The clinical significance of measles: a review

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

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

Progress in the elimination of measles and congenital rubella in Central Italy

Despite the launch of a WHO European Region strategic plan 2005-2010 for eliminating measles and rubella and preventing congenital rubella (CR) infection, measles and rubella are still circulating in Europe. Increased transmission and outbreaks of measles in Europe were still observed in 2011. In Italy, the objectives of the National Plan (2003-2007) for measles elimination have not yet been achieved. The goal of measles elimination and incidence reduction of CR cases has been postponed to 2015 by the Italian Ministry of Health through the implementation of the new National Plan 2010-2015 which will require (1) the achievement of more than 95% coverage with 1 dose and two doses of measles containing vaccine (MCV), respectively, within 24 mo and within 12 y of age; (2) supplementary vaccination activities aimed at susceptible populations including adolescents, young adults and those at risk (health care and educational workers, military, groups "hard to reach" like nomads); and in addition, (3) reduction to less than 5% in the proportion of susceptible women of childbearing age (especially immigrant women). Experiences at regional level, like in Tuscany, have shown promising results in order to create an integrated surveillance system between regional and local health authorities, university and laboratory and in the future, to validate elimination. Moreover, the evaluation of all preventive activities performed in Tuscany during the last decade, immunization coverage data, sero-epidemiological population profile and incidence of measles and rubella cases has highlighted critical points which should be improved and good practices already implemented which should be maintained in the future in order to reach the new goals.

DHEA inhibits measles virus through a mechanism independent of its ability to modulate the Raf/MEK/ERK signaling pathway

Aim: Despite the existence of an effective vaccine, measles infection is still frequent in many developing countries with reduced health infrastructure, and it is one of the major causes of child death globally. In the past decade numerous outbreaks have occurred in developed countries, giving a fresh impetus to antiviral research against measles virus. The aim of this study was to investigate the antiviral activity of the natural steroid hormone DHEA against measles virus and the role of the Raf/MEK/ERK signaling pathway in viral multiplication and DHEA’s antiviral activity. Materials & methods: The antiviral activity of DHEA and two ERK modulators, UO126 and anisomycin, was determined using a virus yield reduction assay. Furthermore, we studied DHEA’s virucidal activity and the viral multiplication step affected by the compound. The effect of virus infection on the Raf/MEK/ERK pathway and the activity of those compounds against measles virus spread and induced cytopathic effect were studied using western blot and indirect immunofluorescence. Results & conclusion: We found that DHEA and UO126 are active against measles virus and that they are able to diminish virus-induced cytopathic effects. Also, our study showed that early events in the viral multiplication cycle trigger ERK activation, suggesting that DHEA, a Raf/MEK/ERK modulator, may not exert its antiviral activity through the modulation of this pathway. Our results may provide a first step in the development of new antiviral agents against measles virus.

Measles virus and associated central nervous system sequelae

Worldwide, measles remains one of the most deadly vaccine-preventable diseases. In the United States, enrollment in the public schools requires that each child receives 2 doses of measles-containing vaccine before entry, essentially eliminating this once endemic disease. Recent outbreaks of measles in the United States have been associated with importation of measles virus from other countries and subsequent transmission to intentionally undervaccinated children. The central nervous system complications of measles can occur within days or years of acute infection and are often severe. These include primary measles encephalitis, acute postinfectious measles encephalomyelitis, measles inclusion body encephalitis, and subacute sclerosing panencephalitis. These measles-associated central nervous system diseases differ in their pathogenesis and pathologic effects. However, all involve complex brain-virus-immune system interactions, and all can lead to severe and permanent brain injury. Despite better understanding of the clinical presentations and pathogenesis of these illnesses, effective treatments remain elusive.

Measles outbreak in Burkina Faso, 2009: a case-control study to determine risk factors and estimate vaccine effectiveness

OBJECTIVE

We investigated a large measles outbreak that occurred in 2009 in Burkina Faso in order to describe the epidemic, assess risk factors associated with measles, and estimate measles vaccine effectiveness.

METHODS

We reviewed national surveillance and measles vaccine coverage data, and conducted a case-control study in three geographic areas. Case-patients were randomly selected from the national case-based measles surveillance database or, when a case-patient could not be traced, were persons in the same community who experienced an illness meeting the WHO measles clinical case definition. Controls were matched to the same age stratum (age 1-14 years or age 15-30 years) and community as case-patients. Risk factors were assessed using conditional logistic regression.

