalence of rubella remained at >90% except in 2008 (85.6%), and the seroprevalence of varicella was sustained at >92% throughout 2007-2012. The seroprevalence of HBV antibody remained at <7% during 2007-2012. Although the seroprevalence of vaccine-preventable infectious diseases among Japanese healthcare students increased during the 2007-2012 study period, a substantial number of students were susceptible to vaccine-preventable infectious diseases. Therefore, we propose targeted immunization of Japanese healthcare students using serological screening prior to clinical training.

Seroepidemiology of mumps in Europe (1996–2008): why do outbreaks occur in highly vaccinated populations?

Mumps outbreaks have recently been recorded in a number of highly vaccinated populations. We related seroprevalence, epidemiological and vaccination data from 18 European countries participating in The European Sero-Epidemiology Network (ESEN) to their risk of mumps outbreaks in order to inform vaccination strategies. Samples from national population serum banks were collected, tested for mumps IgG antibodies and standardized for international comparisons. A comparative analysis between countries was undertaken using age-specific mumps seroprevalence data and information on reported mumps incidence, vaccine strains, vaccination programmes and vaccine coverage 5-12 years after sera collection. Mean geometric mumps antibody titres were lower in mumps outbreak countries [odds ratio (OR) 0·09, 95% confidence interval (CI) 0·01-0·71)]. MMR1 vaccine coverage ⩾95% remained protective in a multivariable model (P < 0·001), as did an interval of 4-8 years between doses (OR 0·08, 95% CI 0·01-0·85). Preventing outbreaks and controlling mumps probably requires several elements, including high-coverage vaccination programmes with MMR vaccine with 4-8 years between doses.