Measles in Europe: an epidemiological assessment

Subacute myoclonic measles encephalitis - An opportunistic HIV-associated infection

Introduction

An unusual cluster of myoclonic epilepsy was observed in a Romanian pediatric HIV cohort concurrent with measles outbreaks. We describe this particular form of subacute measles encephalitis (SME) in a group of HIV-infected children and adolescents with severe immunosuppression.

Methods

This is a single-center study, starting in 1997 and covering 4 measles outbreaks in Romania. The presumptive diagnosis of subacute myoclonic measles encephalitis (SMME) was based on: (1) epidemiological data, previous measles episode or presumed contact with measles virus (MV), (2) clinical presentation with initial localized myoclonic jerks with rapid extension and subsequent motor deficit with preserved mental status, and (3) neuroimaging studies revealing cortical gray matter lesions. Definitive diagnosis was based on a neuropathological exam and immunohistochemistry of brain tissues, and measles RNA detection in the cerebrospinal fluid (CSF).

Results

Thirty-six patients were diagnosed with a particular form of SME during consecutive measles outbreaks in Romania: 1996-1998 (22); 2005-2008 (12); 2010-2011 (1) and 2016-2018 (1). Most children were born in the late 80s and had parenterally acquired HIV infection in early childhood. Before the episode of SMME, 11 patients had confirmed measles, while the rest, without typical rash, had a respiratory tract infection and/or presumed previous measles contact. In all patients, the clinical onset was sudden, with unilateral myoclonus. MRI findings revealed mainly focal cortical gray matter lesions. Neurologic symptoms progressed rapidly to coma and death in most patients. Three patients survived SMME, they had higher CD4 count at onset, slower progression of neurological symptoms, and benefit of immune recovery with cART. Immunocytochemistry studies revealed MV in the brain with a pattern suggesting an ascending viral neural infection. MV was isolated from CSF in 7 out of 8 patients. Sequence analysis of MV RNA from both nasopharyngeal swabs and CSF was available for one patient with similar N-450 strain characteristics.

Conclusion

During an outbreak of measles, neurological manifestations, especially myoclonus in immunosuppressed patients, can be related to measles even in the absence of an acute episode. This particular form of subacute myoclonic measles encephalitis is an opportunistic fatal disease. Immune recovery due to effective antiretroviral treatment might increase survival.

Importance of Population Education in Implementation of Compulsory Immunization Against Polyomyelitis in Children

Poliomyelitis is a contagious disease characterized by the appearance of fever, malaise, scratching in the throat, gastrointestinal signs, and after a few days the appearance of muscle paralysis, as well as respiratory and vasomotor disorders. Today, this disease is very rare, due to systemic active immunization. The aim of this study was to assess the level of knowledge and attitudes toward poliomyelitis and importance of immunization against it.

A specially designed survey questionnaire was used for interviewing purposes. Data analysis and processing were performed using a statistical data processing package (SPSS for Windows, version 20). A chi-square test was used from the statistical tests.

The educated profile of the respondents was as follows: medical sciences - 37 (50%), natural sciences and mathematics - 6 (8,1%), social sciences - 5 (6,8%), technical sciences - 19 (25,7%) and arts - 7 (9,5%). The study findings indicate a high level of awareness and knowledge of the population regarding polio, as well as good health awareness of the population about immunization i.e. polio vaccination. 34 respondents from the field of medical education answered the question exactly how the vaccine protects against the disease. In the field of natural mathematical sciences, a total of 3 gave the correct answer, which makes 50% of the total number of persons (6) in the mentioned field. In addition, majority of the study sample (70,3%) is aware that child should be vaccinated. Furthermore, 91,9% of respondents agree that education of parents regarding children vaccination is of great importance for whole community.

Based on findings of present study it can be concluded that efforts still need to be made in education of the wider population toward polio and the importance of vaccination. In addition to healthcare professionals, the entire community should participate in this strategic task.

A Historical Review of Military Medical Strategies for Fighting Infectious Diseases: From Battlefields to Global Health

The environmental conditions generated by war and characterized by poverty, undernutrition, stress, difficult access to safe water and food as well as lack of environmental and personal hygiene favor the spread of many infectious diseases. Epidemic typhus, plague, malaria, cholera, typhoid fever, hepatitis, tetanus, and smallpox have nearly constantly accompanied wars, frequently deeply conditioning the outcome of battles/wars more than weapons and military strategy. At the end of the nineteenth century, with the birth of bacteriology, military medical researchers in Germany, the United Kingdom, and France were active in discovering the etiological agents of some diseases and in developing preventive vaccines. Emil von Behring, Ronald Ross and Charles Laveran, who were or served as military physicians, won the first, the second, and the seventh Nobel Prize for Physiology or Medicine for discovering passive anti-diphtheria/tetanus immunotherapy and for identifying mosquito Anopheline as a malaria vector and plasmodium as its etiological agent, respectively. Meanwhile, Major Walter Reed in the United States of America discovered the mosquito vector of yellow fever, thus paving the way for its prevention by vector control. In this work, the military relevance of some vaccine-preventable and non-vaccine-preventable infectious diseases, as well as of biological weapons, and the military contributions to their control will be described. Currently, the civil-military medical collaboration is getting closer and becoming interdependent, from research and development for the prevention of infectious diseases to disasters and emergencies management, as recently demonstrated in Ebola and Zika outbreaks and the COVID-19 pandemic, even with the high biocontainment aeromedical evacuation, in a sort of global health diplomacy.

Epidemiology of skin diseases in Germany: systematic review of the current state of research - part 3: infectious skin diseases

The aim of this work was to systematically collect all previously published population-based epidemiological data on skin diseases in Germany. A systematic literature search was performed using PubMed/MEDLINE for the period of the last 15 years. With the aim to include all dermatological diseases, a diagnostic list based on the ICD-11 catalogue was compiled. This list included 1,347 skin diseases and formed the basis for the search. The present part 3 of the publication series deals with infectious skin diseases. The results on cutaneous tumor diseases (part 1) and non-infectious skin diseases (part 2) form the other parts of this publication series. The literature search yielded 4,605 hits, of which 72 papers on 43 different skin diseases were included in the synthesis. Among them were twelve hits on infectious dermatoses, of which six papers were related to measles. The highest lifetime prevalence rates were found for varicella and verrucae vulgaris. This work is the first systematic literature review that aimed to report all available epidemiological data on skin diseases in Germany. It was found that representative data on many infectious diseases are not yet available. Among the included studies, a high heterogeneity was found with regard to the methodology. Nevertheless, these epidemiological data have a wide range of uses and can serve as a reference for various epidemiological questions.