RESULTS

Lack of measles vaccination was the main risk factor for measles in all three geographic areas for children aged 1-14 years (adjusted matched odds ratio [aMOR] [95% confidence interval (CI)], 19.4 [2.4-155.9], 5.9 [1.6-21.5], and 6.4 [1.8-23.0] in Bogodogo, Zorgho, and Sahel, respectively) and persons aged 15-30 years (aMOR [95% CI], 3.2 [1.1-9.7], 19.7 [3.3-infinity], 8.0 [1.8-34.8] in Bogodogo, Zorgho, and Sahel, respectively). Among children aged 1-14 years, VE of any measles vaccination prior to 2009 was 94% (95% CI, 45-99%) in Bogodogo, 87% (95% CI, 37-97%) in Zorgho, and 84% (95% CI, 41-96%) in Sahel. Main reasons for not receiving measles vaccination were lack of knowledge about vaccination campaigns or need for measles vaccination and absence during vaccination outreach or campaign activities.

CONCLUSION

These results emphasize the need for improved strategies to reduce missed opportunities for vaccination and achieve high vaccination coverage nationwide in order to prevent large measles outbreaks and to continue progress toward measles mortality reduction.

Measles

Measles is a highly contagious disease caused by measles virus and is one of the most devastating infectious diseases of man--measles was responsible for millions of deaths annually worldwide before the introduction of the measles vaccines. Remarkable progress in reducing the number of people dying from measles has been made through measles vaccination, with an estimated 164,000 deaths attributed to measles in 2008. This achievement attests to the enormous importance of measles vaccination to public health. However, this progress is threatened by failure to maintain high levels of measles vaccine coverage. Recent measles outbreaks in sub-Saharan Africa, Europe, and the USA show the ease with which measles virus can re-enter communities if high levels of population immunity are not sustained. The major challenges for continued measles control and eventual eradication will be logistical, financial, and the garnering of sufficient political will. These challenges need to be met to ensure that future generations of children do not die of measles.

The clinical epidemiology of pediatric patients with measles from 2000 to 2009 in shanghai, china

Measles remains a leading vaccine-preventable cause of child mortality worldwide. The incidence has increased recently in some areas. The authors retrospectively analyzed the epidemiological and clinical characteristics of 2473 measles patients in Shanghai from 2000 to 2009. There were 1909 measles cases during 2005-2009 (group II), whereas only 564 cases were reported during 2000-2004 (group I). In total, 60.87% patients in group II were younger than 9 months, which was significantly higher than that in group I (35.28%; P < .001). More complications, death cases, and less atypical rashes were found in recent years. In addition, 2181 of all the 2473 patients (88.19%) and 1112 of 1328 hospitalized children (83.73%) had not been vaccinated; most of them were immigrants. The results indicated that the rising number of immigrants accounted for the increased measles morbidity in Shanghai. The tendency of more young patients and increased complications suggest that some adjustments might be needed in vaccination administration and therapeutic strategy.

Measles outbreak on a college campus transmitted through internet cafés

BACKGROUND

During March 2008, a college in Urumqi, capital of Xinjiang Uygur Autonomous Region in China, reported a measles outbreak, amid a city-wide outbreak involving >2700 cases.

METHODS

Suspected case patients were defined as patients with onset of fever (≥38°) and rash between 7 March and 30 April 2008. Probable case patients were defined as suspected case patients with >3 days of rash or known exposure to someone with laboratory-confirmed measles. Confirmed case patients were defined as suspected or probable case patients with Koplik spots or positive titer for immunoglobulin M antibody. We conducted a case-control investigation to identify risk factors for transmission.

RESULTS

We identified 162 suspected (attack rate, 1.9%), 99 probable, and 62 confirmed case patients. The epidemic curve indicated a point source initially, followed by person-to-person transmission. Approximately 63% of 90 probable case patients and 27% of 150 asymptomatic student controls randomly selected among classmates of student case patients visited internet cafés during the exposure period (odds ratio [OR], 4.5; 95% confidence interval [CI], 2.6-8.0); 66% of case patients and 45% of student controls reported close contact with a measles case patient (OR, 2.3; 95% CI, 1.3-3.9). In stratified analysis, visiting internet cafés (OR, 4.0; 95% CI, 1.5-11) remained significantly associated with disease, but contact with case patients (OR, 1.9; 95% CI, .79-4.4) became nonsignificant.

CONCLUSIONS

This measles outbreak was transmitted in internet cafés, followed by secondary transmission. Chinese universities should require proof of immunity or 2 doses of measles vaccine at college entry.

Using cost-effectiveness analysis to support research and development portfolio prioritization for product innovations in measles vaccination

BACKGROUND

Several potential measles vaccine innovations are in development to address the shortcomings of the current vaccine. Funders need to prioritize their scarce research and development resources. This article demonstrates the usefulness of cost-effectiveness analysis to support these decisions.

METHODS

This study had 4 major components: (1) identifying potential innovations, (2) developing transmission models to assess mortality and morbidity impacts, (3) estimating the unit cost impacts, and (4) assessing aggregate cost-effectiveness in United Nations Children's Fund countries through 2049.

