Spread of measles virus D4-Hamburg, Europe, 2008-2011

Measles Epidemiology and Viral Nucleoprotein Gene Evolution in Shandong Province, China

Measles, caused by measles virus (MeV), has not been eradicated in many regions and countries, threatening human health. Thus, it is beneficial for measles elimination to understand measles epidemiology and molecular evolution of key viral genes, such as nucleoprotein (N) gene. Based on public data, measles epidemiological information and MeV N gene sequences reported in Shandong Province, China were comprehensively collected and systematically analyzed. The results showed a positive correlation between population density and measles incidence (r = + 0.31), while negative correlations were found between measles incidence and healthcare condition (r = - 0.21) as well as average routine vaccination rate (r = - 0.11). Additionally, the predominant lineage of MeV in Shandong was formed by genotype H1 strains, and the time of the most recent common ancestor of the N gene of MeV genotype H1 in Shandong traced back to 1987 (95% highest posterior density, 1984-1990) with relatively rapid evolution (mean rate, 1.267×10^-3 substitutions/site/year). The genetic diversity of MeV N gene increased with the substantial emergence of major divergent clades of genotype H1 before 2005 and then remained relatively stable. In summary, these findings provided a significant insight into the measles elimination. This article is protected by copyright. All rights reserved.

Evolving measles status and immunization policy development in six European countries

Developing and implementing new immunization policies in response to shifting epidemiology is a critical public health component. We adopted a mixed-methods approach (via narrative literature review [101 articles] and 9 semi-structured interviews) to evaluate policy development in response to shifting measles epidemiology in six European countries (Italy, Belgium, Germany, Romania, UK, and Ukraine); where policies and strategies have evolved in response to country-specific disease and vaccination patterns. Periodic outbreaks have occurred in all countries against a background of declining measles-containing-vaccine (MCV) uptake and increasing public vaccine hesitancy (with substantial regional or social differences in measles burden and vaccine uptake). Health-care worker (HCW) vaccine skepticism is also seen. While many outbreaks arise or involve specific susceptible populations (e.g., minority/migrant communities), the broader pattern is spread to the wider (and generally older) population; often among incompletely/non-vaccinated individuals as a legacy of previous low uptake. Immunization policy and strategic responses are influenced by political and social factors, where public mistrust contributes to vaccine hesitancy. A strong centralized immunization framework (allied with effective regional implementation and coherent political commitment) can effectively increase uptake. Mandatory vaccination has increased childhood MCV uptake in Italy, and similar benefits could be anticipated for other countries considering vaccine mandates. Although possible elsewhere, socio-political considerations render mandating impractical in other countries, where targeted immunization activities to bolster routine uptake are more important. Addressing HCW skepticism, knowledge gaps, improving access and increasing public/community engagement and education to address vaccine hesitancy/mistrust (especially in communities with specific unmet needs) is critical.

Migration and outbreaks of vaccine-preventable disease in Europe: a systematic review

Migrant populations are one of several underimmunised groups in the EU or European Economic Area (EU/EEA), yet little is known about their involvement in outbreaks of vaccine-preventable diseases. This information is vital to develop targeted strategies to improve the health of diverse migrant communities. We did a systematic review (PROSPERO CRD42019157473; Jan 1, 2000, to May 22, 2020) adhering to PRISMA guidelines, to identify studies on vaccine-preventable disease outbreaks (measles, mumps, rubella, diphtheria, pertussis, polio, hepatitis A, varicella, Neisseria meningitidis, and Haemophilus influenzae) involving migrants residing in the EU/EEA and Switzerland. We identified 45 studies, reporting on 47 distinct vaccine-preventable disease outbreaks across 13 countries. Most reported outbreaks involving migrants were of measles (n=24; 6496 cases), followed by varicella (n=11; 505 cases), hepatitis A (n=7; 1356 cases), rubella (n=3; 487 cases), and mumps (n=2; 293 cases). 19 (40%) outbreaks, predominantly varicella and measles, were reported in temporary refugee camps or shelters. Of 11 varicella outbreaks, nine (82%) were associated with adult migrants. Half of measles outbreaks (n=11) were associated with migrants from eastern European countries. In conclusion, migrants are involved in vaccine-preventable disease outbreaks in Europe, with adult and child refugees residing in shelters or temporary camps at particular risk, alongside specific nationality groups. Vulnerability varies by disease, setting, and demographics, highlighting the importance of tailoring catch-up vaccination interventions to specific groups in order to meet regional and global vaccination targets as recommended by the new Immunisation Agenda 2030 framework for action. A better understanding of vaccine access and intent in migrant groups and a greater focus on co-designing interventions is urgently needed, with direct implications for COVID-19 vaccine delivery.

Epidemiological Investigation and Virus Tracing of a Measles Outbreak in Zhoushan Islands, China, 2019

Background: Measles transmissions due to case importations challenge public health systems globally and herd immunities in all countries. In 2019, an imported measles case and its subsequently outbreak was found in the Zhoushan Islands. Here, the process of epidemiological investigation and virus tracing were summarized to provide references for the prevention and control of measles in the future. Materials and methods: The data on the demographic, epidemiological, and clinical manifestation of measles cases in this outbreak were collected. The 450 bp fragments of the measles virus (MeV) N gene were amplified and sequenced. The genome of the first imported case was further isolated. Then, the maximum-likelihood and time-scaled phylogenetic analysis was conducted. Results: A total of 28 measles cases were confirmed. Their onsets were between March 13 and May 18, 2019. The first patient was from the Ukraine. He was confirmed at the Fever Clinic in Zhoushan hospital on March 15, 2019 and at the same time, another patient had visited the hospital due to another illness and 10 days later, this second case had onset (March 25, 2019). The epidemic curve shows sustained community transmission. The majority of the following cases (19/26) were clustered on the Donggang street which was close to where the second case worked. The 22 measles virus strains successfully isolated from this outbreak all belonged to the D8.2a sub-cluster and clustered with the KY120864/MVs/GirSomnath.IND/42.16/[D8] which was the predominant genotype in the Ukraine during 2018-2019. The analysis of the complete D8 genotype genome pointed to the fact that this prevailing strain originated from India in 2015 and its substitution rate was estimated as 6.91 × 10^-4 (5.64-7.98 × 10^-4) nucleotide substitutions/site/year. Conclusion: This outbreak was caused by an imported case from the Ukraine. There was a possible nosocomial infection between the first case and the second case. Then, the second case played an important role in the spread of virus due to her occupation. The molecular phylogenetic analysis could help to track the origin of the virus. Increasing and maintaining the high level of vaccination coverage (≥95%) and an efficient response to imported cases are essential to prevent and control the recurrence and outbreak of measles virus.

