Vaccine-induced neutralizing antibodies bind to the H protein of a historical measles virus

Measles is a highly contagious airborne viral disease. It can lead to serious complications and death and is preventable by vaccination. The live-attenuated measles vaccine (LAMV) derived from a measles virus (MV) isolated in 1954 has been in use globally for six decades and protects effectively by providing a durable humoral and cell-mediated immunity. Our study addresses the temporal stability of epitopes on the viral surface glycoprotein hemagglutinin (H) which is the major target of MV-neutralizing antibodies. We investigated the binding of seven vaccine-induced MV-H-specific monoclonal antibodies (mAbs) to cell-free synthesized MV-H proteins derived from the H gene sequences obtained from a lung specimen of a fatal case of measles pneumonia in 1912 and an isolate from a current case. The binding of four out of seven mAbs to the H protein of both MV strains provides evidence of epitopes that are stable for more than 100 years. The binding of the universally neutralizing mAbs RKI-MV-12b and RKI-MV-34c to the H protein of the 1912 MV suggests the long-term stability of highly conserved epitopes on the MV surface.

Measles vaccination - An underestimated prevention measure: Analyzing a fatal case in Hildesheim, Germany

Measles and rubella are targeted for elimination in the WHO region Europe. To reach the elimination goal, vaccination coverage of 95% must be achieved and sustained, the genotype information has to be provided for 80% of all outbreaks and transmission chains of a certain variant must not be detected for >12 months. The latter information is collected at Germany's National Reference Center Measles, Mumps, Rubella (NRC MMR). We describe here an outbreak of measles occurring in Hildesheim. The outbreak comprised 43 cases and lasted 14 weeks. Surprisingly, a high number of vaccination failures was observed since 11 cases had received two doses of the MMR vaccine and 4 additional cases were vaccinated once. A 33-year-old woman passed away during the outbreak. She was the mother of 5 children between 4 and 16 years of age. Two schoolchildren contracted measles and passed it on to the rest of the family. Due to delivery bottlenecks, the vaccination of the mother was delayed. She developed measles-like symptoms 3 days after vaccination and was found dead on the morning of day 8 after vaccination. A post-mortem examination was done to identify the cause of death. Moreover, molecular characterization of the virus was performed to analyze whether she was infected by the wildtype virus circulating at that time in Hildesheim or whether the vaccine may have been a concomitant and aggravating feature of her death. The result showed that the samples taken from her at the time of death and during necropsy contained the wildtype measles virus variant corresponding to MVs/Gir Somnath.IND/42.16 (WHO Seq-ID D8-4683) that fueled the Hildesheim outbreak and circulated in Germany from March 2018 to March 2020. The vaccine virus was not detected. Moreover, two aspects uncovered by the post-mortem examination were remarkable; the woman died from giant cell pneumonia, which is a complication seen in immune-suppressed individuals and she was actively using cannabis. THC is known to influence the immune system, but literature reports describing the effects are limited.

A bead-based multiplex assay covering all coronaviruses pathogenic for humans for sensitive and specific surveillance of SARS-CoV-2 humoral immunity

Serological assays measuring antibodies against SARS-CoV-2 are key to describe the epidemiology, pathobiology or induction of immunity after infection or vaccination. Of those, multiplex assays targeting multiple antigens are especially helpful as closely related coronaviruses or other antigens can be analysed simultaneously from small sample volumes, hereby shedding light on patterns in the immune response that would otherwise remain undetected. We established a bead-based 17-plex assay detecting antibodies targeting antigens from all coronaviruses pathogenic for humans: SARS-CoV-2, SARS-CoV, MERS-CoV, HCoV strains 229E, OC43, HKU1, and NL63. The assay was validated against five commercial serological immunoassays, a commercial surrogate virus neutralisation test, and a virus neutralisation assay, all targeting SARS-CoV-2. It was found to be highly versatile as shown by antibody detection from both serum and dried blot spots and as shown in three case studies. First, we followed seroconversion for all four endemic HCoV strains and SARS-CoV-2 in an outbreak study in day-care centres for children. Second, we were able to link a more severe clinical course to a stronger IgG response with this 17-plex-assay, which was IgG1 and IgG3 dominated. Finally, our assay was able to discriminate recent from previous SARS-CoV-2 infections by calculating the IgG/IgM ratio on the N antigen targeting antibodies. In conclusion, due to the comprehensive method comparison, thorough validation, and the proven versatility, our multiplex assay is a valuable tool for studies on coronavirus serology.

Acute orchitis deciphered: Coxsackievirus B strains are the main etiology and their presence in semen is associated with acute inflammation and risk of persistent oligozoospermia

Although various viruses are considered to be the clinical cause for acute orchitis, it is completely unclear to what extent and which viruses are etiologically involved in acute orchitis and what the clinic and course of these patients are like. Therefore, a prospective study was set up to decipher acute isolated orchitis. Between July 2007 and February 2023, a total of 26 patients with isolated orchitis were recruited and compared with 530 patients with acute epididymitis. We were able to show for isolated orchitis, that (1) orchitis is usually of viral origin (20/26, 77%) and enteroviruses with coxsackievirus B strains (16/26, 62%) are predominant, (2) virus isolates could be received from semen indicating the presence of replication-competent virus particles, (3) a polymerase chain reaction (PCR) for enteroviruses should be conducted using semen provided at the onset of disease, because the virus is not detectable in serum/urine, (4) there is a circannual occurrence with the maximum in summer, (5) orchitis is associated with a characteristic inflammatory cytokine panel in the semen and systemic inflammation, (6) orchitis is usually rapidly self-limiting, and (7) about 30% of patients (6/20) suffer ongoing oligozoospermia. These seven emerging aspects are likely to fundamentally change thinking and clinical practice regarding acute isolated orchitis.