RESULTS

Four promising technologies were evaluated: aerosol delivery, needle-free injection, inhalable dry powder, and early administration DNA vaccine. They are projected to have a small absolute impact in terms of reducing the number of measles cases in most scenarios because of already improving vaccine coverage. Three are projected to reduce unit cost per dose by $0.024 to $0.170 and would improve overall cost-effectiveness. Each will require additional investments to reach the market. Over the next 40 years, the aggregate cost savings could be substantial, ranging from $98.4 million to $689.4 million.

CONCLUSIONS

Cost-effectiveness analysis can help to inform research and development portfolio prioritization decisions. Three new measles vaccination technologies under development hold promise to be cost-saving from a global perspective over the long-term, even after considering additional investment costs.

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.

Extreme mortality after first introduction of measles virus to the polynesian island of Rotuma, 1911

Rotuma is an isolated Polynesian island. In January 1911, most residents of Rotuma (population approximately 2,600) were exposed to measles virus for the first time. The official mortality register documented 491 deaths due to all causes among Rotumans during 1911 (cumulative measles-related mortality: 12.8%); most deaths occurred in April-May and were attributed to measles and its sequelae. Measles-related mortality rates were higher among young children (23.4 per 100 person-years) and young adults (17.1 per 100 person-years) than among adolescents (11.0 per 100 person-years) and older adults (5.6 per 100 person-years); females (16.2 per 100 person-years) died at a higher rate than males (13.2 per 100 person-years). Gastrointestinal complications (75%), not respiratory complications, were the predominant clinical manifestations of fatal measles cases; tuberculosis mortality was unusually high during the year of the epidemic. In 1911, measles-related mortality varied by nearly 3-fold across geographic districts (range, 7.4%-21.6%). The extreme mortality due to measles on Rotuma typifies the experiences of isolated populations after first encounters with measles; it suggests that prior exposures to a narrow range of microbes and genetic homogeneity predispose isolated populations to lethal outcomes when they are first exposed to highly contagious and pathogenic viruses (e.g., measles, influenza).

Low measles seropositivity rate among children and young adults: a sero-epidemiological study in southern China in 2008

To obtain sero-epidemiological profile and develop optimal strategies to promote measles elimination, we conducted a measles seroprevalence study using stratified sampling method in Guangzhou, southern China in 2008. 4036 samples were analyzed by the enzyme-linked immunosorbent assay method and the overall sero-positive rate of measles antibody was 70.6% (95% CI 69.2-72.0%). Positive seroprevalences differed among age groups (P=0.000) and a W-curve distribution was observed. The 15-29 years group had the low positive rate of 58.8% (95% CI 54.9-62.7%). Catch-up vaccination campaigns should be promoted among susceptible population of ≤ 29 year olds including women of childbearing age.

Detection of measles virus RNA on SYBR green real-time reverse transcription-polymerase chain reaction

BACKGROUND

As the coverage rate of the measles vaccine increases, not all patients present the typical symptoms of measles after exposure to the measles virus (MV). The virus loads in clinical specimens from patients with vaccine-modified non-typical measles are expected to be low compared with those of primary MV infection. A rapid and sensitive laboratory procedure is required for diagnosis of measles.

METHODS

SYBR Green (TaKaRa) and TaqMan (ABI) real-time reverse transcription-polymerase chain reaction (RT-PCR) assays were developed to detect MV-RNA. For the real-time RT-PCR, primer sets were designed from a region of the MV H gene of the Edmonston strain (genotype A). A TaqMan probe specific for the H gene of genotype D MV was used. The minimum detectable level of MV-RNA in the SYBR Green and TaqMan real-time RT-PCR assays was evaluated using synthetic MV-RNA. The sensitivity of real-time RT-PCR was compared with that of nested RT-PCR and the virus isolation method using throat swabs and peripheral blood samples from patients with measles.

RESULTS

The minimum detectable level of RNA was 10 and 10(2) copies for SYBR Green RT-PCR and TaqMan RT-PCR, respectively. Ten-10(6) copies of standard RNA were linearly detected on SYBR Green RT-PCR. The sensitivity of SYBR Green RT-PCR was equal to that of nested RT-PCR. MV-RNA was detected in virus isolation-negative throat swabs on SYBR Green RT-PCR.

CONCLUSION

SYBR Green RT-PCR is a highly sensitive, rapid, and useful diagnostic procedure for the detection of MV.

Challenges in measuring measles case fatality ratios in settings without vital registration

Measles, a highly infectious vaccine-preventable viral disease, is potentially fatal. Historically, measles case-fatality ratios (CFRs) have been reported to vary from 0.1% in the developed world to as high as 30% in emergency settings. Estimates of the global burden of mortality from measles, critical to prioritizing measles vaccination among other health interventions, are highly sensitive to the CFR estimates used in modeling; however, due to the lack of reliable, up-to-date data, considerable debate exists as to what CFR estimates are appropriate to use. To determine current measles CFRs in high-burden settings without vital registration we have conducted six retrospective measles mortality studies in such settings. This paper examines the methodological challenges of this work and our solutions to these challenges, including the integration of lessons from retrospective all-cause mortality studies into CFR studies, approaches to laboratory confirmation of outbreaks, and means of obtaining a representative sample of case-patients. Our experiences are relevant to those conducting retrospective CFR studies for measles or other diseases, and to those interested in all-cause mortality studies.