A genetic barcode of SARS-CoV-2 for monitoring global distribution of different clades during the COVID-19 pandemic

OBJECTIVE

The SARS-CoV-2 pathogen has established endemicity in humans. This necessitates the development of rapid genetic surveillance methodologies to serve as an adjunct with existing comprehensive, albeit though slower, genome sequencing-driven approaches.

METHODS

A total of 21,789 complete genomes were downloaded from GISAID on May 28, 2020 for analyses. We have defined the major clades and subclades of circulating SARS-CoV-2 genomes. A rapid sequencing-based genotyping protocol was developed and tested on SARS-CoV-2-positive RNA samples by next-generation sequencing.

RESULTS

We describe 11 major mutations which defined five major clades (G614, S84, V251, I378 and D392) of globally circulating viral populations. The clades can specifically identify using an 11-nucleotide genetic barcode. An analysis of amino acid variation in SARS-CoV-2 proteins provided evidence of substitution events in the viral proteins involved in both host entry and genome replication.

CONCLUSION

Globally circulating SARS-CoV-2 genomes could be classified into 5 major clades based on mutational profiles defined by an 11-nucleotide barcode. We have successfully developed a multiplexed sequencing-based, rapid genotyping protocol for high-throughput classification of major clade types of SARS-CoV-2 in clinical samples. This barcoding strategy will be required to monitor decreases in genetic diversity as treatment and vaccine approaches become widely available.

Characterisation of measles after the introduction of the combined measles-mumps-rubella (MMR) vaccine in 2004 with focus on the laboratory data, 2016 to 2019 outbreak, Romania

Background

Since January 2016, a resurgence of measles in Romania has led to the third measles epidemic in the past 12 years; 64 deaths have been confirmed so far–the highest number of measles-related deaths since the measles-mumps-rubella (MMR) vaccine was introduced in 2004.

Aim

To provide an overview on the characterisation on measles in Romania after the introduction of the MMR vaccine with focus on the current outbreak, laboratory and molecular analysis.

Methods

We performed an analysis of measles incidence and mortality after the introduction of MMR vaccination and a retrospective study using serological and molecular data in three consecutive outbreaks with focus on the current outbreak.

Results

In the current outbreak, 17,533 measles cases were notified to the national surveillance system, 93% were unvaccinated. Measles virus was isolated from 429 samples and 283 were genotyped. Genotype B3 was predominant (n = 269) and sporadic measles cases associated with D8 genotype (n = 9) were also observed; genotype D4 and D8 were identified in the previous two measles outbreaks. The detection of several distinct measles virus B3 genotypes suggests multiple virus importations to Romania.

Conclusion

The current outbreak is a consequence of insufficient vaccine coverage. Control measures were implemented to improve uptake of MMR vaccine, including administering the first MMR dose at a younger age (9–11 months) and offering catch-up vaccination to children that have not followed the recommended dosing schedule. More measures are needed to improve the surveillance performance and to achieve high routine MMR vaccination coverage.

Measles Virus Imported by International Traveler in Jiangsu Province of China, in 2018 and 2019

Measles remains a public health concern in many regions, and the imported measles cases continue to challenge the measles elimination program for most of the countries where measles was verified to be eliminated or approaching elimination. The imported measles cases have been reported since October, 2017, in Jiangsu province, China. In this study, we reported the first imported B3 genotype measles virus from Egypt and the second imported D8 genotype measles virus from Philippines through international traveling. No secondary measles cases were found after these imported cases. Our findings highlighted the importance of measles vaccination targeting international travelers in China.

Measles virus genotype D4 strains with non-standard length M-F non-coding region circulated during the major outbreaks of 2011-2012 in Spain

In recent decades, vaccination has substantially reduced the number of measles cases to levels close to the elimination stage. However, major measles outbreaks occurred in Europe during 2010-2012, after the introduction of the D4-Enfield lineage. We have performed a molecular characterization of 75 measles virus genotype D4 strains from patients infected in Spain between 2004 and 2012 by sequencing the N-450 region and the M-F non-coding region (M-F NCR) in order to identify genetic features of these viruses. The analysis of the N-450 region confirmed that all samples obtained since 2008 belonged to variants or sets of identical sequences of the D4-Enfield lineage, including a new one named MVs/Madrid.ESP/46.10/. Analysis of the M-F NCR showed insertions and deletions associated with previously described, uncommon non-standard genome length measles viruses. This genetic feature was identified in the D4-Enfield lineage viruses, but not in the other D4 viruses that were circulating in Spain before 2008, suggesting that these non-standard length M-F NCR sequences are characteristic of the D4-Enfield lineage. The results of the phylogenetic analysis of Spanish M-F NCRs suggest higher resolution in discriminating strains than did the N-450 analysis. In addition, the results of the analysis of the M-F NCR on the MVs/Madrid.ESP/46.10/ sub-lineage seem to support the potential utility of this region as a tool for epidemiological surveillance complementary to the N-450 region, as previously suggested. Further investigation on this question, as well as the surveillance of new potentially emerging strains with non-standard length M-F NCR are strongly recommended as part of future strategies for measles elimination.

Large measles outbreak introduced by asylum seekers and spread among the insufficiently vaccinated resident population, Berlin, October 2014 to August 2015

The largest measles outbreak in Berlin since 2001 occurred from October 2014 to August 2015. Overall, 1,344 cases were ascertained, 86% (with available information) unvaccinated, including 146 (12%) asylum seekers. Median age was 17 years (interquartile range: 4–29 years), 26% were hospitalised and a 1-year-old child died. Measles virus genotyping uniformly revealed the variant ‘D8-Rostov-Don’ and descendants. The virus was likely introduced by and initially spread among asylum seekers before affecting Berlin’s resident population. Among Berlin residents, the highest incidence was in children aged < 2 years, yet most cases (52%) were adults. Post-exposure vaccinations in homes for asylum seekers, not always conducted, occurred later (median: 7.5 days) than the recommended 72 hours after onset of the first case and reached only half of potential contacts. Asylum seekers should not only have non-discriminatory, equitable access to vaccination, they also need to be offered measles vaccination in a timely fashion, i.e. immediately upon arrival in the receiving country. Supplementary immunisation activities targeting the resident population, particularly adults, are urgently needed in Berlin.

Molecular surveillance of measles and rubella in the WHO European Region: new challenges in the elimination phase

BACKGROUND

The WHO European Region (EUR) has adopted the goal of eliminating measles and rubella but individual countries perform differently in achieving this goal. Measles virus spread across the EUR by mobile groups has recently led to large outbreaks in the insufficiently vaccinated resident population. As an instrument for monitoring the elimination process and verifying the interruption of endemic virus transmission, molecular surveillance has to provide valid and representative data. Irrespective of the country's specific situation, it is required to ensure the functionality of the laboratory surveillance that is supported by the WHO Global Measles and Rubella Laboratory Network.