ICTV Virus Taxonomy Profile: Matonaviridae 2022

The family Matonaviridae comprises enveloped viruses with positive-sense RNA genomes of 9.6-10 kb. The genus Rubivirus includes rubella virus (species Rubivirus rubellae) infecting humans, ruhugu virus (species Rubivirus ruteetense) infecting bats and rustrela virus (species Rubivirus strelense) infecting rodents and zoo animals. Rubella virus is spread via droplets. Postnatal infection leads to benign disease with rash and fever. Infection of seronegative women with rubella virus during the first trimester of pregnancy will often result in severe foetal malformations, known as congenital rubella syndrome. Vaccines are globally available. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Matonaviridae, which is available at ictv.global/report/matonaviridae.

Detection of measles virus in Bulgaria from 2012 to 2018

AIM

To determine the circulation patterns of measles virus in Bulgaria from 2012 to 2018 after a large measles outbreak in the country (2009-2011).

METHODS

Three types of clinical material were collected: serum samples, urine samples, and nasal swabs. Enzyme-linked immunosorbent assay (ELISA) was used to detect specific viral immunoglobulin (Ig) M/IgG antibodies. Viral RNA was extracted from all urine and nasal swabs.

RESULTS

In the investigated period, 102 patients were confirmed to have measles (age range: two months to 55 years). A total of 101 samples (99%) were measles-IgM positive. Most of them were detected in 2017 (73%, 74/101), when a measles outbreak in the country was reported. The majority of patients were unvaccinated children aged under 13 months. Out of 101 measles serum samples confirmed by ELISA, 18 (20.45%) were measles-IgG positive and 15 (17.05%) were borderline. Thirty-three positive PCR products were sequenced and genotyped. In 2013, 2016, 2017, and 2018, three different measles viral genotypes were detected: D8, H1, and B3. Most patients were unvaccinated or insufficiently vaccinated.

CONCLUSION

Preventive measures are indispensable to limit the infection in different regions of Bulgaria and its spread to other countries. As vaccination coverage against measles and other vaccine-preventable infections, including SARS-Co2, is low, it is necessary to perform molecular identification of viruses to monitor their circulation and pathogenicity.

Corrigendum: Specifically increased rate of infections in children post measles in a high resource setting

[This corrects the article DOI: 10.3389/fped.2022.896086.].

Specifically Increased Rate of Infections in Children Post Measles in a High Resource Setting

OBJECTIVES

Post-measles increased susceptibility to subsequent infections seems particularly relevant in low-resource settings. We tested the hypothesis that measles causes a specifically increased rate of infections in children, also in a high-resource setting.

METHODS

We conducted a retrospective cohort study on a large measles outbreak in Berlin, Germany. All children with measles who presented to hospitals in Berlin were included as cases, children with non-infectious and children with non-measles infectious diseases as controls. Repeat visits within 3 years after the outbreak were recorded.

RESULTS

We included 250 cases, 502 non-infectious, and 498 infectious disease controls. The relative risk for cases for the diagnosis of an infectious disease upon a repeat visit was 1.6 (95% CI 1.4-2.0, p < 0.001) vs. non-infectious and 1.3 (95% CI 1.1-1.6, p = 0.002) vs. infectious disease controls. 33 cases (27%), 35 non-infectious (12%) and 57 (18%) infectious disease controls presented more than three times due to an infectious disease (p = 0.01, and p = 0.02, respectively). This results in a relative risk of more than three repeat visits due to an infection for measles cases of 1.8 (95% CI 1.3-2.4, p = 0.01), and 1.4 (95% CI 1.0-1.9, p = 0.04), respectively.

CONCLUSION

Our study demonstrates for the first time in a high-resource setting, that increased post-measles susceptibility to subsequent infections in children is measles-specific-even compared to controls with previous non-measles infections.

Small-molecule polymerase inhibitor protects non-human primates from measles and reduces shedding

Measles virus (MeV) is a highly contagious pathogen that enters the human host via the respiratory route. Besides acute pathologies including fever, cough and the characteristic measles rash, the infection of lymphocytes leads to substantial immunosuppression that can exacerbate the outcome of infections with additional pathogens. Despite the availability of effective vaccine prophylaxis, measles outbreaks continue to occur worldwide. We demonstrate that prophylactic and post-exposure therapeutic treatment with an orally bioavailable small-molecule polymerase inhibitor, ERDRP-0519, prevents measles disease in squirrel monkeys (Saimiri sciureus). Treatment initiation at the onset of clinical signs reduced virus shedding, which may support outbreak control. Results show that this clinical candidate has the potential to alleviate clinical measles and augment measles virus eradication.

Measles virus is highly contagious and outbreaks occur worldwide. Here the authors show that the orally bioavailable small-molecule polymerase inhibitor ERDRP-0519 prevents measles disease in squirrel monkeys and reduces virus shedding.

Seroprevalence of Measles-, Mumps-, and Rubella-specific antibodies in the German adult population - cross-sectional analysis of the German Health Interview and Examination Survey for Adults (DEGS1)

BACKGROUND

The WHO European Region targets the elimination of measles, rubella, and the congenital rubella syndrome and welcomes mumps elimination via the joint MMR vaccine. In a push towards this elimination goal, Germany introduced a recommendation on MMR vaccination for adults in 2010 to prevent increasing numbers of measles cases among adults and to strengthen herd immunity.