Blue moon neurovirology: the merits of studying rare CNS diseases of viral origin

While measles virus (MV) continues to have a significant impact on human health, causing 150,000-200,000 deaths worldwide each year, the number of fatalities that can be attributed to MV-triggered central nervous system (CNS) diseases are on the order of a few hundred individuals annually (World Health Organization 2009). Despite this modest impact, substantial effort has been expended to understand the basis of measles-triggered neuropathogenesis. What can be gained by studying such a rare condition? Simply stated, the wealth of studies in this field have revealed core principles that are relevant to multiple neurotropic pathogens, and that inform the broader field of viral pathogenesis. In recent years, the emergence of powerful in vitro systems, novel animal models, and reverse genetics has enabled insights into the basis of MV persistence, the complexity of MV interactions with neurons and the immune system, and the role of immune and CNS development in virus-triggered disease. In this review, we highlight some key advances, link relevant measles-based studies to the broader disciplines of neurovirology and viral pathogenesis, and propose future areas of study for the field of measles-mediated neurological disease.

Controversies in vaccine mandates

Policies that mandate immunization have always been controversial. The controversies take different forms in different contexts. For routine childhood immunizations, many parents have fears about both short- and long-term side effects. Parental worries change as the rate of vaccination in the community changes. When most children are vaccinated, parents worry more about side effects than they do about disease. Because of these worries, immunization rates go down. As immunization rates go down, disease rates go up, and parents worry less about side effects of vaccination and more about the complications of the diseases. Immunization rates then go up. For teenagers, controversies arise about the criteria that should guide policies that mandate, rather than merely recommend and encourage, certain immunizations. In particular, policy makers have questioned whether immunizations for human papillomavirus, or other diseases that are not contagious, should be required. For healthcare workers, debates have focused on the strength of institutional mandates. For years, experts have recommended that all healthcare workers be immunized against influenza. Immunizations for other infections including pertussis, measles, mumps, and hepatitis are encouraged but few hospitals have mandated such immunizations-instead, they rely on incentives and education. Pandemics present a different set of problems as people demand vaccines that are in short supply. These issues erupt into controversy on a regular basis. Physicians and policy makers must respond both in their individual practices and as advisory experts to national and state agencies. The articles in this volume will discuss the evolution of national immunization programs in these various settings. We will critically examine the role of vaccine mandates. We will discuss ways that practitioners and public health officials should deal with vaccine refusal. We will contrast responses of the population as a whole, within the healthcare setting, and in the setting of pandemic influenza.

Measles-related hospitalizations and complications in Japan, 2007-2008

OBJECTIVE

In the present study we aim to describe the clinical features and related complications of severe measles requiring hospitalization in Japan in 2007 and 2008.

METHODS

We extracted the records of patients diagnosed with measles between July and December in 2007 and 2008 from the Diagnosis Procedure Combination (DPC) inpatient database and the verified age distribution of patients with measles requiring hospitalization and the rate of measles-related complications. We also examined the rate of measles patients who were pregnant or had malignancies.

RESULTS

We identified 1,037 inpatients in 377 hospitals; 879 in 2007 and 158 in 2008. Overall, 554 (53.4%) were male. Patient age distribution showed two peaks; ≤4 years (21%) and 15-29 years (45%). Ninety (8.7%) patients had pneumonia, 22 (2.1%) had encephalitis, 7 (0.7%) had intestinal complications, 7 (0.7%) had conjunctivitis, 6 (0.6%) had meningitis, and 4 (0.4%) had otitis media. Patients aged ≤14 years were significantly more likely to have pneumonia (16.4%; p<0.001). The rate of encephalitis was relatively low in patients aged ≤14 years (0.9%) compared with those aged 15-29 years (3.0%) and those aged ≥30 years (2.0%); the difference was not statistically significant (p=0.141). Of 31 pregnant women, 10 had spontaneous abortion or stillbirth. Twenty-eight patients had malignancies.

CONCLUSION

The present study adds important information to our knowledge of the clinical features of severe measles. Follow-up monitoring of the trends of this distressing disease using the DPC database will be essential.