AIMS

To investigate whether the molecular surveillance in the EUR is adequate for the challenges in the elimination phase, we addressed the quality assurance of molecular data, the continuity and intensity of molecular monitoring, and the analysis of transmission chains.

SOURCES

Published articles, the molecular External Quality Assessment Programme of the WHO, the Centralized Information System for Infectious Diseases of the WHO EUR and the WHO Measles and Rubella Nucleotide Surveillance databases served as information sources.

CONTENT

Molecular proficiency testing conducted by the WHO in 2016 has shown that the expertise for measles and rubella virus genotyping exists in all parts of the EUR. The analysis of surveillance data reported nationally to the WHO in 2013-2016 has revealed some countries with outbreaks but not sufficiently representative molecular data. Long-lasting supranational MV transmission chains were identified.

IMPLICATIONS

A more systematic molecular monitoring and recording of the transmission pattern for the whole EUR could help to create a meaningful picture of the elimination process.

The World Health Organization Measles Programmatic Risk Assessment Tool-Romania, 2015

Despite global improvement in annual measles incidence and mortality since 2000, progress toward elimination goals has slowed. The World Health Organization (WHO) European Region (EUR) established a regional goal for measles and rubella elimination by 2015. Romania is one of 13 EUR countries in which measles remains endemic. To identify barriers to meeting programmatic targets and to aid in prioritizing efforts to strengthen measles elimination strategy implementation, the WHO and U.S. Centers for Disease Control and Prevention developed a measles programmatic risk assessment tool that uses routinely collected data to estimate district-level risk scores. The WHO measles programmatic risk assessment tool was used to identify high-risk areas in order to guide measles elimination program activities in Romania. Of the 42 districts in Romania, 27 (64%) were categorized as very high or high risk. Many of the very-high-risk districts were clustered in the western part of the country or were clustered around the capital Bucharest in the southeastern part of the country. The overall risk scores in the very-high-risk districts were driven primarily by poor surveillance quality and suboptimal population immunity. The measles risk assessment conducted in Romania was the first assessment to be completed in a European country. Annual assessments using the programmatic risk tool could provide valuable information for immunization program and surveillance staff at the national level and in each district to guide activities to enhance measles elimination efforts, such as strengthening routine immunization services, improving immunization campaign planning, and intensifying surveillance.

Subacute Sclerosing Panencephalitis: The Foothold in Undervaccination

Subacute sclerosing panencephalitis (SSPE) is a fatal complication of measles infection. We present a case of a fully vaccinated 3-year-old boy who was diagnosed with and treated for autoimmune encephalitis before arriving at a diagnosis of SSPE. We discuss the challenges of diagnosing SSPE in developed countries.

Epidemiology and economic burden of measles, mumps, pertussis, and varicella in Germany: a systematic review

OBJECTIVES

Despite the availability of vaccines and the existence of public vaccination recommendations, outbreaks of vaccine-preventable childhood diseases still cause public health debate. The objective of this systematic review was to provide an overview of the current epidemiology and economic burden of measles, mumps, pertussis, and varicella in Germany.

METHODS

We systematically reviewed studies published since 2000. The literature search was conducted using PubMed and EMBASE. Also, we used German notification data to give an up-to-date overview of the epidemiology of the four diseases under consideration.

RESULTS

Thirty-six studies were included in our review. Results suggest that there is still considerable morbidity due to childhood diseases in Germany. Studies providing cost estimates are scarce. Comparative analyses of different data sources (notification data vs. claims data) revealed a potential underestimation of incidence estimates when using notification data. Furthermore, several studies showed regional differences in incidence of some of the diseases under consideration.

CONCLUSIONS

Our findings underline the need for improved vaccination and communication strategies targeting all susceptible age and risk groups on a national and local level.

The measles outbreak in Bulgaria, 2009-2011: An epidemiological assessment and lessons learnt

Measles re-emerged in a nationwide outbreak in Bulgaria from 2009 to 2011 despite reported high vaccination coverage at national level. This followed an eight-year period since the last indigenous cases of measles were detected. The Bulgarian National Centre of Infectious and Parasitic Diseases collated measles surveillance data for 2009-2011. We analysed data for age group, sex, ethnicity, diagnosis confirmation, vaccination, hospitalisation, disease complications, and death and describe the outbreak control measures taken. The outbreak started in April 2009 following an importation of measles virus and affected 24,364 persons, predominantly Roma. Most cases (73%) were among children < 15 years old. Vaccination status was available for 52% (n = 12,630) of cases. Of children 1-14 years old, 22% (n = 1,769) were unvaccinated and 70% (n = 5,518) had received one dose of a measles-containing vaccine. Twenty-four measles-related deaths were reported. The Roma ethnic group was particularly susceptible to measles. The magnitude of the outbreak resulted primarily from the accumulation of susceptible children over time. This outbreak serves as a reminder that both high vaccination coverage and closing of immunity gaps across all sections of the population are crucial to reach the goal of measles elimination.

Eradication of measles: remaining challenges

Measles virus (MeV) is an aerosol-borne and one of the most contagious pathogenic viruses known. Almost every MeV infection becomes clinically manifest and can lead to serious and even fatal complications, especially under conditions of malnutrition in developing countries, where still 115,000 to 160,000 patients die from measles every year. There is no specific antiviral treatment. In addition, MeV infections cause long-lasting memory B and T cell impairment, predisposing people susceptible to opportunistic infections for years. A rare, but fatal long-term consequence of measles is subacute sclerosing panencephalitis. Fifteen years ago (2001), WHO has launched a programme to eliminate measles by a worldwide vaccination strategy. This is promising, because MeV is a human-specific morbillivirus (i.e. without relevant animal reservoir), safe and potent vaccine viruses are sufficiently produced since decades for common application, and millions of vaccine doses have been used globally without any indications of safety and efficacy issues. Though the prevalence of wild-type MeV infection has decreased by >90 % in Europe, measles is still not eliminated and has even re-emerged with recurrent outbreaks in developed countries, in which effective vaccination programmes had been installed for decades. Here, we discuss the crucial factors for a worldwide elimination of MeV: (1) efficacy of current vaccines, (2) the extremely high contagiosity of MeV demanding a >95 % vaccination rate based on two doses to avoid primary vaccine failure as well as the installation of catch-up vaccination programmes to fill immunity gaps and to achieve herd immunity, (3) the implications of sporadic cases of secondary vaccine failure, (4) organisation, acceptance and drawbacks of modern vaccination campaigns, (5) waning public attention to measles, but increasing concerns from vaccine-associated adverse reactions in societies with high socio-economic standards and (6) clinical, epidemiological and virological surveillance by the use of modern laboratory diagnostics and reporting systems. By consequent implementation of carefully designed epidemiologic and prophylactic measures, it should be possible to eradicate MeV globally out of mankind, as the closely related morbillivirus of rinderpest could be successfully eliminated out of the cattle on a global scale.