METHODS

The prevalence of anti-measles, -mumps, and -rubella IgG antibodies was analysed in 7,115 participants between the ages of 18 and 79 years in the German Health Interview and Examination Survey. Risk factors of seronegativity of adults born 1970 or later were determined.

FINDINGS

The seroprevalence of anti-measles IgG antibodies was more than 97% in adults born before 1965 and less than 90% in adults born afterwards. Prevalence and GMTs declined with later years of birth. Seronegativity was associated with two-sided migration background and region of residence in East Germany. For anti-mumps IgG antibodies, the seroprevalence was less than 90% in almost all age groups. Prevalence and GMTs declined with later years of birth. Seronegativity was not associated with any socio-demographic factor. Anti-rubella IgG seropositivity was found in more than 90% of adults born before 1985. GMTs declined in younger age groups. Seronegativity was associated with birth between 1980 and 1993 and male gender. High socio-economic status lowered the odds of being seronegative.

INTERPRETATION

These data reinforce the implementation of the vaccination recommendation for adults and provide the basis for further evaluation of this measure.

FUNDING

The Federal Ministry of Health, Germany.

Measles virus and rinderpest virus divergence dated to the sixth century BCE

Many infectious diseases are thought to have emerged in humans after the Neolithic revolution. Although it is broadly accepted that this also applies to measles, the exact date of emergence for this disease is controversial. We sequenced the genome of a 1912 measles virus and used selection-aware molecular clock modeling to determine the divergence date of measles virus and rinderpest virus. This divergence date represents the earliest possible date for the establishment of measles in human populations. Our analyses show that the measles virus potentially arose as early as the sixth century BCE, possibly coinciding with the rise of large cities.

A Placenta Derived C-Terminal Fragment of β-Hemoglobin With Combined Antibacterial and Antiviral Activity

The placenta acts as physical and immunological barrier against the transmission of viruses and bacteria from mother to fetus. However, the specific mechanisms by which the placenta protects the developing fetus from viral and bacterial pathogens are poorly understood. To identify placental peptides and small proteins protecting from viral and bacterial infections, we generated a peptide library from 10 kg placenta by chromatographic means. Screening the resulting 250 fractions against Herpes-Simplex-Virus 2 (HSV-2), which is rarely transmitted through the placenta, in a cell-based system identified two adjacent fractions with significant antiviral activity. Further rounds of chromatographic purification and anti-HSV-2 testing allowed to purify the bioactive peptide. Mass spectrometry revealed the presence of a 36-mer derived from the C-terminal region of the hemoglobin β subunit. The purified and corresponding chemically synthesized peptide, termed HBB(112–147), inhibited HSV-2 infection in a dose-dependent manner, with a mean IC₅₀ in the median μg/ml range. Full-length hemoglobin tetramer had no antiviral activity. HBB(112–147) did not impair infectivity by direct targeting of the virions but prevented HSV-2 infection at the cell entry level. The peptide was inactive against Human Immunodeficiency Virus Type 1, Rubella and Zika virus infection, suggesting a specific anti-HSV-2 mechanism. Notably, HBB(112–147) has previously been identified as broad-spectrum antibacterial agent. It is abundant in placenta, reaching concentrations between 280 and 740 μg/ml, that are well sufficient to inhibit HSV-2 and prototype Gram-positive and -negative bacteria. We here additionally show, that HBB(112–147) also acts potently against Pseudomonas aeruginosa strains (including a multi-drug resistant strain) in a dose dependent manner, while full-length hemoglobin is inactive. Interestingly, the antibacterial activity of HBB(112–147) was increased under acidic conditions, a hallmark of infection and inflammatory conditions. Indeed, we found that HBB(112–147) is released from the hemoglobin precursor by Cathepsin D and Napsin A, acidic proteases highly expressed in placental and other tissues. We propose that upon viral or bacterial infection, the abundant hemoglobin precursor is proteolytically processed to release HBB(112–147), a broadly active antimicrobial innate immune defense peptide.

Hospital outbreak of measles - Evaluation and costs of 10 occupational cases among healthcare worker in Germany, February to March 2017

After treatment of an inpatient with measles, an outbreak occurred within the unprotected healthcare workers (HCW) of a regional hospital in Hesse, Germany in February and March 2017. Overall, 10 HCW contracted measles. Remarkably, none of the affected HCW had direct contact to the index patient. One nosocomial transmission to a patient occurred. The economic impact of the outbreak is estimated to approximately 700,000€. Medical institutions play a major role in the management of measles outbreaks, since the risk of exposure as well as nosocomial transmission to vulnerable patients and HCW is very high. To avoid outbreaks it is essential to have an easily accessible documentation of the immune-status of all HCW. The role of occupational medicine in identifying and closing vaccination gaps is of particular importance.