Common acute childhood infections and appendicitis: a historical study of statistical association in 27 English public boarding schools, 1930-1934

Although the involvement of common childhood infections in the aetiology of acute appendicitis has long been conjectured, supporting evidence is largely restricted to a disparate set of clinical case reports. A systematic population-based analysis of the implied comorbid associations is lacking in the literature. Drawing on a classic epidemiological dataset, assembled by the School Epidemics Committee of the United Kingdom's Medical Research Council (MRC) in the 1930s, this paper presents a historical analysis of the association between termly outbreaks of each of six common childhood infections (chickenpox, measles, mumps, rubella, scarlet fever and whooping cough) and operated cases of acute appendicitis in 27 English public boarding schools. When controlled for the potential confounding effects of school, year and season, multivariate negative binomial regression revealed a positive association between the level of appendicitis activity and the recorded rate of mumps (beta=0.15, 95% CI 0.07-0.24, P<0.001). Non-significant associations were identified between appendicitis and the other sample infectious diseases. Subject to data caveats, our findings suggest that further studies are required to determine whether the comorbid association between mumps and appendicitis is causal.

Putting synthesis into biology: a viral view of genetic engineering through de novo gene and genome synthesis

The rapid improvements in DNA synthesis technology hold the potential to revolutionize biosciences in the near future. Traditional genetic engineering methods are template dependent and make extensive but laborious use of site-directed mutagenesis to explore the impact of small variations on an existing sequence “theme.” De novo gene and genome synthesis frees the investigator from the restrictions of the pre-existing template and allows for the rational design of any conceivable new sequence theme.

Viruses, being among the simplest replicating entities, have been at the forefront of the advancing biosciences since the dawn of molecular biology. Viral genomes, especially those of RNA viruses, are relatively short, often less than 10,000 bases long, making them amenable to whole genome synthesis with the currently available technology. For this reason viruses are once again poised to lead the way in the budding field of synthetic biology—for better or worse.

Retinoids inhibit measles virus through a type I IFN-dependent bystander effect

Measles-associated mortality can be decreased in response to treatment with vitamin A. Our goal was to understand the mechanism by which vitamin A and other retinoids reduce measles virus (MeV) replication in vitro. MeV is known to inhibit type I interferon (IFN) signaling, and retinoids are increasingly implicated in modulating innate immunity. Type I IFN blocking antibodies abrogated the inhibitory effects of all-trans retinoic acid (ATRA) on MeV replication (EC(50) of ATRA: 3.17 x 10(-8) M). IFN-stimulated genes (ISGs) are up-regulated by ATRA in MeV-infected U937 cell cultures starting at 12 h and reaching a plateau at 24 h postinfection when compared to either treatment or infection alone. We found that this increased gene expression occurs in uninfected cells by using a transwell system where the uninfected cells were separated from infected cells by a membrane with 0.02-muM pores. Uninfected bystander cells from the ATRA-treated transwells did not support substantial viral replication when subsequently infected with MeV. In the absence of ATRA, the cells from the uninfected chamber did not up-regulate ISG expression and were not protected from subsequent challenge with virus. These results demonstrate that retinoids inhibit MeV replication by up-regulating elements of the innate immune response in uninfected bystander cells, making them refractory to productive infection during subsequent rounds of viral replication.

Scheduling of measles vaccination in low-income countries: projections of a dynamic model

Large-scale vaccination campaigns (SIAs) and improved routine immunization (RI) have greatly reduced measles incidence in low-income countries. However, the interval between SIAs required to maintain these gains over the long term is not clear. We developed a dynamic model of measles transmission to assess measles vaccination strategies in Cambodia, Ghana, India, Morocco, Nigeria, and Uganda. We projected measles cases from 2008 to 2050 under (a) holding SIAs every 2, 4, 6, or 8 years, (b) improvements in first dose routine measles vaccine (MCV1) coverage of 0%, 1%, 3% annually, and (c) introducing MCV2 once MCV1 coverage reaches 70%, 80%, 90%. If MCV1 continues improving, then India and Nigeria could hold SIAs every 4 years without significant probability of large outbreaks, and the other countries every 6-8 years. If RI remains stagnant, India and Nigeria should hold SIAs every 2 years, and the other countries every 4-6 years.

Endemic measles in Karachi, Pakistan and validation of IMCI criteria for measles

AIM

To estimate the incidence of measles in Karachi, Pakistan and to determine the proportion of children with measles based on the WHO integrated management of childhood illness (IMCI) criteria with a positive IgM for measles or dengue.

METHODS

Patients up to 14 years old were screened for febrile rash illnesses at five Karachi hospitals. Active measles cases were classified as measles, measles with eye and mouth complications, or severe complicated measles using IMCI criteria.

RESULTS

Screening 1,219,061 patients over a 39-month period identified 3503 qualified children. Most (76.8%) measles cases occurred in children under five years of age. The average annual incidence rate was 0.68 per 1000 in year 1; 0.19 in year 2 and 0.08 in year 3 of surveillance. Pneumonia and diarrhoea were the most common complications. Of 18.1% hospitalized, 1.6% died. Of 2286 children tested, 1599 (69.9%) were measles IgM positive. Of 542 measles IgM negative children, 66 (12%) were dengue IgM positive. The predictive positive value for the IMCI case definition was 75%.