Towards measles elimination: Phylogenetic analysis of measles viruses in Turkey (2012-2013) and identification of genotype D8

Molecular characterization of different measles virus (MV) strains is essential to combat the disease. Sixty measles MV strains were obtained from throat swabs or urine of patients in Turkey between 2012 and 2013 and characterized. MV RNA sequences (n = 60) were analysed for 456 nucleotides representing hypervariable domain of the nucleoprotein (N) gene. Of the 60 strains analysed 53 were the D8 genotype, 6 were B3, 1 was D4, and 1 was A. This report describes MV genotype D8 that was involved in a measles outbreak in Turkey. Sequences of most genotype D8 strains (n = 51) were identical to the sequence of variant D8-Frankfurt-Main, which has been associated with outbreaks throughout Europe. Despite the lack of epidemiologic information, a phylogenetic analysis suggested that the genotype D8 MV may have been brought to Turkey from elsewhere. Phylogenetic and epidemiological findings suggested that strains identified in tourists and associated with importation included one strain of genotype D8, one strain of genotype B3, and one strain of genotype D4. These findings from the 2012 to 2013 outbreak in Turkey confirm that pockets of unimmunised individuals are making the country susceptible to measles outbreaks. To prevent further outbreaks, deliberate and sustained effort must be made to reach, and immunise susceptible age groups. Towards measles elimination process, continued molecular surveillance of measles strains in Turkey will help identify transmission patterns of virus and evaluate vaccination efforts. J. Med. Virol. 88:1867-1873, 2016. © 2016 Wiley Periodicals, Inc.

Characterization of measles virus strains circulating in Southern Italy (Palermo area, Sicily) between 2010 and 2011

Measles virus (MV) was classified in 24 genotypes that show a distinct geographic distribution. Genotypes contain multiple distinct lineages. In 2011 large outbreaks of measles occurred in Italy and in many European countries. Aims of this study are to analyze the intra-genotype variability and to follow the importation and the spread of new MV strains in Sicily. A fragment of 450 bps of MV C-terminal nucleoprotein was sequenced from sera of 73 Sicilian patients with symptomatic measles infections, occurred between 2010 and 2011. Five MV strains were D4 genotype and 68 were D8 genotype. The MV/D4 sequences were related to MV/D4-Enfield variant. Two lineages of MV/D8 genotypes, related to MV/D8-Villupuram variant and to a strain found in Birmingham in 2006 respectively, were identified. This is the first study that reports the co-circulation of different MV genotypes and lineages in Sicily suggesting multiple origins of the outbreak that occurred during 2010 and 2011 years.

Measles among migrants in the European Union and the European Economic Area

Aims: Progress towards meeting the goal of measles elimination in the EU and the European Economic Area (EEA) by 2015 is being obstructed, as some children are either not immunized on time or never immunized. One group thought to be at increased risk of measles is migrants; however, the extent to which this is the case is poorly understood, due to a lack of data. This paper addresses this evidence gap by providing an overview of the burden of measles in migrant populations in the EU/EEA. Methods: Data were collected through a comprehensive literature review, a country survey of EU/EEA member states and information from measles experts gathered at an infectious disease workshop. Results: Our results showed incomplete data on measles in migrant populations, as national surveillance systems do not systematically record migration-specific information; however, evidence from the literature review and country survey suggested that some measles outbreaks in the EU/EEA were due to sub-optimal vaccination coverage in migrant populations. Conclusions: We conclude that it is essential that routine surveillance of measles cases and measles, mumps and rubella (MMR) vaccination coverage become strengthened, to capture migrant-specific data. These data can help to inform the provision of preventive services, which may need to reach out to vulnerable migrant populations that currently face barriers in accessing routine immunization and health services.

Resurgence of measles in Serbia 2010-2011 highlights the need for supplementary immunization activities

Between December 2010 and August 2011 an outbreak of measles occurred in Serbia with 363 reported cases. Sera and/or nose/throat swabs were collected from 193 patients and tested for measles-specific IgM antibodies by ELISA and viral RNA by RT-PCR, respectively. Epidemiological data were obtained from the surveillance database of the Institute of Public Health of Serbia. Of the 363 cases involved in the outbreak, 113 were laboratory confirmed. More than one third of the patients were hospitalized (n = 130, 35·8%) and for 15 (4·1% of the reported outbreak cases) the infection was complicated by pneumonia. Mostly pre-school children aged ⩽4 years (37·8%) and adults aged ⩾30 years (27·3%) were affected. The majority of patients belonged to the Roma population with a preponderance of female cases (57·0%). Nearly 94% of the patients were either unvaccinated or of unknown vaccination status. The main outbreak virus was the D4-Hamburg strain. The outbreak in Serbia occurred after several years of very low measles incidence despite a high routine immunization coverage in the general population, suggesting that special efforts to identify and vaccinate susceptible population groups are required even in countries with apparently good disease control.

[Immunity against measles among healthcare personnel at the University Hospital Frankfurt, 2003-2013]

BACKGROUND

Despite aiming for the elimination of measles by 2015, the current epidemiological situation in Germany shows that there is still insufficient vaccination coverage among the population. During the present pre-elimination period, nosocomial measles are gaining in importance.

AIM

The purpose of our study was to determine the immune status of measles among healthcare personnel and medical students at the University Hospital Frankfurt. Moreover, the knowledge of study participants regarding the WHO's goal of the elimination of measles and the general attitude towards vaccination recommendations were investigated.

METHODS

A retrospective study of measles seroprevalence was conducted among healthcare personnel and students at the University Hospital Frankfurt with an observation period of 11 years. In spring 2014, medical students were asked to complete an anonymous questionnaire regarding vaccination status, knowledge of measles and acceptance of measles vaccination recommendations.

RESULTS

In total, 9,933 serologies were evaluated and 85.7% of the participants had sufficient immunity against measles. Significant changes in immunity to measles over time were not observed. However, a significant difference in the immunity rate of participants born before 1970 and those born after1970 was found. Participants born before 1970 significantly more often showed sufficient immunity against measles compared to those born later (96.4 vs. 83.3 %, p < 0.0001). Almost 20 % of the medical students were not aware of their measles vaccination status and merely 70.7 % indicated that they had received two measles vaccinations. Furthermore, only 45.4 % of the medical students were familiar with the WHO's goal of eliminating measles by 2015; however 95 % could be classified as vaccination-supporters on the basis of the questionnaire.