Dual RNA-Seq Enables Full-Genome Assembly of Measles Virus and Characterization of Host-Pathogen Interactions

Measles virus (MeV) has a negative-sense 15 kb long RNA genome, which is generally conserved. Recent advances in high-throughput sequencing (HTS) and Dual RNA-seq allow the analysis of viral RNA genomes and the discovery of viral infection biomarkers, via the simultaneous characterization of the host transcriptome. However, these host–pathogen interactions remain largely unexplored in MeV infections. We performed untargeted Dual RNA-seq in 6 pharyngeal and 6 peripheral blood mononuclear cell (PBMCs) specimens from patients with MeV infection, as confirmed via routine real-time PCR testing. Following optimised DNase treatment of total nucleic acids, we used the pharyngeal samples to build poly-A-enriched NGS libraries. We reconstructed the viral genomes using the pharyngeal datasets and we further conducted differential expression, gene-ontology and pathways enrichment analysis to compare both the pharyngeal and the peripheral blood transcriptomes of the MeV-infected patients vs. control groups of healthy individuals. We obtained 6 MeV genotype-B3 full-genome sequences. We minutely analyzed the transcriptome of the MeV-infected pharyngeal epithelium, detecting all known viral infection biomarkers, but also revealing a functional cluster of local antiviral and inflammatory immune responses, which differ substantially from those observed in the PBMCs transcriptome. The application of Dual RNA-seq technologies in MeV-infected patients can potentially provide valuable information on the virus genome structure and the cellular innate immune responses and drive the discovery of new targets for antiviral therapy.

Pandemics: past, present, future: That is like choosing between cholera and plague

The major epidemic and pandemic diseases that have bothered humans since the Neolithic Age and Bronze Age are surveyed. Many of these pandemics are zoonotic infections, and the mathematical modeling of such infections is illustrated. Plague, cholera, syphilis, influenza, SARS, MERS, COVID‐19, and new potential epidemic and pandemic infections and their consequences are described and the background for the spread of acute and chronic infections and the transition to endemic infections is discussed. The way we can prevent and fight pandemics is illustrated from the old and new well‐known pandemics. Surprisingly, the political reactions through different periods have not changed much during the centuries.

Humoral Immunity against Measles in Mother-Infant Pairs during the First Year of Life in Greece: A Cross-Sectional Study

Measles outbreaks have surfaced in Europe during the last decades. Infants <12 months of age were the most severely affected pediatric population. The aim of this study was to investigate the duration of maternally derived measles antibodies in infants aged 1 to 12 months in relation to maternal humoral immune status and other parameters. In a prospective, cross-sectional cohort study, 124 mother/infant pairs and 63 additional infants were recruited from October 2015 through December 2019. Infants were hospitalized in a university pediatric department of a general hospital. Demographic and epidemiological data were recorded and blood samples were collected from mothers and their infants. Commercially available enzyme-linked immunosorbent assay (ELISA) was used for measuring measles antibodies. Fifty nine percent of mothers had vaccine-induced and 15% infection-acquired measles immunity. Eighty-eight percent and 94% of infants were unprotected by 5 and 10 months of age, respectively. Maternal antibody levels and infant age were significant independent predictors of infants’ antibody levels whereas the method of maternal immunity acquisition, age, and origin [Greek/non-Greek] were not. Our findings suggest that about 90% of infants are susceptible to measles beyond the age of 4 months. To our knowledge, these are the first data from Greece reported under the current community composition and epidemiological conditions.

Oscillatory dynamics in the dilemma of social distancing

Social distancing as one of the main non-pharmaceutical interventions can help slow down the spread of diseases, like in the COVID-19 pandemic. Effective social distancing, unless enforced as drastic lockdowns and mandatory cordon sanitaire, requires consistent strict collective adherence. However, it remains unknown what the determinants for the resultant compliance of social distancing and their impact on disease mitigation are. Here, we incorporate into the epidemiological process with an evolutionary game theory model that governs the evolution of social distancing behaviour. In our model, we assume an individual acts in their best interest and their decisions are driven by adaptive social learning of the real-time risk of infection in comparison with the cost of social distancing. We find interesting oscillatory dynamics of social distancing accompanied with waves of infection. Moreover, the oscillatory dynamics are dampened with a non-trivial dependence on model parameters governing decision-makings and gradually cease when the cumulative infections exceed the herd immunity. Compared to the scenario without social distancing, we quantify the degree to which social distancing mitigates the epidemic and its dependence on individuals’ responsiveness and rationality in their behaviour changes. Our work offers new insights into leveraging human behaviour in support of pandemic response.

Pediatric measles cases by residence status in Tel Aviv, Israel

BACKGROUND

Measles is a vaccine-preventable infectious disease whose outbreaks generally originate from exposure to populations with low vaccination coverage.

METHODS

This study compared the rates and morbidity of measles cases in the district of Tel-Aviv during two outbreaks (2012 and 2018-2019) by citizenship and geographic location.

RESULTS

There were 67 pediatric cases reported in 2012 and 222 in 2018-2019. Cases were more likely to have pneumonia in 2012 as compared to in 2018-2019 (58.2% versus 6.3%) and less likely to report a single vaccination dose (9.5% versus 22.8%, respectively). In 2012, the majority of cases were among children without legal residence (CWLR), while in 2018-2019, they were the minority of cases (N = 54, 80.6% versus N = 51, 23.0%, respectively). In both outbreaks, CWLR were more likely to be less than one year old (the recommended age for the first dose of measles vaccination), unvaccinated or with unknown vaccine status, to be treated in a tertiary care center, and to have pneumonia than children with Israeli citizenship (CC). In both outbreaks, CWLR lived in a concentrated neighborhood in Southern Tel Aviv.

CONCLUSION

While the two measles outbreaks differed in overall morbidity, in both outbreaks CWLR presented with a more severe clinical presentation and were less likely to be vaccinated (in part due to their younger age) than CC. The geographically concentration of CWLR was distinct from that of the CC in both outbreaks. Healthcare professionals should promote vaccination uptake and increase parents' awareness to early signs of the disease.