CONCLUSION

The IMCI case definitions for measles is reasonable but may overestimate measles incidence. Measles continues to be a public health problem in Pakistan; increased efforts to control measles are urgently needed.

Measles, mumps, and rubella in Finland: 25 years of a nationwide elimination programme

A nationwide programme to eliminate indigenous measles, mumps, and rubella, mainly by vaccinating children twice, was launched in Finland in 1982. Strong scientific methods to examine the immunological, clinical, and epidemiological variables have accompanied the programme. Measles was eliminated in 1996, and mumps and rubella in 1997. Now, 25 years from the start of this programme, Finland is facing new challenges. Since elimination, eight, 32, and six cases of measles, mumps, and rubella, respectively, have been reported. Of those, seven cases were failures of mumps vaccinations and one case was a rubella vaccination failure. Although outbreaks have been averted, the risks are increasing because the unvaccinated population is growing, epidemics occur in nearby countries, breakthrough cases arise, and declining antibodies suggest waning immunity. The chances for natural boosters are now at a minimum, and individuals are increasingly protected solely by vaccination. To maintain the absence of these diseases, the adopted policy should continue, but the country should also be prepared for prompt supplementary vaccinations in the case of epidemic outbreaks.

Routine immunization of adults in Canada: Review of the epidemiology of vaccine-preventable diseases and current recommendations for primary prevention

Vaccination is one of the greatest achievements in public health of the 20th century. However, the success of vaccine uptake and adherence to immunization guidelines seen in pediatric populations has not been observed among adult Canadians. As a result of the disparity in susceptibility to vaccine-preventable disease, there has been an increasing shift of vaccine-preventable childhood diseases into adult populations. Accordingly, morbidity and mortality due to vaccine-preventable illnesses now occur disproportionately in adults. All Canadians, irrespective of age, should have immunity to measles, mumps, rubella, tetanus, diphtheria, pertussis and varicella. All adult Canadians with significant medical comorbidities or those older than 65 years of age should receive the pneumococcal polysaccharide vaccine and yearly trivalent inactivate influenza vaccines. The present review summarizes the burden of illness of these vaccine-preventable diseases in the Canadian adult population and reviews the current immunization recommendations. Vaccination of all Canadians to these common agents remains a vital tool to decrease individual morbidity and mortality and reduce the overall burden of preventable disease in Canada.

Antiviral therapy for respiratory tract infections

Viruses are important pathogens causing respiratory tract infections both in the community and health-care facility settings. They are extremely common causes of morbidity in the competent hosts and some are associated with significant mortality in the compromised individuals. With wider application of molecular techniques, novel viruses are being described and old viruses are found to have new significance in different epidemiological and clinical settings. Some of these emerging pathogens may have the potential to cause pandemics or global spread of a severe disease, as exemplified by severe acute respiratory syndrome and avian influenza. Antiviral therapy of viral respiratory infections is often unnecessary in the competent hosts because most of them are selflimiting and effective agents are not always available. In the immunocompromised individuals or for infections caused by highly pathogenic viruses, such as avian influenza viruses (AIV), antiviral treatment is highly desirable, despite the fact that many of the agents may not have undergone stringent clinical trials. In immunocompetent hosts, antiviral therapy can be stopped early because adaptive immune response can usually be mounted within 5-14 days. However, the duration of antiviral therapy in immunosuppressed hosts depends on clinical and radiological resolution, the degree and duration of immunosuppression, and therefore maintenance therapy is sometimes needed after the initial response. Immunotherapy and immunoprophylaxis appear to be promising directions for future research. Appropriate and targeted immunomodulation may play an important adjunctive role in some of these infections by limiting the extent of end-organ damage and multi-organ failure in some fulminant infections.

Antibiotics for preventing complications in children with measles

BACKGROUND

Measles is the leading killer among vaccine-preventable diseases, responsible for an estimated 44% of the 1.7 million vaccine-preventable deaths among children annually.

OBJECTIVES

To assess the effects of antibiotics given to children with measles to prevent complications and reduce pneumonia, other morbidities and mortality.

SEARCH STRATEGY

In this 2008 update we searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2008, Issue 1) MEDLINE (1966 to January week 1, 2008), EMBASE (1980 to December 2007) and the National Research Register (Issue 3, 2007).

SELECTION CRITERIA

Randomized controlled trials (RCTs) and quasi-RCTs comparing antibiotics with placebo or no treatment to prevent complications in children with measles.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality.