CONCLUSIONS

Overall, the immunity rate of measles determined by serology within the study population did not reach the WHO goal of ≥ 95 %, and this gap was even greater in group of medical students. Despite the medical students' positive attitude towards vaccination guidelines, the awareness in this field awaits improvement.

Epidemiology and genetic characterization of measles strains in Senegal, 2004-2013

BACKGROUND

In Senegal, with the variable routine vaccination coverage, the risk for illness and death from measles still exists as evidenced by the measles epidemic episode in 2009. Since 2002 a laboratory-based surveillance system of measles was established by the Ministry of Health and the Institut Pasteur de Dakar. The present study analysed the data collected over the 10 years inclusive between 2004-2013 in order to define a measles epidemiological profile in Senegal, and we carried out a phylogenetic analysis of measles virus circulating in Senegal over the period 2009-2012.

METHODOLOGY AND RESULTS

A total number of 4580 samples were collected from suspected cases, with the most cases between 2008 and 2010 (2219/4580; 48.4%). The majority of suspected cases are found in children from 4-6 years old (29%). 981 (21.4%) were measles laboratory-confirmed by IgM ELISA. The measles confirmation rate per year is very high during 2009-2010 periods (48.5% for each year). Regarding age groups, the highest measles IgM-positivity rate occurred among persons aged over 15 years with 39.4% (115/292) followed by 2-3 years old age group with 30.4% (323/1062) and 30% (148/494) in children under one year old group. The majority of suspected cases were collected between February and June and paradoxically confirmed cases rates increased from July (77/270; 28.6%) and reached a peak in November with 60% (93/155). Phylogenetic analysis showed that all the 29 sequences from strains that circulated in Senegal between 2009 and 2012 belong to the B3 genotype and they are clustered in B3.1 (2011-2012) and B3.3 (2009-2011) sub-genotypes according to a temporal parameter.

CONCLUSION

Improvements in the measles surveillance in Senegal are required and the introduction of oral fluid and FTA cards as an alternative to transportation of sera should be investigated to improve surveillance. The introduction of a national vaccine database including number of doses of measles-containing vaccine will greatly improve efforts to interrupt and ultimately eliminate measles virus transmission in Senegal.

Why are young adults affected? Estimating measles vaccination coverage in 20-34 year old germans in order to verify progress towards measles elimination

BACKGROUND

The introduction of measles vaccination into routine childhood vaccination programmes has led to a shift of disease burden and incidence among young adults. This was confirmed by the recent rise in measles cases and outbreaks throughout Europe. To prevent outbreaks and eliminate measles, one of the key objectives of the WHO Europe measles elimination framework is achieving overall vaccination coverage of ≥95% in the population on a district level. In the absence of national registers, data on vaccination coverage in Germany is recorded at the age of school entry, through insurance refund claim data and population studies. Vaccination status (VS) of young adults is largely unknown.

METHODS

We assessed measles vaccination coverage in young adults aged 20-34 years on a district level of the German Federal State of Rhineland-Palatinate. The knowledge and attitude towards immunization of unvaccinated to vaccinated young adults were compared using Likert questions. We used proportional allocation for stratified random sampling across 36 counties. We mailed a self-administered questionnaire with pre-paid return envelopes along with an offer to complete online. Prior to calculating coverage we tested for non-responder bias using logistic regression.

RESULTS

465 (28%) of 1,637 persons contacted responded (mail: 23%, online: 5%). More women responded than men (odds ratio (OR)=2.1; 95% confidence intervall (CI)=1.7-2.6) but age did not vary between responders and non-responders. Vaccination coverage was 90% (95%CI=87%-93%) for one and 56% (95%CI=51%-61%) for two doses. We found a statistically significant association between receiving two doses and age group. The 20-24 years age group had a 2.3 higher incidence rate ratio (95%CI=1.7-3.2) than the reference group of 30-34 year old to have received two doses of measles vaccination. The group of 25-29 year old had a 1.5 higher incidence rate (95%CI=1.0-2.1) than the reference group to have received two doses of measles vaccination.

CONCLUSIONS

Coverage has failed to reach the WHO Europe elimination goal of 95% measles vaccination in the general population. Targeted approaches including enlistment of occupational health services and checking vaccination status during general practitioner (GP) visits are needed to increase vaccination uptake in this age group in order to achieve measles elimination.

Etiology of maculopapular rash in measles and rubella suspected patients from Belarus

As a result of successful implementation of the measles/rubella elimination program, the etiology of more and more double negative cases remains elusive. The present study determined the role of different viruses as causative agents in measles or rubella suspected cases in Belarus. A total of 856 sera sent to the WHO National Laboratory between 2009 and 2011 were tested for specific IgM antibodies to measles virus (MV), rubella virus (RV) and human parvovirus B19 (B19V). The negatives were further investigated for antibodies to enterovirus (EV) and adenovirus (AdV). Children of up to 3 years were tested for IgM antibodies to human herpesvirus 6 (HHV6). A viral etiology was identified in 451 (52.7%) cases, with 6.1% of the samples being positive for MV; 2.6% for RV; 26.2% for B19V; 9.7% for EV; 4.6% for AdV; and 3.6% for HHV6. Almost all measles and rubella cases occurred during limited outbreaks in 2011 and nearly all patients were at least 15 years old. B19V, EV and AdV infections were prevalent both in children and adults and were found throughout the 3 years. B19V occurred mainly in 3-10 years old children and 20-29 years old adults. EV infection was most common in children up to 6 years of age and AdV was confirmed mainly in 3-6 years old children. HHV6 infection was mostly detected in 6-11 months old infants. Laboratory investigation of measles/rubella suspected cases also for B19V, EV, AdV and HHV6 allows diagnosing more than half of all cases, thus strengthening rash/fever disease surveillance in Belarus.

Seroepidemiology and phylogenetic characterisation of measles virus in Ireland, 2004-2013

BACKGROUND

Ireland is classified as an area of high measles incidence. A World Health Organisation-European Region strategic plan exists for measles elimination by 2015.

OBJECTIVES

To retrospectively investigate measles outbreaks using all patient samples (sera and oral fluid) received for measles laboratory diagnosis and characterise the genetic diversity of circulating measles genotypes in Ireland.

STUDY DESIGN

704 cases of acute measles infection as determined by the presence of measles specific IgM in sera and oral fluids were confirmed at the National Virus Reference Laboratory. Measles positive samples (n=116) were examined by genotyping, sequence analysis and phylogenetic characterisation.