Early Measles Vaccination During an Outbreak in the Netherlands: Short-Term and Long-Term Decreases in Antibody Responses Among Children Vaccinated Before 12 Months of Age

Background

The majority of infants will not be protected by maternal antibodies until their first measles vaccination, between 12 and 15 months of age. This provides incentive to reduce the age at measles vaccination, but immunological consequences are insufficiently understood, and long-term effects are largely unknown.

Methods

A total of 79 infants who received early measles vaccination between 6 and 12 months age and a second dose at 14 months of age were compared to 44 children in a control group who received 1 dose at 14 months of age. Measles virus–specific neutralizing antibody concentrations and avidity were determined up to 4 years of age.

Results

Infants who first received measles vaccination before 12 months of age had a long-term decrease in the concentration and avidity of measles virus–specific neutralizing antibodies, compared with infants in the control group. For 11.1% of children with a first dose before 9 months of age, antibody levels at 4 years of age had dropped below the cutoff for clinical protection.

Conclusions

Early measles vaccination provides immediate protection in the majority of infants but yields a long-term decrease in neutralizing antibody responses, compared to vaccination at a later age. Additional vaccination at 14 months of age does not improve this. Over the long term, this may result in an increasing number of children susceptible to measles.

Immunogenicity and Safety of an Early Measles Vaccination Schedule at 6 and 12 Months of Age in Human Immunodeficiency Virus (HIV)-Unexposed and HIV-Exposed, Uninfected South African Children

BACKGROUND

Measles morbidity and mortality rates are greatest in children <12 months old, with increased susceptibility in human immunodeficiency virus (HIV)-exposed children. We evaluated the immunogenicity and safety of an early 2-dose measles vaccine regimen administered at 6 and 12 months of age in South Africa.

METHODS

HIV-unexposed (HU) (n = 212) and HIV-exposed, uninfected (HEU) (n = 71) children received measles vaccination (CAM-70) at 6 and 12 months of age. Measles immunoglobulin G titers were measured by means of enzyme-linked immunosorbent assay before and 1 month after each vaccine dose.

RESULTS

The majority of children (88.2% HU and 95.8% HEU; P = .04) were seronegative (<150 mIU/mL) to measles at 4.2 months of age. This was particularly evident among infants of mothers born from 1992 onwards (year of public nationwide measles vaccine availability). One month after the first measles vaccine, 42.3% of HU and 46.4% of HEU children were seropositive (≥330 mIU/mL). After the second dose, the proportion seropositive increased to 99.0% in HU and 95.3% in HEU children. Safety profiles were similar between HU and HEU children.

CONCLUSIONS

Early 2-dose measles vaccination at 6 and 12 months of age was safe and induced antibody responses in HU and HEU children, which could partly offset the early loss of maternally derived antibodies in infants born to predominantly measles-vaccinated mothers.

CLINICAL TRIALS REGISTRATION

NCT03330171.

Are the Objectives Proposed by the WHO for Routine Measles Vaccination Coverage and Population Measles Immunity Sufficient to Achieve Measles Elimination from Europe?

Background: The World Health Organization (WHO) proposed two-dose measles vaccination coverage of at least 95% of the population and percentages of measles immunity in the population of 85%−95% in order to achieve measles elimination in Europe. The objectives of this study were: (1) to determine the measles vaccination coverage required to establish herd immunity against measles viruses with basic reproduction numbers (Ro) ranging from 6 to 60, and (2) to assess whether the objectives proposed by the WHO are sufficient to establish herd immunity against measles viruses. Methods: The herd immunity effects of the recommended objectives were assessed by considering the prevalence of protected individuals required to establish herd immunity against measles viruses with Ro values ranging from 6 to 60. Results: The study found that percentages of two-dose measles vaccination coverage from 88% to 100% could establish herd immunity against measles viruses with Ro from 6 to 19, assuming 95% measles vaccination effectiveness. The study found that the objective of 95% for two-dose measles vaccination coverage proposed by the WHO would not be sufficient to establish herd immunity against measles viruses with Ro ≥ 10, assuming 95% measles vaccination effectiveness. By contrast, a 97% measles vaccination coverage objective was sufficient to establish herd immunity against measles viruses, with Ro values from 6 to 13. Measles immunity levels recommended in individuals aged 1−4 years (≥85%) and 5−9 years (≥90%) might not be sufficient to establish herd immunity against most measles viruses, while those recommended in individuals aged 10 or more years (≥95%) could be sufficient to establish herd immunity against measles viruses with Ro values from 6 to 20. Conclusion: To meet the goal of measles elimination in Europe, it is necessary to achieve percentages of two-dose measles vaccination coverage of at least 97%, and measles immunity levels in children aged 1−9 years of at least 95%.

High number of hospitalisations and non-classical presentations: lessons learned from a measles outbreak in 2017, Belgium

We describe and analyse an outbreak of measles that affected Belgium early 2017. In total, 289 cases were reported, mostly (53%) in people 15 years or older. For 133 (46%) vaccination status was unknown and a further 117 (41%) were not vaccinated. According to national guidelines, 83 of the unvaccinated cases (29% of total cases) should have received minimum one dose of vaccine, but did not. One in five cases (21%) did not present with the classical triad of fever, rash and any of coryza, conjunctivitis or cough. Rash was the most sensitive symptom, being absent in only six cases. A large proportion of cases (125/289, 43%) required hospitalisation. In hospitalised patients, the most commonly observed complications were hepatic disorders (present in 58/125 hospitalised patients, 46%). Thirty-six of the cases (12%) were in healthcare workers and nosocomial spread contributed importantly to the outbreak. Older age at presentation, altered clinical presentations and presence of complications like hepatitis can delay the correct diagnosis of measles. Clinicians should maintain a high index of suspicion in any individual presenting with rash. If the elimination target is to be reached, catch-up vaccination campaigns should be intensified and target young adults and health care workers.

Seroprevalence of Transplacentally acquired Measles antibodies in unvaccinated infants at nine months of age and its relation to the feeding practices

BACKGROUND

In recent years Pakistan has faced frequent measles outbreaks killing hundreds of children despite the availability of vaccine for decades. This study was undertaken to determine the persistence of maternal transferred measles antibody levels in infants before measles vaccination with relation to their feeding practices.