MAIN RESULTS

Seven trials with 1385 children were included. Pooled study data showed that the incidence of pneumonia was lower in the treatment group compared to the control group. However, the difference was not statistically significant. In children who received antibiotics, 1.9% developed pneumonia, while in the control group 6% developed pneumonia (OR 0.28; 95% CI 0.06 to 1.25). The one trial that showed an increase in the rate of pneumonia with antibiotics was conducted in 1942 and compared oral sulfathiazole with symptomatic treatment. If the results of this trial are removed from the meta-analysis, and the remaining six studies are combined, there is a statistically significant reduction in the incidence of pneumonia in children receiving antibiotics (OR 0.17; 95% CI 0.05 to 0.65). The number needed to treat to prevent one episode of pneumonia is 24 patients. The incidence of other complications was significantly lower in children receiving antibiotics: purulent otitis media (OR 0.34; 95% CI 0.16 to 0.73) and tonsillitis (OR 0.08; 95% CI 0.01 to 0.72). There was no difference in the incidence of conjunctivitis (OR 0.39; 95% CI 0.15 to 1.0), diarrhea (OR 0.53; 95% CI 0.23 to 1.22) or croup (OR 0.16; 95% CI 0.01 to 4.06).

AUTHORS' CONCLUSIONS

This review suggests a beneficial effect of antibiotics in preventing complications such as pneumonia, purulent otitis media and tonsillitis in children with measles. On the basis of this review, it is not possible to give definitive guidelines on the type of antibiotic, duration, or the day of initiation. Use of penicillin or co-trimoxazole may be considered. There is a need to generate more evidence by well planned RCTs to answer these questions.

Retinoids inhibit measles virus in vitro via nuclear retinoid receptor signaling pathways

Measles virus (MV) infects 30 million children every year, resulting in more than half a million deaths. Vitamin A (retinol) treatment of acute measles can reduce measles-associated mortality by 50-80%. We sought to determine whether or not retinoids can act directly to limit MV output from infected cells. Physiologic concentrations of retinol were found to inhibit MV output in PBMC and a range of cell lines of epithelial and endothelial origin (40-50%). Near complete inhibition of viral output was achieved in some cells/lines treated with all-trans retinoic acid (ATRA) and 9-cis RA (9cRA). Important attenuation of the anti-MV effect of retinoids in R4 cells, a subclone of a retinoid-responsive cell line (NB4) deficient in RAR signaling, demonstrates that this effect is mediated at least in part by nuclear retinoid receptor signaling pathways. Inhibition of MV replication could not be fully explained as a result of retinoid effects on cell differentiation, proliferation or viability, particularly at low retinoid concentrations (1-10nM). These data provide the first evidence that retinoids can directly inhibit MV in vitro, and raise the possibility that retinoids may have similar actions in vivo.

HIV type 1 infection is a risk factor for mortality in hospitalized Zambian children with measles

BACKGROUND

Measles remains a significant cause of vaccine-preventable mortality in sub-Saharan Africa, yet few studies have investigated risk factors for measles mortality in regions of high human immunodeficiency virus type 1 (HIV-1) prevalence.

METHODS

Between January 1998 and July 2003, children with clinically diagnosed measles who were hospitalized at the University Teaching Hospital in Lusaka, Zambia, were enrolled in an observational study. Demographic and clinical information was recorded at enrollment and at discharge or death. Measles was confirmed by detection of antimeasles virus immunoglobulin M antibodies, and HIV-1 infection was confirmed by detection of HIV-1 RNA.

RESULTS

Of 1474 enrolled children, 1227 (83%) had confirmed measles and known HIV-1 infection status. Almost one-third of the HIV-1-infected children with measles were <9 months of age, the age of routine measles vaccination, compared with one-fourth of the uninfected children (P = .07). Death occurred during hospitalization in 23 (12.2%) of the HIV-1-infected children and 45 (4.3%) of the HIV-1-uninfected children (p < .001) with measles. After adjusting for age, sex, and measles vaccination status, HIV-1 infection (odds ratio, 2.5; 95% confidence interval, 1.4-4.6), < or =8 years of maternal education (odds ratio, 2.4; 95% confidence interval, 1.2-4.8), and the presence of a desquamating rash (odds ratio, 2.2, 95% confidence interval, 1.3-3.6) were significant predictors of mortality due to measles.

CONCLUSIONS

In a region of high HIV-1 prevalence, coinfection with HIV-1 more than doubled the odds of death in hospitalized children with measles. Increased mortality among HIV-1-infected children is further evidence that greater efforts are necessary to reduce transmission of the measles virus in regions of high HIV-1 prevalence.

Remaining measles challenges in Australia

Measles is now rare in Australia, and cases can usually be linked to its importation from endemic countries. To prevent measles outbreaks in Australia, high vaccination coverage with two doses of vaccine must be sustained. All medical practitioners should consider a diagnosis of measles in a patient of any age who presents with fever and a non-vesiculating, non-itchy rash. If measles is suspected clinically, public health authorities should be immediately notified, so that testing and management of patients can be discussed and contact tracing initiated. When a patient is suspected of having measles, testing of a serum sample for measles-specific IgM and IgG antibodies should be requested urgently. Pathology laboratories should have effective protocols for immediately reporting positive measles-specific IgM antibody tests, or other results indicative of measles, to public health authorities.