RESULTS

Three measles outbreaks occurred over the study period: 2004, 2009/2010 and 2011. Measles IgM positivity ranged from 22-29% in outbreak years to 5-10% in the intervening years. Age profile analysis revealed that whereas individuals >10 years accounted for only 8% of cases in the 2004 outbreak, this increased to 33% and 29% in the 2009/2010 and 2011 outbreaks, respectively. The <1 year cohort accounted for 18-20% of cases in all outbreaks. Phylogenetic analysis demonstrated both indigenous transmission and also importation events. Clade D viruses were exclusively found circulating in Ireland, with autochthonous transmission of diverse genotype D4 strains associated with large outbreaks across Europe. More recently, genotype D8 was identified and these were associated with importation events.

CONCLUSIONS

This study provides a comprehensive genetic analysis of circulating measles genotypes in Ireland and discriminated between indigenous and imported viral strains. Notably, an increase in laboratory-confirmed measles cases in the greater than 10 years of age group was seen over the study period. This information is valuable to inform vaccination strategies with a focus on those populations who remain susceptible to measles infection.

Wild-type measles viruses with non-standard genome lengths

The length of the single stranded, negative sense RNA genome of measles virus (MeV) is highly conserved at 15,894 nucleotides (nt). MeVs can be grouped into 24 genotypes based on the highly variable 450 nucleotides coding for the carboxyl-terminus of the nucleocapsid protein (N-450). Here, we report the genomic sequences of 2 wild-type viral isolates of genotype D4 with genome lengths of 15,900 nt. Both genomes had a 7 nt insertion in the 3′ untranslated region (UTR) of the matrix (M) gene and a 1 nt deletion in the 5′ UTR of the fusion (F) gene. The net gain of 6 nt complies with the rule-of-six required for replication competency of the genomes of morbilliviruses. The insertions and deletion (indels) were confirmed in a patient sample that was the source of one of the viral isolates. The positions of the indels were identical in both viral isolates, even though epidemiological data and the 3 nt differences in N-450 between the two genomes suggested that the viruses represented separate chains of transmission. Identical indels were found in the M-F intergenic regions of 14 additional genotype D4 viral isolates that were imported into the US during 2007–2010. Viral isolates with and without indels produced plaques of similar size and replicated efficiently in A549/hSLAM and Vero/hSLAM cells. This is the first report of wild-type MeVs with genome lengths other than 15,894 nt and demonstrates that the length of the M-F UTR of wild-type MeVs is flexible.

Complete Genome Sequence of a Wild-Type Measles Virus Isolated during the Spring 2013 Epidemic in Germany

Measles virus induces an acute disease with rash and fever. Despite ongoing vaccination and elimination campaigns, the measles virus still sustains long-lasting transmission chains in Europe. Here we report the complete genome sequence of a wild-type measles virus isolated from a patient in Munich (MVi/Muenchen.DEU/19.13[D8]) during a German measles outbreak in 2013.

Measles outbreak spreading from the community to an anthroposophic school, Berlin, 2011

Between April and July 2011 there was an outbreak of measles virus, genotype D4, in Berlin, Germany. We identified 73 case-patients from the community and among students of an anthroposophic school, who participated in a 4-day school trip, as well as their family and friends. Overall, 27% were aged ≥ 20 years, 57% were female and 15% were hospitalized. Of 39 community case-patients, 38% were aged ≥ 20 years, 67% were female and 63% required hospitalization. Unvaccinated students returning from the school trip were excluded from school, limiting transmission. Within the group of 55 school-trip participants, including 20 measles case-patients, a measles vaccine effectiveness of 97.1% (95% confidence interval 83.4-100) for two doses was estimated using exact Poisson regression. Our findings support school exclusions and the recommendation of one-dose catch-up vaccination for everyone born after 1970 with incomplete or unknown vaccination status, in addition to the two-dose routine childhood immunization recommendation.

Measles in Scotland, 2013

In 2013, Wales and England experienced large outbreaks of measles, a disease that has been targeted by the World Health Organisation for European elimination by 2015. Unfortunately, measles-mumps-rubella vaccine uptake declined to less than 80% in Wales and England after the Wakefield publicity and this resulted in increased population susceptibility to measles. In Scotland, measles-mumps-rubella vaccine uptake dropped to 87% in 2003. Scottish public health efforts in response to this decline aimed to maximise uptake of MMR1 by two years; ensure at least 95% uptake of one dose of measles-mumps-rubella before starting school at age five; and maximise uptake of the second dose of measles-mumps-rubella by age six. Although Scotland has not had any large outbreaks reported to date, transmission of measles from healthcare workers to patients has occurred and reiterates the importance of all healthcare workers accurately knowing their immune status and, when needed, to be fully immunised.

Transmission and molecular characterisation of wild measles virus in Romania, 2008 to 2012

Molecular characterisation of measles virus is a powerful tool for tracing transmission. Genotyping may prove the absence of endemic circulation of measles virus, i.e. transmission for more than 12 months, which is one of the criteria for verifying elimination of the disease. We have genetically characterised measles viruses detected in Romania from 2008 to 2012, focusing on the recent outbreaks from 2010 to 2012 that affected mainly groups with limited access to healthcare and schools. The findings emphasise the importance of genotyping during the different phases of an outbreak. A total of 8,170 cases were notified, and 5,093 (62%) of the 7,559 possible cases were serologically confirmed. RT-PCR was performed for 104 samples: from the 101 positive samples obtained from sporadic measles cases or clusters from different counties, 73 were genotyped. Sporadic measles cases associated with D4 and D5 viruses were observed from2008 to 2009. Genotype D4-Manchester was predominant in 2011 and 2012. In addition, the related variant D4-Maramures and MVs/Limoges.FRA/17.10[D4] and a few D4-Hamburg strains were detected. The detection of several distinct MV-D4 genotypes suggests multiple virus importations to Romania. The outbreak associated with D4 genotype is the second largest outbreak in Romania in less than 10 years.

Rubella virus genotype 1G and echovirus 9 as etiologic agents of exanthematous diseases in Brazil: insights from phylogenetic analysis

The aim of the present study was to identify the rubella virus (RV) and enterovirus (EV) genotypes detected during the Epidemiological Surveillance on Exanthematic Febrile Diseases (VIGIFEX) study and to perform phylogenetic analysis. Ten RV- and four EV-positive oropharyngeal samples isolated from cell culture were subjected to RT-PCR and sequencing. Genotype 1G and echovirus 9 (E-9) was identified in RV- and EV-positive samples, respectively. The RV 1G genotype has been persisting in Brazil since 2000-2001. No evidence of E-9 being involved in exanthematic illness in Brazil has been reported previously. Differential laboratory diagnosis is essential for management of rash and fever disease.