Rubella Viruses Shift Cellular Bioenergetics to a More Oxidative and Glycolytic Phenotype with a Strain-Specific Requirement for Glutamine

The flexible regulation of cellular metabolic pathways enables cellular adaptation to changes in energy demand under conditions of stress such as posed by a virus infection. To analyze such an impact on cellular metabolism, rubella virus (RV) was used in this study. RV replication under selected substrate supplementation with glucose, pyruvate, and glutamine as essential nutrients for mammalian cells revealed its requirement for glutamine. The assessment of the mitochondrial respiratory (based on the oxygen consumption rate) and glycolytic (based on the extracellular acidification rate) rate and capacity by respective stress tests through Seahorse technology enabled determination of the bioenergetic phenotype of RV-infected cells. Irrespective of the cellular metabolic background, RV infection induced a shift of the bioenergetic state of epithelial cells (Vero and A549) and human umbilical vein endothelial cells to a higher oxidative and glycolytic level. Interestingly there was a RV strain-specific, but genotype-independent demand for glutamine to induce a significant increase in metabolic activity. While glutaminolysis appeared to be rather negligible for RV replication, glutamine could serve as donor of its amide nitrogen in biosynthesis pathways for important metabolites. This study suggests that the capacity of RVs to induce metabolic alterations could evolve differently during natural infection. Thus, changes in cellular bioenergetics represent an important component of virus-host interactions and could complement our understanding of the viral preference for a distinct host cell population.IMPORTANCE RV pathologies, especially during embryonal development, could be connected with its impact on mitochondrial metabolism. With bioenergetic phenotyping we pursued a rather novel approach in virology. For the first time it was shown that a virus infection could shift the bioenergetics of its infected host cell to a higher energetic state. Notably, the capacity to induce such alterations varied among different RV isolates. Thus, our data add viral adaptation of cellular metabolic activity to its specific needs as a novel aspect to virus-host evolution. In addition, this study emphasizes the implementation of different viral strains in the study of virus-host interactions and the use of bioenergetic phenotyping of infected cells as a biomarker for virus-induced pathological alterations.

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.

Varicella-zoster virus seroprevalence in children and adolescents in the pre-varicella vaccine era, Germany

Background

In 2004, universal childhood varicella vaccination was introduced in Germany. We aimed to determine the age-specific prevalence of anti-varicella zoster virus (VZV) IgG-antibodies among children in the pre-varicella vaccine era in Germany, to identify factors associated with VZV seropositivity, and to assess the suitability of a commercially available ELISA for VZV seroepidemiological studies by comparing it with an in-house fluorescent antibody to membrane antigen test (FAMA) as the gold standard.

Methods

Serum samples of 13,433 children and adolescents aged 1–17 years included in the population-based German Health Interview and Examination Survey for Children and Adolescents (KiGGS; conducted 2003–2006) were tested for anti-VZV IgG by ELISA. All samples with equivocal ELISA results and a random selection of ELISA-negative and -positive samples were tested by FAMA. Statistical analyses were conducted using a weighting factor adjusting the study population to the total population in Germany. Seroprevalences were calculated as percentages (%) with a 95% confidence interval (CI). Odds ratios (OR) were computed by multivariate logistic regression to determine the association between socio-demographic factors and VZV seropositivity.

Results

The VZV seropositivity rate was 80.3% (95% CI: 79.3–81.3) in varicella-unvaccinated children and adolescents. VZV seropositivity rates differed significantly between age groups up to age 6 years, but not by gender. Of 118 retested serum samples with an equivocal ELISA result, 45.8% were FAMA-positive. The proportion of samples tested as false-negative in by ELISA varied by age group: 2.6% in children aged 1–6 and 9% in children aged 7–17 years. Multivariate analyses showed that age, having older siblings, and early daycare start were associated with seropositivity in preschoolers; migration background reduced the chance of VZV seropositivity in schoolchildren (OR: 0.65; 0.43–0.99) and adolescents (OR: 0.62; 0.4–0.97).

Conclusion

In the pre-varicella vaccine era, most children in Germany contracted varicella by age six. Schoolchildren with a migration background and children without siblings have an increased risk of being VZV seronegative and should be targeted for catch-up vaccination, if they have no history of chickenpox. ELISAs are suitable for use in population-level serosurveys on VZV, but samples with equivocal ELISA results should be retested by FAMA.

Porcine Circoviruses and Xenotransplantation

Allotransplantation and xenotransplantation may be associated with the transmission of pathogens from the donor to the recipient. Whereas in the case of allotransplantation the transmitted microorganisms and their pathogenic effect are well characterized, the possible influence of porcine microorganisms on humans is mostly unknown. Porcine circoviruses (PCVs) are common in pig breeds and they belong to porcine microorganisms that still have not been fully addressed in terms of evaluating the potential risk of xenotransplantation using pig cells, tissues, and organs. Two types of PCVs are known: porcine circovirus (PCV) 1 and PCV2. Whereas PCV1 is apathogenic in pigs, PCV2 may induce severe pig diseases. Although most pigs are subclinically infected, we do not know whether this infection impairs pig transplant functionality, particularly because PCV2 is immunosuppressive. In addition, vaccination against PCV2 is able to prevent diseases, but in most cases not transmission of the virus. Therefore, PCV2 has to be eliminated to obtain xenotransplants from uninfected healthy animals. Although there is evidence that PCV2 does not infect—at least immunocompetent—humans, animals should be screened using sensitive methods to ensure virus elimination by selection, Cesarean delivery, vaccination, or embryo transfer.

Challenges of measles and rubella laboratory diagnostic in the era of elimination

The Member States of the WHO European Region adopted the goal of measles and rubella elimination more than 10 years ago, but so far only 21 of 53 countries have reached this target. Laboratory investigation of suspected cases is essential to support disease elimination efforts. Therefore, WHO maintains a network of accredited laboratories providing high-quality testing. Laboratory investigation heavily relies on specific IgM serology and increasingly on virus detection by reverse transcription (RT)-PCR, but other methods such as IgG avidity testing and genetic characterization of virus strains have gained in importance. In elimination settings, often few samples from suspected cases are available for testing, but testing proficiency must be maintained. The predictive value of an IgM-positive result decreases and other rash-fever disease aetiologies become more important. In addition, cases with a rash after measles/rubella vaccination or with mild disease after waning of vaccine-induced antibodies are seen more often. Thus, it is necessary to perform comprehensive and potentially time-consuming and costly investigations of every suspected case using quality-controlled laboratory methods. At the same time rapid feedback to public health officers is required for timely interventions. The introduction of new laboratory methods for comprehensive case investigations requires training of staff under the supervision of WHO-accredited reference laboratories and the definition of appropriate test algorithms. Clinical, laboratory, and epidemiological data are essential for final case classification and investigation of chains of transmission in the endgame of measles and rubella elimination.