METHODS

A cross sectional study was conducted at district Islamabad over 1 year between 1st October 2013 to 30th Sept. 2016. Any infant less than 9 months of age, not suffering from an acute or debilitating illness and not vaccinated was enrolled in the study. After taking written informed consent from parents / guardians, information was collected on a pretested questionnaire. About 3 cc venous blood was taken to quantify any measles IgG antibodies. Data was analyzed by using Epi Info 7.2 version.

RESULTS

Three hundred eighty-four infants were enrolled and were divided into three age groups, 1-90, 91-180 and 181-270 days age groups. Mean age of infants was 4.4 months ±3.2 SD. Male to female ratio was 1.2:1. A level of maternal measles IgG antibodies ≥12 U/ml was taken as protective. Of total 384 infants, 91(24%) had protective measles antibody titters (> 12 U/ml). and 65 (73%) of them were on breast milk. Highest antibody levels were found in 1-90 days age group. Analysis showed that 181-270 days aged infants had 3.1875 more odds of having unprotected/ low levels of antibodies against measles than children aged less than 180 days. Age group < 180 days found to be statistically significant with protective IgG levels (OR: 3.1875, P value: < 0.000063).

CONCLUSION

Measles protective antibodies were found in infants < 180 days age group. Breast feeding provides early protection against measles. Levels drop down to low levels immediately after birth and then after 06 months. It is, therefore, recommended that measles vaccination should be considered for administration at 6 months or even earlier if measles immunity is desired.

Relationship Between Media Coverage and Measles-Mumps-Rubella (MMR) Vaccination Uptake in Denmark: Retrospective Study

BACKGROUND

Understanding the influence of media coverage upon vaccination activity is valuable when designing outreach campaigns to increase vaccination uptake.

OBJECTIVE

To study the relationship between media coverage and vaccination activity of the measles-mumps-rubella (MMR) vaccine in Denmark.

METHODS

We retrieved data on media coverage (1622 articles), vaccination activity (2 million individual registrations), and incidence of measles for the period 1997-2014. All 1622 news media articles were annotated as being provaccination, antivaccination, or neutral. Seasonal and serial dependencies were removed from the data, after which cross-correlations were analyzed to determine the relationship between the different signals.

RESULTS

Most (65%) of the anti-vaccination media coverage was observed in the period 1997-2004, immediately before and following the 1998 publication of the falsely claimed link between autism and the MMR vaccine. There was a statistically significant positive correlation between the first MMR vaccine (targeting children aged 15 months) and provaccination media coverage (r=.49, P=.004) in the period 1998-2004. In this period the first MMR vaccine and neutral media coverage also correlated (r=.45, P=.003). However, looking at the whole period, 1997-2014, we found no significant correlations between vaccination activity and media coverage.

CONCLUSIONS

Following the falsely claimed link between autism and the MMR vaccine, provaccination and neutral media coverage correlated with vaccination activity. This correlation was only observed during a period of controversy which indicates that the population is more susceptible to media influence when presented with diverging opinions. Additionally, our findings suggest that the influence of media is stronger on parents when they are deciding on the first vaccine of their children, than on the subsequent vaccine because correlations were only found for the first MMR vaccine.

Measles Vaccine

Measles remains an important cause of child morbidity and mortality worldwide despite the availability of a safe and efficacious vaccine. The current measles virus (MeV) vaccine was developed empirically by attenuation of wild-type (WT) MeV by in vitro passage in human and chicken cells and licensed in 1963. Additional passages led to further attenuation and the successful vaccine strains in widespread use today. Attenuation is associated with decreased replication in lymphoid tissue, but the molecular basis for this restriction has not been identified. The immune response is age dependent, inhibited by maternal antibody (Ab) and involves induction of both Ab and T cell responses that resemble the responses to WT MeV infection, but are lower in magnitude. Protective immunity is correlated with levels of neutralizing Ab, but the actual immunologic determinants of protection are not known. Because measles is highly transmissible, control requires high levels of population immunity. Delivery of the two doses of vaccine needed to achieve >90% immunity is accomplished by routine immunization of infants at 9-15 months of age followed by a second dose delivered before school entry or by periodic mass vaccination campaigns. Because delivery by injection creates hurdles to sustained high coverage, there are efforts to deliver MeV vaccine by inhalation. In addition, the safety record for the vaccine combined with advances in reverse genetics for negative strand viruses has expanded proposed uses for recombinant versions of measles vaccine as vectors for immunization against other infections and as oncolytic agents for a variety of tumors.

Les vaccins dans la prévention des infections associées aux soins

Les infections associées aux soins (IAS) constituent un véritable problème de santé publique. Escherichia coli, Staphylococcus aureus, Clostridium difficile sont les plus souvent à l’origine des IAS. L’antibiorésistance fréquente complique encore la prise en charge et des impasses thérapeutiques existent à présent. Les mesures d’hygiène hospitalière bien qu’essentielles sont insuffisantes pour diminuer drastiquement les IAS. Ainsi, des stratégies alternatives à l’antibiothérapie s’avèrent nécessaires pour prévenir et traiter les IAS. Parmi celles-ci, la vaccination et l’immunisation passive sont probablement les plus prometteuses. Nous avons fait une mise au point sur les vaccins disponibles et en développement clinique pour lutter contre les IAS, chez les patients à risque d’IAS et les soignants. L’intérêt de la vaccination grippale et rotavirus chez les patients pour prévenir ces IAS virales a été examiné. Le développement d’un vaccin anti-S. aureus, déjà émaillé de 2 échecs est complexe. Toutefois, ces échecs ont permis d’améliorer les connaissances sur l’immunité anti-S. aureus. La mise à disposition d’un vaccin préventif anti-C. difficile semble plus proche. Pour les autres bactéries gram négatif responsables d’IAS, le développement est moins avancé. La vaccination des patients à risques d’IAS pose également des problèmes de réponse vaccinale qu’il faudra résoudre pour utiliser cette stratégie. Ainsi, la vaccination des soignants, de par l’effet de groupe permet également de prévenir les IAS. Nous faisons ici le point sur l’intérêt de la vaccination des soignants contre la rougeole, la coqueluche, la grippe, la varicelle, l’hépatite B pour réduire les IAS avec des vaccins déjà disponibles.