Measles outbreak in Macedonia: epidemiological, clinical and laboratory findings and identification of susceptible cohorts

OBJECTIVES

Despite a 92-99% national vaccination coverage since 2000, the former Yugoslav Republic of Macedonia experienced a large measles outbreak between 2010 and 2011. Here we investigate the characteristics of patients hospitalized during this outbreak at the Clinic of Infectious Diseases in Skopje.

METHODS

Epidemiological, clinical and laboratory data of 284 measles patients, including 251 from Skopje (43.80% of the 573 reported cases) and 33 from elsewhere in Macedonia were collected.

RESULTS

The most affected age groups were children up to 4 years of age and adolescents/adults of 15 years and older. Most patients were unvaccinated (n=263, 92.61%) and many had non-Macedonian nationalities (n=156, 54.93%) or belonged to the Roma ethnicity (n=73, 25.70%). Bronchopneumonia and diarrhea were the most common complications. Eighty-two out of 86 tested patients (95.35%) had measles-specific IgM antibodies. The outbreak was caused by the measles variant D4-Hamburg.

CONCLUSIONS

The epidemic identified pockets of susceptibles in Skopje and indicated that additional vaccination opportunities in particular for people with non-Macedonian nationality and traveler communities are warranted to ensure efficient measles control in Macedonia. The high attack rate among children of less than 1 year suggests that vaccination before 12 months of age should be considered in high risk settings.

[Hot spot: epidemiology of measles and rubella in Germany and the WHO European region]

The elimination of measles and rubella by 2015 is an important goal set by the World Health Organization European Region (WHO/Europa). Since 1991, the incidence of measles in WHO/Europa declined owing to routine childhood vaccination and supplementary immunization activities in the region. However, in many countries of Western Europe elimination of measles and rubella remains a challenge, and every year there are outbreaks with partly long-lasting transmission chains and dissemination of the virus internationally. In Germany, outbreaks occur because of the high proportion of susceptible individuals in specific population groups. In 2011, over 1,600 cases were reported (19.7 per 1,000,000 inhabitants, data from the Robert Koch Institute) whereas in 2012 only 167 cases were reported to the Robert Koch Institute (2 per 1,000,000 inhabitants). It is unclear whether the declining trend will continue in the following years due to improved vaccination coverage or whether number of cases will rise again because of the accumulation of susceptible groups. In Germany, there are currently no representative, country-wide data on rubella; however, data from the eastern federal states provide important epidemiological insights. Outbreaks are seldom reported, but statutory notification of rubella and congenital rubella syndrome was implemented in March 2013. As a result, it will be possible to better assess the epidemiology of rubella in Germany, although a considerable underreporting of rubella cases is anticipated.

Molecular characterization of measles viruses in Turkey (2010-2011): first report of genotype D9 involved in an outbreak in 2011

Genetic characterization of measles viruses (MVs) combined with acquisition of epidemiologic information is essential for measles surveillance programs used in determining transmission pathways. This study describes the molecular characterization of 26 MV strains (3 from 2010, 23 from 2011) obtained from urine or throat swabs harvested from patients in Turkey. MV RNA samples (n = 26) were subjected to sequence analysis of 450 nucleotides comprising the most variable C-terminal region of the nucleoprotein (N) gene. Phylogenetic analysis revealed 20 strains from 2011 belonged to genotype D9, 3 to D4, 2 strains from 2010 to genotype D4 and 1 to genotype B3. This study represents the first report describing the involvement of MV genotype D9 in an outbreak in Turkey. The sequence of the majority of genotype D9 strains was identical to those identified in Russia, Malaysia, Japan, and the UK. Despite lack of sufficient epidemiologic information, the presence of variants observed following phylogenetic analysis suggested that exposure to genotype D9 might have occurred due to importation more than once. Phylogenetic analysis of five genotype D4 strains revealed the presence of four variants. Epidemiological information and phylogenetic analysis suggested that three genotype D4 strains and one genotype B3 strain were associated with importation. This study suggests the presence of pockets of unimmunized individuals making Turkey susceptible to outbreaks. Continuing molecular surveillance of measles strains in Turkey is essential as a means of acquiring epidemiologic information to define viral transmission patterns and determine the effectiveness of measles vaccination programs designed to eliminate this virus.

Obstacles in measles elimination: an in-depth description of a measles outbreak in Ghent, Belgium, spring 2011

Background

From Mid-February to April 2011 one of the largest measles-outbreak in Flanders, since the start of the 2-dose vaccination scheme in 1995, took place in Ghent, Belgium. The outbreak started in a day care center, infecting children too young to be vaccinated, after which it spread to anthroposophic schools with a low measles, mumps and rubella vaccination coverage. This report describes the outbreak and evaluates the control measures and interventions.

Methods

Data collection was done through the system of mandatory notification of the public health authority. Vaccination coverage in the schools was assessed by a questionnaire and the electronic immunization database ‘Vaccinnet’. A case was defined as anyone with laboratory confirmed measles or with clinical symptoms and an epidemiological link to a laboratory confirmed case. Towards the end of the outbreak we only sought laboratory confirmation for persons with an atypical clinical presentation or without an epidemiological link. In search for an index patient we determined the measles IgG level of infants from the day care center.

Results

A total of 65 cases were reported of which 31 were laboratory confirmed. Twenty-five were confirmed by PCR and/or IgM. In 6 infants, too young to be vaccinated, only elevated measles IgG levels were found. Most cases (72%) were young children (0–9 years old). All but two cases were completely unimmunized. In the day care center all the infants who were too young to be vaccinated (N=14) were included as cases. Thirteen of them were laboratory confirmed. Eight of these infants were hospitalized with symptoms suspicious for measles. Vaccination coverage in the affected anthroposophic schools was low, 45-49% of the pupils were unvaccinated. We organized vaccination campaigns in the schools and vaccinated 79 persons (25% of those unvaccinated or incompletely vaccinated).

Conclusions

Clustering of unvaccinated persons, in a day care center and in anthroposophic schools, allows for measles outbreaks and is an important obstacle for the elimination of measles. Isolation measures, a vacation period and an immunization campaign limited the spread of measles within the schools but could not prevent further spread among unvaccinated family members. It was necessary to raise clinicians' awareness of measles since it had become a rare, less known disease and went undiagnosed.