Epidemiological and molecular investigation of a rubella outbreak, Romania, 2011 to 2012

We describe a rubella outbreak that occurred in Romania between September 2011 and December 2012. During this period 24,627 rubella cases, 41.1% (n=10,134) of which female, were notified based on clinical criteria, and a total of 6,182 individuals were found serologically positive for IgM-specific rubella antibody. The median age of notified cases was 18 years (range: <1-65) and the most affected age group 15 to 19 years (n=16,245 cases). Of all notified cases, 24,067 cases (97.7%) reported no history of vaccination. Phylogenetic analysis of 19 sequences (739 nucleotides each), from 10 districts of the country revealed that the outbreak was caused by two distinct rubella virus strains of genotype 2B, which co-circulated with both temporal and geographical overlap. In addition to the 6,182 IgM-positive rubella cases, 28 cases of congenital rubella syndrome (CRS) were identified, including 11 neonatal deaths and one stillbirth. The outbreak underscores the need to encourage higher vaccination uptake in the population, particularly in women of reproductive age, and to strengthen epidemiological and laboratory investigations of suspected rubella cases. Genetic characterisation of wild-type rubella virus is an essential component to enhance surveillance and here we report rubella virus sequences from Romania.

A sensitive one-step TaqMan amplification approach for detection of rubella virus clade I and II genotypes in clinical samples

Although teratogenic rubella virus (RV) causes a vaccine-preventable disease, it is still endemic in several countries worldwide. Thus, there is a constant risk of RV importation into non-endemic areas. RV monitoring, especially during measles and Zika virus outbreaks, requires reliable diagnostic tools. For this study, a TaqMan-based one-step reverse transcription-quantitative PCR (RT-qPCR) assay, with the p90 gene as a novel and so far unexplored target for detection of clade I and II genotypes, was developed and evaluated. Automated nucleic acid extraction was carried out. Performance characteristics of the TaqMan RT-qPCR assay were determined for a RV plasmid standard and RNA extracted from virus-infected cell culture supernatants representing clade I and II genotypes. Diagnostic specificity and sensitivity were validated against other RNA and DNA viruses, relevant for RV diagnostic approaches and for RV-positive clinical samples, respectively. The assay is specific and highly sensitive with a limit of detection as low as five to one copies per reaction or 200 infectious virus particles per ml. The coefficients of variation (CV) were specified as intra- (within one run) and inter- (between different runs) assay variation, and calculated based on the standard deviations for the obtained Ct values of the respective samples. Intra- and inter-assay CV values were low, with a maximum of 3.4% and 2.4%, respectively. The assay was shown to be suitable and specific for the analysis of clinical samples. With p90 as a novel target, the highly sensitive and specific TaqMan assay outlined in this study is suitable for RV diagnosis worldwide.

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.

The expression level of gC1qR is down regulated at the early time of infection with porcine circovirus of type 2 (PCV-2) and gC1qR interacts differently with the Cap proteins of porcine circoviruses

Porcine circoviruses (PCV) are small, non-enveloped single-stranded DNA-viruses. Porcine circovirus type 2 (PCV-2) is the causal agent of post-weaning multisystemic wasting syndrome (PMWS) whereas porcine circovirus of type 1 (PCV-1) is non- pathogenic. gC1qR is a membrane-located receptor of the complement protein subunit C1q and interacts with PCV capsid proteins. The mechanisms associated with the triggering of PMWS are not well known and gC1qR may have a role in the life cycle and eventually in the pathogenicity of PCV. The objectives of this study were to determine the level of expression of gC1qR during early PCV-2 infection, to determine the region of PCV-2 capsid protein (Cap) required for the interaction with gC1qR and to evaluate the interaction of gC1qR with Cap proteins of different PCV strains. The results indicate that gC1qR transcripts are downregulated in the tonsils and the tracheo-bronchial lymph nodes of piglets infected by PCV-2 at the early time of the infection. The N-terminal amino acids (a.a. 1-59) of PCV-2b Cap, an arginine rich region, are involved in the interaction with gC1qR. Porcine gC1qR interacts with Cap proteins of two pathogenic viral strains, PCV-2a and PCV-2b, while interaction has been observed with only one Cap protein of two investigated strains of PCV-1. The amino acids 30 and 49 of PCV-1Cap, solely, were not responsible of the difference of interaction observed. We have also shown that gC1qR interacts strongly with PCV-2Caps and PCV-1 GER Cap. This result suggests that the different interaction of gC1qR with PCV Cap proteins may have an impact on the pathogenicity of the PCV.

Gene expression profiling of rubella virus infected primary endothelial cells of fetal and adult origin

BACKGROUND

Rubella virus (RV) infection is usually a mild illness in children and adults. However, maternal infection during the first trimester of pregnancy can lead to congenital rubella syndrome (CRS) in the infant. Fetuses with CRS show damage to the endothelium of the heart and blood vessels; thus, it has been speculated that the clinical manifestations associated with CRS may be a result of endothelial cells persistently infected with RV. Here, we compared the effects of RV infection on gene expression in primary endothelial cells of fetal (HUVEC) and of adult (HSaVEC) origin by transcriptional profiling.