A report of outbreaks of measles on the southern coast of Iran from 2009 to 2015

Introduction

Immunogenicity assessment figures of the measles vaccine is approximately 90%, and decreases over time. Therefore, the immunity level of measles vaccine is variable which can result in outbreaks of measles in a population. The aim of current study was to report the outbreaks of measles in Hormozgan province from 2009 to 2015.

Methods

This cross-sectional study was carried out in Hormozgan Province on the southern coast of Iran. The documented data of all cases suspected of measles are included in this study. We used a checklist including gender, age, area, place of residence, contact history, and vaccination status to extract required data. Data was analyzed using IBM SPSS statistics software version 21.0.

Results

Eight hundred fifty-one suspicious cases of measles were determined from 2006 to 2015. Of those, 135 infected cases were reported. Among patients, 49% were male, 79% were Iranian, 18% were Afghans, and 3 % were Indians or Pakistanis. Also, 31% of cases were reported from Bandar Abbas, 25% were reported from Minab, 18% from Qeshm, 17 % from Jask and other cases were reported from other areas of the Hormozgan Province. Thirty percent of the cases were reported from urban areas.

Conclusion

A high percentage of cases with measles in rural areas were reported in the areas which were covered by complete vaccination. This shows interruption of cold continuum. Also, increasing the number of under one-years-old cases reported, could be due to poor nutritional status of the children and insufficient immunization of mothers. Further studies are required for identifying the causes of cold continuum interruption. Further studies are required for the assessment of immunization in children and mothers and various vaccination protocols.

The Immune Response in Measles: Virus Control, Clearance and Protective Immunity

Measles is an acute systemic viral infection with immune system interactions that play essential roles in multiple stages of infection and disease. Measles virus (MeV) infection does not induce type 1 interferons, but leads to production of cytokines and chemokines associated with nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) signaling and activation of the NACHT, LRR and PYD domains-containing protein (NLRP3) inflammasome. This restricted response allows extensive virus replication and spread during a clinically silent latent period of 10–14 days. The first appearance of the disease is a 2–3 day prodrome of fever, runny nose, cough, and conjunctivitis that is followed by a characteristic maculopapular rash that spreads from the face and trunk to the extremities. The rash is a manifestation of the MeV-specific type 1 CD4⁺ and CD8⁺ T cell adaptive immune response with lymphocyte infiltration into tissue sites of MeV replication and coincides with clearance of infectious virus. However, clearance of viral RNA from blood and tissues occurs over weeks to months after resolution of the rash and is associated with a period of immunosuppression. However, during viral RNA clearance, MeV-specific antibody also matures in type and avidity and T cell functions evolve from type 1 to type 2 and 17 responses that promote B cell development. Recovery is associated with sustained levels of neutralizing antibody and life-long protective immunity.

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.

Parental attitudes towards measles vaccination in the canton of Aargau, Switzerland: a latent class analysis

BACKGROUND

Despite the successes of routine national childhood vaccination programmes, measles remains a public health concern. The purpose of this paper is to investigate how patterns of parental attitudes are linked to the decision-making process for or against MMR vaccination. This exploratory study was designed to identify distinct patterns of attitudes towards or against measles vaccination through Latent Class Analysis (LCA) in a sub-sample of mothers living in the canton of Aargau in Switzerland.

METHODS

Parents of young children below 36 months of age were randomly selected through parents' counsellors' registries. Among other questions, respondents were asked to state their agreement in response to 14 belief statements regarding measles vaccination on a 5-point Likert scale. To identify groups of parents showing distinct patterns of attitudes and beliefs regarding measles vaccination, we used Latent Class Analysis (LCA).

RESULTS

The LCA showed three classes of parents with different attitudes and believes towards measles vaccination: The biggest group (class 1) are those having positive attitudes towards immunisation, followed by the second biggest group (class 2) which is characterised by having fearful attitudes and by showing uncertainty about immunisation. The third group (class 3) shows distinct patterns of critical attitudes against immunisation. Within this group over 90 % agree or totally agree that immunisation is an artificial intrusion into the natural immune system and therefore want to vaccinate their children only if necessary.

CONCLUSION

We find that parents in the Canton Aargau who hesitate to vaccinate their children against measles, mumps and rubella show distinct opinions and attitudes. Health professionals should be aware of these perceptions to tailor their messages accordingly and positively influence these parents to vaccinate their children. Special attention needs to be given to those parents who are planning to vaccinate their children but are not following the national guidelines.

Constraints on the Genetic and Antigenic Variability of Measles Virus

Antigenic drift and genetic variation are significantly constrained in measles virus (MeV). Genetic stability of MeV is exceptionally high, both in the lab and in the field, and few regions of the genome allow for rapid genetic change. The regions of the genome that are more tolerant of mutations (i.e., the untranslated regions and certain domains within the N, C, V, P, and M proteins) indicate genetic plasticity or structural flexibility in the encoded proteins. Our analysis reveals that strong constraints in the envelope proteins (F and H) allow for a single serotype despite known antigenic differences among its 24 genotypes. This review describes some of the many variables that limit the evolutionary rate of MeV. The high genomic stability of MeV appears to be a shared property of the Paramyxovirinae, suggesting a common mechanism that biologically restricts the rate of mutation.

Factors associated with delayed measles vaccination among children in Shenzhen, China: a case-control study

A delay in the first dose of measles-containing vaccine (MCV1) may contribute to outbreaks of measles, resulting in a high age-specific incidence in infants<1 y of age. To determine the factors associated with delayed MCV1 vaccinations, we used data from the China Information Management System for Immunization Programming. Additionally, the parents/guardians of 430 children whose MCV1 vaccinations were delayed, as well as the parents/guardians of 424 children who received timely vaccinations, were surveyed by telephone. Children were less likely to receive timely MCV1 vaccinations if they belonged to an immigrant group, were male, had poor health status, had a father whose occupation e.g., a manager, had a history of delays in other Expanded Programs on Immunization (EPI) vaccinations, had parents who did not believe vaccinations were important for their children, and experienced shorter travel times to and longer waiting times in EPI clinics. The children of mothers whose occupational status (technician) were more likely to receive timely MCV1 vaccinations. The timeliness of MCV1 vaccinations should be considered as an additional indicator of the quality of vaccination programs.