Measles in health-care settings

Despite the availability of an effective and safe vaccine for almost half a century, measles is re-emerging in several developed countries because of the insufficient vaccination coverage among specific subpopulations, the emerging anti-vaccination movement, and the increasing movement of humans across borders. In this context, health-care settings play a critical role in the transmission of infection and generation of numerous cases. Health-care-associated outbreaks may be associated with severe morbidity and mortality among specific groups of patients, disruption of health-care services, and considerable costs. Misdiagnosis or delayed diagnosis of a measles case and inadequate implementation of infection control measures are common in almost all events of nosocomial spread. Measles vaccination of health-care workers is an effective means of prevention of nosocomial measles outbreaks. Eliminating measles by 2010 has not been accomplished. Stronger recommendations and higher vaccination coverage against measles in health-care workers could contribute to eliminate measles in the general population.

Southeastern European Health Network (SEEHN) Communicable Diseases Surveillance: a decade of bridging trust and collaboration

The communicable disease threats and changes that began emerging in south-east Europe in the early 1990s – after a decade of war and while political and health systems region-wide were undergoing dramatic changes – demanded a novel approach to infectious disease surveillance. Specifically, they called for an approach that was focused on cross-border collaboration and aligned with European Union standards and requirements. Thus, the Southeastern European Health network (SEEHN) was established in 2001 as a cooperative effort among the governments of Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Moldova, Montenegro, Romania, Serbia, and the former Yugoslav Republic of Macedonia. In 2002, SEEHN initiated a communicable diseases project aimed at strengthening both national and regional surveillance systems with a focus on cross-border collaboration. Over time, SEEHN has nurtured growth of a regional fabric of SEE experts in communicable diseases surveillance and response who are able to discuss emerging issues and best practices at any time and without being constrained by the rigidity of traditional or existing systems. Main achievements to date include joint preparation of influenza pandemic preparedness plans at both national and regional levels and the introduction of molecular techniques into influenza surveillance laboratories region-wide. Here, we describe the history of the SEEHN communicable disease project; major activities and accomplishments; and future sustainability of the regional infectious disease surveillance network that has emerged and grown over the past decade.

Epidemiology of two large measles virus outbreaks in Catalonia: what a difference the month of administration of the first dose of vaccine makes

Measles cases in the European Region have been increasing in the last decade; this illustrates the challenge of what we are now encountering in the form of pediatric preventable diseases. In Catalonia, autochthonous measles was declared eliminated in the year 2000 as the result of high measles-mumps-rubella vaccine (MMR) coverage for first and second dose (15 mo and 4 y) since the mid-1990s. From then on, sporadic imported cases and small outbreaks appeared, until in 2006-2007 a large measles outbreak affecting mostly unvaccinated toddlers hit the Barcelona Health Region. Consequently, in January 2008, first dose administration of MMR was lowered from 15 to 12 mo of age. A new honeymoon period went by until the end of 2010, when several importations of cases triggered new sustained transmission of different wild measles virus genotypes, but this time striking young adults. The aim of this study is to show the effect of a change in MMR vaccination schedule policy, and the difference in age incidence and hospitalization rates of affected individuals between both outbreaks.   Epidemiologic data were obtained by case interviews and review of medical records. Samples for virological confirmation and genotyping of cases were collected as established in the Measles Elimination plan guidelines. Incidence rate (IR), rate ratio (RR) and their 95% CI and hospitalization rate (HR) by age group were determined. Statistic z was used for comparing proportions. Total number of confirmed cases was 305 in the 2010 outbreak and 381 in the 2006-2007 outbreak; mean age 20 y (SD 14.8 y; 3 mo to 51 y) vs. 15 mo (SD 13.1 y; 1 mo to 50 y). Highest proportion of cases was set in ≥ 25 y (47%) vs. 24.2% in 2006 (p < 0.001). Differences in IR for ≤ 15 mo (49/100,000 vs. 278.2/100,000; RR: 3,9; 95%CI 2,9-5.4) and in overall HR 29.8% vs. 15.7% were all statistically significant (p < 0.001). The change of the month of age for the administration of the first MMR dose proved successful to protect infants. Yet, given the current epidemiological situation, continued awareness and efforts to reach young adult population, especially those at high risk of infection and transmission such as healthcare workers and travelers, are needed to stop the spread of the virus when importations occur.

Vaccine-preventable diseases and their prophylaxis

Global uptake of new vaccines shapes the epidemiology of infections, and in turn this changing epidemiology guides vaccine development. Once introduced, surveillance and monitoring of the impact of vaccines on disease and adverse events is vital for further development. This article reviews the use of vaccines as part of routine health care, vaccines that may be required for entry into a destination country, and vaccines that are recommended because of risk during travel. Considerations and advances in the vaccination of travelers are addressed.

The spread of vaccine-preventable diseases by international travellers: a public-health concern

Vaccine-preventable diseases (VPDs) are costly at both the individual and societal levels. The most common VPDs recorded in travellers are enteric (typhoid or paratyphoid B) fever, acute viral hepatitis, influenza, varicella, measles, pertussis and bacterial meningitis. Travellers suffering from VPDs are frequently hospitalized, illustrating the point that VPDs are serious and expensive. Many travellers are not properly immunized before travel. In addition to individual consequences, VPDs can have public-health consequences if they are introduced or re-introduced by infected travellers returning to areas with susceptible populations. The international spread of poliomyelitis, Neisseria meningitidis serogroup W135 meningococcal infections, measles and influenza provides strong evidence of the role of international travel in the globalization of VPDs. The surveillance of the emergence, re-emergence or spread of VPDs is essential to adapt pre-travel advice and the responses to the VPD.

Seroprevalence of measles-, mumps- and rubella-specific IgG antibodies in German children and adolescents and predictors for seronegativity

We have undertaken a seroprevalence study with more than 13,000 children, who had been included in the German KIGGS survey, a representative sample of children and adolescents 0-17 years of age. The IgG titres against measles, mumps and rubella were determined in 1 to 17 year olds While 88.8% of the children were MMR-vaccinated at least once, 76.8% of children aged 1 to 17 years showed prevalence of antibodies to MMR. The highest seronegativity was seen with respect to mumps. Gender differences were most pronounced with regard to rubella IgG titres: girls aged 14 to 17 years were best protected, although seronegativity in 6.8% of this vulnerable group still shows the need of improvement. Search for predictors of missing seroprevalence identified young age to be the most important predictor. Children living in the former West and children born outside of Germany had a higher risk of lacking protection against measles and rubella, while children with a migration background but born in Germany were less often seronegative to measles antibodies than their German contemporaries. An association of seronegativity and early vaccination was seen for measles but not for mumps and rubella. A high maternal educational level was associated with seronegativity to measles and rubella. In vaccinated children, seronegativity was highest for mumps and lowest for rubella. For mumps, high differences were observed for seronegativity after one-dose and two-dose vaccination, respectively. Seronegativity increases as time since last vaccination passes thus indicating significant waning effects for all three components of MMR.