RESULTS

More than 75 % of the genes differentially regulated following RV infection were identical in both cell types. Gene Ontology (GO) analysis of these commonly regulated genes showed an enrichment of terms involved in cytokine production and cytokine regulation. Increased accumulation of inflammatory cytokines following RV infection was verified by protein microarray. Interestingly, the chemokine CCL14, which is implicated in supporting embryo implantation at the fetal-maternal interface, was down-regulated following RV infection only in HUVEC. Most noticeably, when analyzing the uniquely regulated transcripts for each cell type, GO term-based cluster analysis of the down-regulated genes of HUVEC revealed an enrichment of the GO terms "sensory organ development", "ear development" and "eye development".

CONCLUSION

Since impairment in vision and hearing are the most prominent clinical manifestations observed in CRS patients, the here detected down-regulated genes involved in the development of sensory organs sheds light on the molecular mechanisms that may contribute to the teratogenic effect of RV.

Cytomegalovirus Seroprevalence Among Children and Adolescents in Germany: Data From the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), 2003-2006

CMV seroprevalence increases with age and is significantly associated with migration background, country of origin, and place of birth. We identified the birth order of siblings, breastfeeding, early day care attendance and living in East Germany as further risk factors.

Background. Congenital cytomegalovirus (CMV) infection can cause severe birth defects. The majority of children with congenital CMV are born to CMV-seropositive women; however, transmission from mother to fetus and resulting defects are more likely to occur when mothers experience seroconversion during pregnancy. The objective of this study was to provide a population-based estimate of CMV seropositivity and to identify factors that correlate with the detection of CMV-immunoglobulin (Ig)G antibodies.

Methods. Cytomegalovirus-specific IgG antibodies were determined by enzyme-linked immunosorbent assay in 13 876 serum samples from children and adolescents (aged 1–17 years). Cytomegalovirus seroprevalence was correlated with children's age, gender, migration background, country of origin, place of birth, socioeconomic status, breast feeding, daycare attendance, order and number of siblings, and residence in East versus West Germany.

Results. Age-adjusted seroprevalence was 27.4% (95% confidence interval, 25.8–29.0). Cytomegalovirus seroprevalence increased with age (21.5% at ages 1–2; 32.0% at ages 14–17). Cytomegalovirus seropositivity was significantly associated with migration background, country of origin and place of birth, and (among migrants only) with low socioeconomic status. Risk factors for CMV acquisition included the birth order of siblings, breastfeeding, early daycare attendance, and living in East Germany.

Conclusions. In Germany, CMV seroprevalence increases with age, irrespective of gender. These data highlight risk factors associated with seroprevalence and help to identify a target age for the application of a CMV vaccine.

Activation of the Mitochondrial Apoptotic Signaling Platform during Rubella Virus Infection

Mitochondria- as well as p53-based signaling pathways are central for the execution of the intrinsic apoptotic cascade. Their contribution to rubella virus (RV)-induced apoptosis was addressed through time-specific evaluation of characteristic parameters such as permeabilization of the mitochondrial membrane and subsequent release of the pro-apoptotic proteins apoptosis-inducing factor (AIF) and cytochrome c from mitochondria. Additionally, expression and localization pattern of p53 and selected members of the multifunctional and stress-inducible cyclophilin family were examined. The application of pifithrin μ as an inhibitor of p53 shuttling to mitochondria reduced RV-induced cell death to an extent similar to that of the broad spectrum caspase inhibitor z-VAD-fmk (benzyloxycarbonyl-V-A-D-(OMe)-fmk). However, RV progeny generation was not altered. This indicates that, despite an increased survival rate of its cellular host, induction of apoptosis neither supports nor restricts RV replication. Moreover, some of the examined apoptotic markers were affected in a strain-specific manner and differed between the cell culture-adapted strains: Therien and the HPV77 vaccine on the one hand, and a clinical isolate on the other. In summary, the results presented indicate that the transcription-independent mitochondrial p53 program contributes to RV-induced apoptosis.

[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.

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

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

Acute epididymitis revisited: impact of molecular diagnostics on etiology and contemporary guideline recommendations

BACKGROUND

Acute epididymitis is a common infectious disease of unknown etiology in about 30% of cases with guidelines based on studies published >15 yr ago.

OBJECTIVE

To investigate the etiology of acute epididymitis using state-of-the-art methods and to provide rational data for antimicrobial therapy and clinical management.

DESIGN, SETTING, AND PARTICIPANTS

Between 2007 and 2013, 237 patients (150 antimicrobially naive and 87 antibiotically pretreated) with acute epididymitis underwent comprehensive investigation comprising microbiologic cultures, polymerase chain reaction (PCR) for sexually transmitted infections (STIs), 16S ribosomal DNA (rDNA) analysis, and PCR detection of 23 viruses. Clinical management followed international guidelines.

OUTCOME MEASURES AND STATISTICAL ANALYSIS

Etiology, clinical management, and outcome after 3 mo were assessed.