Prevalence of measles virus-specific IgG antibodies according to vaccination schedule in medical students of Padua University

Aims: The goal of the present study was to establish the efficacy of the measles vaccine and the validity of the vaccination schedule adopted in Italy. Materials & methods: The following procedures are adopted: analyze the compliance to the vaccination schedule; assess the seroprevalence of measles antibodies according to the year of birth and the number of doses; and investigate the persistence of positive antibodies post-vaccination. We gathered and elaborated data of both vaccination history and seroprevalence against measles in a large population of students (4195) belonging to the Medical School of Padua University (Italy). Results: Our results reveal a requirement for a two-dose vaccination schedule to ensure protection from the disease. Nevertheless, these results clearly indicate that the percentage of seropositivity reached using the two-dose strategy is below the percentage (95%) that ensures optimal population immunity. Conclusion: It is uncertain whether immune coverage persists when circulating antibodies vanish, but two vaccine doses should prevent disease outbreaks.

Malaria vaccines: looking back and lessons learnt

The current status of malaria vaccine approaches has the background of a long and arduous path of malaria disease control and vaccine development. Here, we critically review with regard to unilateral interventional approaches and highlight the impact of socioeconomic elements of malaria endemicity. The necessity of re-energizing basic research of malaria life-cycle and Plasmodium developmental biology to provide the basis for promising and cost-effective vaccine approaches and to reach eradication goals is more urgent than previously believed. We closely analyse the flaws of various vaccine approaches, outline future directions and challenges that still face us and conclude that the focus of the field must be shifted to the basic research efforts including findings on the skin stage of infection. We also reflect on economic factors of vaccine development and the impact of public perception when it comes to vaccine uptake.

Prevalence of anti-rubella, anti-measles and anti-mumps IgG antibodies in neonates and pregnant women in Catalonia (Spain) in 2013: susceptibility to measles increased from 2003 to 2013

Non-immune neonates and non-immune pregnant women are at risk of developing rubella, measles and mumps infections, including congenital rubella syndrome. We describe the seroepidemiology of measles, mumps and rubella (MMR) in neonates and pregnant women in Catalonia (Spain). Anti-rubella, anti-measles and anti-mumps serum IgG titres were assessed using enzyme-linked immunosorbent assay (ELISA) tests in 353 cord blood samples from neonates of a representative sample of pregnant women obtained in 2013. The prevalence of protective antibody titres in neonates was 96 % for rubella IgG (≥8 IU/ml), 90 % for measles IgG (>300 IU/ml) and 84 % for mumps IgG (>460 EU/ml). Slightly lower prevalences of protective IgG titres, as estimated from the cord blood titres, were found in pregnant women: 95 % for rubella IgG, 89 % for measles IgG and 81 % for mumps IgG. The anti-measles and anti-mumps IgG titres and the prevalences of protective IgG titres against measles and mumps increased significantly (p < 0.001) with maternal age. The prevalence of protective anti-measles IgG titres decreased by 7 % [odds ratio (OR) = 0.15, p < 0.001), the prevalence of protective anti-rubella IgG titres increased by 3 % (OR = 1.80, p < 0.05) and the MMR vaccination coverage (during childhood) in pregnant women increased by 54 % (OR = 2.09, p < 0.001) from 2003 to 2013. We recommend to develop an MMR prevention programme in women of childbearing age based on mass MMR vaccination or MMR screening and vaccination of susceptible women to increase immunity levels against MMR.

Measles in Morocco: epidemiological profile and impact of vaccination strategy

INTRODUCTION

Measles continues to persist as one of the leading causes of infant mortality due to preventable diseases through vaccination. This study aims to highlight measles in Morocco, and to present the vaccination strategy implemented to control and eliminate the disease in this country.

METHODS

Throughout this study, and based on data from the Directorate of Epidemiology and Control of Diseases and those of the Directorate of Population, we present an overview on the epidemiological trends of measles from 1997 to 2012, while evoking the plans established by the Ministry of Health (MoH) for the control and elimination of this disease.

RESULTS

The number of measles cases has decreased in Morocco between 1997 and 2012 (2574-720 reported cases per year) as a result of four important steps: first, increasing the routine vaccination coverage (73-94%); second, the introduction of the second dose of the combined vaccine against measles and rubella in schools (children aged 6 years) since 2003; third, the first catch-up campaign of vaccination in Morocco in 2008, for which coverage was highly satisfactory (96% and 100% for age groups 5-59 months and 5-14 years, respectively); and fourth, the organization of a mass vaccination campaign in 2013 that targeted children from aged 9 months to 19 years.

CONCLUSION

The vaccination plan and the surveillance system executed in Morocco within the framework of the regional project implemented by the World Health Organization (WHO) to eliminate measles has given remarkable results regarding the reduction of measles cases and mortality due to this disease. According to the data from MoH and WHO, the number of reported and confirmed measles cases decreased drastically during 2014. However, these efforts are still unsatisfactory compared to the prospective of eliminating the disease by 2015.

International travel patterns and travel risks for stem cell transplant recipients

BACKGROUND

Stem cell transplantation (SCT) is being increasingly utilized for multiple medical illnesses. However, there is limited knowledge about international travel patterns and travel-related illnesses of stem cell transplant recipients (SCTRs).

METHODS

An observational cross-sectional study was conducted among 979 SCTRs at Memorial Sloan Kettering Cancer Center using a previously standardized and validated questionnaire. International travel post SCT, pre-travel health advice, exposure risks, and travel-related illnesses were queried.

RESULTS

A total of 516 SCTRs completed the survey (55% response rate); of these, 40% were allogeneic SCTRs. A total of 229 (44.3%) respondents reported international travel outside the United States and Canada post SCT. The international travel incidence was 32% [95% confidence interval CI 28-36] within 2 years after SCT. Using multivariable Cox regression analysis, variables significantly associated with international travel within first 2 years after SCT were history of international travel prior to SCT [hazard ratio (HR) = 5.3, 95% CI 2.3-12.0], autologous SCT (HR = 2.6, 95% CI 1.6-2.8), foreign birth (HR = 2.3, 95% CI 1.5-3.3), and high income (HR = 2.0, 95% CI 1.8-3.7). During their first trip, 64 travelers (28%) had traveled to destinations that may have required vaccination or malaria chemoprophylaxis. Only 56% reported seeking pre-travel health advice. Of those who traveled, 16 travelers (7%) became ill enough to require medical attention during their first trip after SCT. Ill travelers were more likely to have visited high-risk areas (60 vs 26%, p = 0.005), to have had a longer mean trip duration (24 vs 12 days, p = 0.0002), and to have visited friends and relatives (69 vs 21%, p < 0.0001).