RESULTS AND LIMITATIONS

A causative pathogen, predominantly Escherichia coli (56%), was identified in 132 antibiotic-naive patients (88%) and 44 pretreated patients (51%); 16S rDNA analysis increased the detection rate by 10%. STIs were present in 34 cases (14%) (25 patients with Chlamydia trachomatis) and were not restricted to a specific age group. Enteroviruses were found in only two patients (1%). In naive patients, cultured bacteria were susceptible to fluoroquinolones and group 3 cephalosporins in >85% of cases (preateted patients: 42% and 67%, respectively). Primary empirical therapy was continued in 88% of naive patients for 11 d and in 77% of pretreated patients for 13 d with indwelling urinary catheters, rendering patients as high risk for switching. Only six patients (2.5%) underwent semicastration. Prostate-specific antigen levels halved within 3 mo, except in patients who were antibiotic naive and without detected pathogens. Study limitations included a lack of susceptibility testing in cases of STIs.

CONCLUSIONS

Even in antimicrobially pretreated patients, acute epididymitis is mainly of bacterial origin. STIs are not limited to patients aged <35 yr. Viral epididymitis seems a rare condition. Current guideline recommendations on empirical antimicrobial therapy are adequate.

PATIENT SUMMARY

Patients with acute epididymitis should receive appropriate diagnostics and antimicrobial therapy for safe conservative management.

Measles virus spread initiated at international mass gatherings in Europe, 2011

Binary file ES_Abstracts_Final_ECDC.txt matches

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.

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.

Description of measles D4-Hamburg outbreak in Hamburg, Germany, December 2008 to June 2009, which disproportionally affected a local Roma community

From December 2008 to June 2009 a measles outbreak occurred in the Federal State of Hamburg, Germany. The outbreak affected 216 persons and was caused by a new measles strain termed D4-Hamburg which led to consecutive outbreaks between 2009 and 2011 in at least 12 European countries. Here, we describe epidemiological characteristics of the outbreak and evaluate the control measures taken in Hamburg. In one of the seven boroughs of Hamburg a local Roma community comprised more than 50% of the notified cases.We compared in a stratified analysis the age distribution of these cases with cases of fellow citizens who did not belong to the Roma community. The age group of infants (0-11 months) comprised 33% among the non-Roma measles cases, while in the Roma community only 4% belonged to this stratum. In the stratum of 5-17 year-olds only 8% were affected among the non-Roma cases, whereas in the Roma community 50% belonged to this age group. We discuss the influencing factors that might have led to this difference in age distribution between the two groups.

Description of measles D4-Hamburg outbreak in Hamburg, Germany, December 2008 to June 2009, which disproportionally affected a local Roma community

From December 2008 to June 2009 a measles outbreak occurred in the Federal State of Hamburg, Germany. The outbreak affected 216 persons and was caused by a new measles strain termed D4-Hamburg which led to consecutive outbreaks between 2009 and 2011 in at least 12 European countries. Here, we describe epidemiological characteristics of the outbreak and evaluate the control measures taken in Hamburg. In one of the seven boroughs of Hamburg a local Roma community comprised more than 50% of the notified cases. We compared in a stratified analysis the age distribution of these cases with cases of fellow citizens who did not belong to the Roma community. The age group of infants (0-11 months) comprised 33% among the non-Roma measles cases, while in the Roma community only 4% belonged to this stratum. In the stratum of 5-17 year-olds only 8% were affected among the non-Roma cases, whereas in the Roma community 50% belonged to this age group. We discuss the influencing factors that might have led to this difference in age distribution between the two groups.

Two consecutive measles outbreaks with genotypes D8 and D4 in two mainly unvaccinated communities in Germany

A measles infection in a 13-year-old student from a free progressive school was the index case for an outbreak in Essen in 2010. In this type of school, mainly unvaccinated and measles-susceptible children accumulate. This observation is confirmed by the fact that some of the recent outbreaks originated in such institutions. In Essen, this outbreak was followed by a second smaller outbreak in unvaccinated children and adults in a low socio-economic setting and migration background. Measles were diagnosed clinically and/or were serologically confirmed. Genotyping of measles isolates was performed by PCR and sequencing. Vaccination certificates were checked by the Community Health Centre (CHC) of the City of Essen. Measures to prevent the spread of the infection were implemented and enforced according to the National Protection Against Infection Act (IfSG). In total, 86 cases of measles were notified from March to July 2010. Of all infected patients, 97 % had had no vaccination and 15 % had to be hospitalised. Clinical courses showed the severity of this infection. Epidemiologic evaluation and genotyping of measles virus (MV) detected in Essen revealed the presence of two distinct chains of MV transmission by genotypes D8 and D4 causing two independent outbreaks. The outbreaks were caused by the index cases, and the spread of infection was facilitated by insufficient vaccination coverage in certain groups. Immediate suspension of non-immune children from classes for 2 weeks might have limited the outbreak in the free progressive school. Overall, high measles vaccination coverage in children and adolescents in regular schools in Essen presumably prevented a greater spread of the virus.

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

A new strain of measles virus, D4-Hamburg, was imported from London to Hamburg in December 2008 and subsequently spread to Bulgaria, where an outbreak of >24,300 cases was observed. We analyzed spread of the virus to demonstrate the importance of addressing hard-to-reach communities within the World Health Organization European Region regarding access to medical care and vaccination campaigns. The D4-Hamburg strain appeared during 2009-2011 in Poland, Ireland, Northern Ireland, Austria, Greece, Romania, Turkey, Macedonia, Serbia, Switzerland, and Belgium and was repeatedly reimported to Germany. The strain was present in Europe for >27 months and led to >25,000 cases in 12 countries. Spread of the virus was prevalently but not exclusively associated with travel by persons in the Roma ethnic group; because this travel extends beyond the borders of any European country, measures to prevent the spread of measles should be implemented by the region as a whole.