CONCLUSIONS

International travel was common among SCTRs within 2 years after SCT and was mainly to low-risk destinations. Although the overall incidence of travel-related illnesses was low, certain subgroups of travelers were at a significantly higher risk. Pre-travel health counseling and interventions were suboptimal.

Cotreatment of congenital measles with vitamin a and intravenous immunoglobulin

Although the measles vaccine has been part of routine national childhood vaccination programs throughout Europe, measles remains a public health concern. High numbers of cases and outbreaks have occurred throughout the European continent since 2011, and an increasing number of cases have been reported in Turkey since 2012. During a recent measles outbreak in Turkey, 2 pregnant women contracted measles prior to delivering preterm infants at Hacettepe University Hospital. Measles virus genomic RNA and IgM antibodies against measles were detected in the cord blood of infants and mothers in both cases. The infants were treated with intravenous immunoglobulin (IVIG) and vitamin A. Transient thrombocytopenia was present in 1 infant and treated with an additional dose of IVIG and vitamin A. The infants were discharged, without complications, within 10 days of birth. The successful treatment of these cases suggests that infants who have been exposed to, or infected with, measles may benefit from cotreatment of vitamin A and IVIG.

Measles associated with international travel in the region of the Americas, Australia and Europe, 2001-2013: a systematic review

BACKGROUND

Travel volumes are still increasing resulting in a more interconnected world and fostering the spread of infectious diseases. We aimed to evaluate the relevance of travel-related measles, a highly transmissible and vaccine-preventable disease.

METHOD

Between 2001 and 2013, surveillance and travel-related measles data were systematically reviewed according to the PRISMA guidelines with extraction of relevant articles from Medline, Embase, GoogleScholar and from public health authorities in the Region of the Americas, Europe and Australia.

RESULTS

From a total of 960 records 44 articles were included and they comprised 2128 imported measles cases between 2001 and 2011. The proportion of imported cases in Europe was low at 1-2%, which reflects the situation in a measles-endemic region. In contrast, imported and import-related measles accounted for up to 100% of all cases in regions with interrupted endemic measles transmission. Eleven air-travel related reports described 132 measles index cases leading to 47 secondary cases. Secondary transmission was significantly more likely to occur if the index case was younger or when there were multiple infectious cases on board. Further spread to health care settings was found. Measles cases associated with cruise ship travel or mass gatherings were sporadically observed.

CONCLUSIONS

Within both, endemic and non-endemic home countries, pretravel health advice should assess MMR immunity routinely to avoid measles spread by nonimmune travelers. To identify measles spread as well as to increase and sustain high vaccination coverages joint efforts of public health specialists, health care practitioners and travel medicine providers are needed.

Progress towards measles elimination in Singapore

OBJECTIVE

We describe the epidemiological trends of measles in Singapore in relation to its progress towards measles elimination and identify gaps in fulfilling the World Health Organization Western Pacific Regional Office regional measles elimination criteria.

METHODS

Epidemiological data on measles maintained by the Communicable Diseases Division, Ministry of Health from 1981 to 2012 were collated and analysed. Data on measles vaccination coverage were obtained from the National Immunization Registry and School Health Services, Health Promotion Board. To assess the seroprevalence of the population, the findings of periodic seroepidemiological surveys on measles were traced and reviewed.

FINDINGS

With the successful implementation of the National Childhood Immunization Programme using the monovalent measles vaccine, measles incidence declined from 88.5 cases per 100,000 in 1984 to 6.9 per 100,000 in 1991. Resurgences were observed in 1992, 1993 and 1997. A 'catch-up' vaccination programme using the trivalent measles, mumps and rubella (MMR) vaccine was conducted in 1997, followed by introduction of the two-dose vaccination schedule in January 1998. Measles incidence subsequently declined sharply to 2.9 per 100,000 in 1998. Vaccination coverage was maintained at 95% for the first dose and 92-94% for the second dose. Seroprevalence surveys showed seropositivity for measles IgG antibodies in over 95% of adults in 2004, and in 83.1% of children aged 1-17 years in 2008-2010. Sporadic cases with occasional clusters of two or more cases continued to occur among the unvaccinated population, especially children aged below 4 years. The predominant measles virus genotype has shifted from D9 to the B3 and G3 genotypes, which are endemic in neighbouring countries.

CONCLUSION

Singapore has made good progress towards the elimination of endemic measles. To further eliminate sporadic cases of measles, the national immunisation schedule has recently been amended to vaccinate children with 2 doses of MMR vaccine before 2 years of age.

Lower transplacental antibody transport for measles, mumps, rubella and varicella zoster in very preterm infants

BACKGROUND

Maternal antibodies, transported over the placenta during pregnancy, contribute to the protection of infants from infectious diseases during the first months of life. In term infants, this protection does not last until the first recommended measles-mumps-rubella vaccination at 14 months in the Netherlands, while these viruses still circulate. The aim of the study was to investigate the antibody concentration against measles, mumps, rubella and varicella (MMRV) in mothers and preterm infants or healthy term infants at birth.

METHODS

Antibody concentrations specific for MMRV were measured in cord blood samples from preterm (gestational age <32 weeks and/or birth weight <1500 g) and term infants, and matched maternal serum samples, using a fluorescent bead-based multiplex immune-assay.

RESULTS

Due to lower placental transfer ratios of antibodies against MMRV in 96 preterm infants (range 0.75-0.87) compared to 42 term infants (range 1.39-1.65), the preterm infants showed 1.7-2.5 times lower geometric mean concentrations at birth compared to term infants. Maternal antibody concentration is the most important determinant of infant antibody concentration against MMRV.

CONCLUSIONS

Preterm infants benefit to a lesser extent from maternal antibodies against measles, mumps, rubella and varicella than term infants, posing them even earlier at risk for infectious diseases caused by these still circulating viruses.

Morbillivirus vaccines: recent successes and future hopes

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Morbilliviruses cause severe disease in both human and animal populations.

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Morbilliviruses are recognised targets for eradication.

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Live attenuated vaccines are available for some morbilliviruses.

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DIVA vaccines may be important for future morbillivirus eradication attempts.

The impact of morbilliviruses on both human and animal populations is well documented in the history of mankind. Indeed, prior to the development of vaccines for these diseases, morbilliviruses plagued both humans and their livestock that were heavily relied upon for food and motor power within communities. Measles virus (MeV) was responsible for the death of millions of people annually across the world and those fortunate enough to escape the disease often faced starvation where their livestock had died following infection with rinderpest virus (RPV) or peste des petits ruminants virus (PPRV). Canine distemper virus has affected dog populations for centuries and in the past few decades appears to have jumped species, now causing disease in a number of non-canid species, some of which are been pushed to the brink of extinction by the virus. During the age of vaccination, the introduction and successful application of vaccines against rinderpest and measles has led to the eradication of the former and the greater control of the latter. Vaccines against PPR and canine distemper have also been generated; however, the diseases still pose a threat to susceptible species. Here we review the currently available vaccines against these four morbilliviruses and discuss the prospects for the development of new generation vaccines.

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.

Knowledge and risk perception of measles and factors associated with vaccination decisions in subjects consulting university affiliated public hospitals in Lyon, France, after measles infection

In 2011, a large number of European countries faced measles outbreaks, France accounting for more than half of the reported cases. The Rhône-Alpes region, located in south-east France, was one of the most affected provinces, with an incidence rate of 97.9 cases per 100 000 inhabitants. We conducted a retrospective survey of adults and parents of children consulting university affiliated public hospitals because of measles infections between January 1, 2010 and September 2012 in Lyon, France. Our main objectives were to evaluate (1) the level of study population knowledge of measles, (2) vaccination practices, and (3) changes in opinion with regard to measles vaccination after disease onset. Overall, 73.64% of patients were not vaccinated or partially vaccinated. The main reason for non-vaccination in children was inappropriate age while among non-vaccinated adults, 29.3% could not give any reason. In total, 29.1% of the responding parents and 24.2% of adult cases were opposed to vaccination "in principle." A large number of patients did not recognize measles as a serious illness and were unaware of its complications. Among parents of infected children, knowledge of transmission mode (odds ratio [OR] = 5.9; 95% confidence interval [95% CI]: 1.64-21.26), perceived severity of measles (OR = 1.5; 95% CI: 1.06-2.13), and absence of hepatitis B vaccination (OR = 0.17; 95% CI: 0.04-0.65) were independently associated with a more positive opinion about measles vaccination after disease onset. In adult patients, low education level (OR = 3.39; 95% CI: 1.03-11.11) and lack of knowledge of sequelae (OR = 10.19; 95% CI: 1.14-91.31) were linked with a more positive opinion. Individuals affected by vaccine-preventable diseases are interesting populations to study disease impact on vaccine perception.

Deciphering the relative weights of demographic transition and vaccination in the decrease of measles incidence in Italy

In Italy, during the course of the past century to the present-day, measles incidence underwent a remarkable decreasing trend that started well before the introduction of the national immunization programme. In this work, we aim at examining to what extent both the demographic transition, characterized by declining mortality and fertility rates over time, and the vaccination programme are responsible for the observed epidemiological pattern. Making use of a non-stationary, age-structured disease transmission model, we show that in the pre-vaccination era, from 1901 to 1982, the decline in birth rates has resulted in a drastic decrease in the effective transmission rate, which in turn has determined a declining trend of measles incidence (from 25.2 to 10.3 infections per 1000 individuals). However, since 1983, vaccination appears to have become the major contributing factor in the decrease of measles incidence, which otherwise would have remained stable as a consequence of the nearly constant birth rates. This led to a remarkable decrease in the effective transmission rate, to a level well below the critical threshold for disease persistence. These findings call for the adoption of epidemiological models, which deviate the age structure from stationary equilibrium solutions, to better understand the biology of infectious diseases and evaluate immunization programmes.

Monitoring progress towards the elimination of measles in China: an analysis of measles surveillance data

OBJECTIVE

To analyse the epidemiology of measles in China and determine the progress made towards the national elimination of the disease.

METHODS

We analysed measles surveillance data - on the age, sex, residence and vaccination status of each case and the corresponding outcome, dates of onset and report and laboratory results - collected between January 2005 and October 2013.

FINDINGS

Between 2005 and October 2013, 596 391 measles cases and 368 measles-related deaths were reported in China. Annual incidence, in cases per 100 000 population, decreased from 9.95 in 2008 to 0.46 in 2012 but then rose to more than 1.96 in 2013. The number of provinces that reported an annual incidence of less than one case per million population increased from one in 2009 to 15 in 2012 but fell back to one in 2013. Median case age decreased from 83 months in 2005 to 14 months in 2012 and 11 months in January to October 2013. Between 2008 and 2012, the incidence of measles in all age groups, including those not targeted for vaccination, decreased by at least 93.6%. However, resurgence started in late 2012 and continued into 2013. Of the cases reported in January to October 2013, 40% were aged 8 months to 6 years.

CONCLUSION

Although there is evidence of progress towards the elimination of measles from China, resurgence in 2013 indicated that many children were still not being vaccinated on time. Routine immunization must be strengthened and the remaining immunity gaps need to be identified and filled.

Barriers to the vaccination of children and adolescents and possible solutions

The benefits of vaccination are clearly demonstrated by the eradication or enormous decline in the incidence of many vaccine-preventable diseases, but the coverage of many highly recommended vaccines is still frequently inadequate and children continue to suffer from diseases that could have been prevented. The main aim of this paper is to discuss the recognized barriers to the vaccination of children and adolescents confronting national health systems, providers and parents, and the ways in which they can be overcome. Most of the problems underlying limited vaccination coverage among children are due to a lack of understanding on the part of healthcare providers and parents, which underlines the need for educational programmes specifically addressed to each of these groups. It is also essential that all of the physicians providing immunization develop approaches that acknowledge parents' concerns and respectfully try to correct any misinformation. Other means of extending vaccine coverage include the implementation of adequate systems for recording vaccine administration and the activation of effective reminder/recall systems, the provision of immunization services in some medical care specialties or by integrating healthcare sites, and the elimination or reduction of all the problems that currently limit access to vaccination services. However, it will take the combined efforts of healthcare systems and providers to pull down all of the barriers.