Closer to the goal: efforts in measles elimination in Germany 2010

Increasing 2-dose vaccination coverage has led to an interruption of endemic measles virus circulation in Germany. However, outbreaks after virus importation still occur and contribute to international transmission chains. Between 2003 and 2009, annual measles incidence ranged between 0.2 and 2.8 per 100,000 population. Immunization gaps have been identified especially in secondary-school students and young adults, which is also reflected by a shift in age distribution of reported measles cases toward older age groups. Stronger political commitment and standardized guidelines for outbreak containment were put in place in Germany in the past years, but the last step toward measles elimination cannot be made until the number of susceptible individuals has been further reduced. In addition to routine childhood vaccination, supplementary immunization activities are needed targeting school students and young adults to close critical immunization gaps. Intensification of public awareness and sound information on vaccinations are necessary to convince skeptics and remind the forgetful.

Molecular genotyping and epidemiology of measles virus transmission in the World Health Organization European Region, 2007-2009

BACKGROUND

In 2002, the World Health Organization (WHO) adopted a goal to eliminate measles in the European Region by 2010. Measles elimination is defined as the interruption of indigenous measles virus (MV) transmission. The molecular epidemiology of MV transmission in the WHO European Region was studied through the investigation of reported cases and outbreaks to monitor the region's progress toward its measles elimination goal.

METHODS

National and regional laboratories performed molecular characterization of MV detected between 2007 and 2009 in the WHO European Region. To document indigenous transmission and importations into the region, we analyzed genotyping results and epidemiological data on measles outbreaks reported by the member states.

RESULTS

Since 2007, MV genotype D6 has not been reported in the WHO European Region, suggesting that its chains of transmission have been interrupted, whereas several other MV genotypes are still circulating. Although several European countries have already interrupted indigenous MV transmission, genotyping showed that 3 endemic MV transmission chains have been reestablished in other countries.

CONCLUSIONS

The WHO European Region 2010 goal will not be met, as indigenous transmission of MV has not been interrupted. As the region begins to document its process of elimination verification to monitor progress toward the goal, countries will need to ensure that genotyping is performed in all measles outbreaks.

Measles transmission from an anthroposophic community to the general population, Germany 2008

BACKGROUND

In Germany, measles vaccination coverage with two doses is not yet sufficient to prevent regional outbreaks. Among the 16 German federal states, vaccination coverage was lowest in Bavaria with 85% in 2008. From March to mid-April 2008, four neighbouring Bavarian counties reported 55 measles-cases mostly linked to an ongoing measles outbreak in an anthroposophic school in Austria. We investigated this outbreak to guide future public health action.

METHODS

We applied the German national case-definition for measles and collected data using the national surveillance system and a questionnaire. Measles cases with disease onset a maximum of 18 days apart and spatial contact (e.g. same household, same school) were summed up in clusters. Two different interventions, which were implemented in schools and kindergartens in Bavaria, were compared by their impact on the size and duration of measles clusters. Susceptible persons were excluded from schools or kindergartens either with the first (intervention A) or second (intervention B) measles case occurring in the respective institution.

RESULTS

Among the 217 Bavarian measles cases identified from March-July 2008, 28 (13%) cases were attendees of the anthroposophic school in Austria. In total, vaccination status was known in 161 (74%) cases and 156 (97%) of them were not vaccinated. The main factor for non-vaccination was "fear of vaccine-related adverse events" (33%). Twenty-nine (18%) of 161 cases suffered complications. Exclusively genotype D5 was detected. Overall, 184 cases could be epidemiologically grouped into 59 clusters. Of those, 41 clusters could be linked to households and 13 to schools or kindergartens. The effect of intervention A and B was analysed in 10 school or kindergarten clusters. Depending on the respective intervention A or B, the median number of cases per cluster was 3 versus 13 (p = 0.05), and the median duration of a cluster was 3 versus 26 days (p = 0.13).

CONCLUSIONS

Introduction of measles virus into a pocket of susceptible persons (e.g. vaccination opponents or sceptics) may lead to large outbreaks in the general population, if the general population's vaccination coverage is below the WHO recommended level. Education on the safety of measles vaccine needs to be strengthened to increase measles vaccination coverage. Early intervention may limit spread in schools or kindergartens. Suspected measles has to be reported immediately to the local health authorities in order to allow intervention as early as possible.

Revealing new measles virus transmission routes by use of sequence analysis of phosphoprotein and hemagglutinin genes

With improved measles virus (MV) control, the genetic variability of the MV-nucleoprotein hypervariable region (NP-HVR) decreases. Thus, it becomes increasingly difficult to determine the origin of a virus using only this part of the genome. During outbreaks in Europe and Africa, we found MV strains with identical NP-HVR sequences. However, these strains showed considerable diversity within a larger sequencing window based on concatenated MV phosphoprotein and hemagglutinin genes (P/H pseudogenes). In Belarus, Germany, Russia, and the Democratic Republic of Congo, the P/H pseudogenes provided insights into chains of transmission, whereas identical NP-HVR provided none. In Russia, for instance, the P/H pseudogene identified temporal clusters rather than geographical clusters, demonstrating the circulation and importation of independent variants rather than large local outbreaks lasting for several years, as suggested by NP-HVR. Thus, by extending the sequencing window for molecular epidemiology, a more refined picture of MV circulation was obtained with more clearly defined links between outbreaks and transmission chains. Our results also suggested that in contrast to the P gene, the H gene acquired fixed substitutions that continued to be found in subsequent outbreaks, possibly with consequences for its antigenicity. Thus, a longer sequencing window has true benefits both for the epidemiological surveillance of measles and for the better monitoring of viral evolution.