Disease manifestations of canine distemper virus infection in ferrets are modulated by vitamin A status

The measles virus (MV) causes half a million childhood deaths annually. Vitamin A supplements significantly reduce measles-associated mortality and morbidity. The mechanisms whereby vitamin A acts against MV are not understood and currently there is no satisfactory small animal model for MV infection. We report on the development of a ferret model to study antiviral activity of vitamin A against canine distemper virus (CDV). CDV is closely related to MV at the molecular level and distemper in ferrets mimics measles in humans. We infected vitamin A-replete (control) and vitamin A-depleted ferrets with CDV and assessed the ability of high-dose vitamin A supplements to influence CDV disease. In control ferrets, CDV infection caused fever, rash, conjunctivitis, cough, coryza, and diarrhea. In contrast, control ferrets that were given 30 mg of vitamin A did not develop typical distemper after infection and exhibited only a mild rash. The supplement did not negatively affect ferret health and resulted in a 100% increase in serum and liver vitamin A concentrations. We also found that profound vitamin A deficiency is inducible in ferrets and can be rapidly reversed upon high-dose vitamin A supplementation. Vitamin A deficiency caused anorexia, diarrhea, cataracts, behavioral abnormalities, and ultimately death, with or without CDV infection. All ferrets that received vitamin A supplements, however, recovered uneventfully from CDV infection. These results replicate many aspects of the observations of vitamin A therapy in humans with measles and suggest that CDV infection in ferrets is an appropriate model for the study of the antiviral mechanism of vitamin A.

Risk of serious neurologic disease after immunization of young children in Britain and Ireland

OBJECTIVE

We sought to investigate the risk of serious neurologic disease after immunization in early childhood.

METHODS

The results of a 3-year prospective study of children (2-35 months old) in Britain and Ireland with encephalitis and/or severe illness with convulsions and fever were linked to each child's vaccine history. Cases were reported via the British Paediatric Surveillance Unit's network. The self-controlled case-series method was used to investigate associations between immunization and acute potential adverse events. The risk periods investigated were 0 to 3 and 0 to 7 days post-diphtheria, tetanus, whole cell pertussis, Haemophilus influenzae type b or meningococcal C conjugate vaccine and 6 to 11 and 15 to 35 days post-measles, mumps, rubella vaccine.

RESULTS

A total of 157 disease episodes from 155 children met the analytical case definition. There were 11 cases of herpes simplex encephalitis and 23 cases of primary human herpesvirus 6 and/or 7 infection. There was no evidence of a raised relative incidence of serious neurologic disease in any of the specified risk periods with the exception of a raised relative incidence of 5.68 in the 6-11 days after measles, mumps, rubella vaccine. Based on this relative incidence, between 3 and 6 of the 6 cases in this period were estimated to be attributable to the vaccine with a best estimate of 5. The 6 cases all had fever with convulsions lasting >30 minutes; in all but 1, there was complete recovery by discharge from hospital. Of the 5 patients who recovered, 1 had a concurrent primary human herpesvirus 6 infection and one a primary human herpesvirus 7.

CONCLUSIONS

Six to 11 days after measles, mumps, rubella vaccine there is an increased risk of fever and convulsions lasting >30 minutes. All 6 of the episodes temporally related to immunization met the criteria for complex febrile convulsions. The estimated attributable risk of serious neurological disease was similar to that previously found for measles vaccine.

Health burden and economic impact of measles-related hospitalizations in Italy in 2002-2003

Background

A large measles outbreak occurred in Italy in 2002–2003. This study evaluates the health burden and economic impact of measles-related hospitalizations in Italy during the specified period.

Methods

Hospital discharge abstract data for measles hospitalizations in Italy during 2002–2003 were analysed to obtain information regarding number and rates of measles hospitalizations by geographical area and age group, length of hospital stay, and complications. Hospitalization costs were estimated on the basis of Diagnosis-Related Groups.

Results

A total of 5,154 hospitalizations were identified, 3,478 (67%) of which occurred in children <15 years of age. Most hospitalizations occurred in southern Italy (71 %) and children below 1 year of age presented the greatest hospitalization rates (46.2/100,000 and 19.0/100,000, respectively in 2002 and 2003). Pneumonia was diagnosed in 594 cases (11.5%) and encephalitis in 138 cases (2.7%). Total hospital charges were approximately € 8.8 million.

Conclusion

The nationwide health burden associated with measles during the 2002–2003 outbreak was substantial and a high cost was incurred by the Italian National Health Service for the thousands of measles-related hospitalizations which occurred. By assuming that hospital costs represent 40–50% of the direct costs of measles cases, direct costs of measles for the two years combined were estimated to be between €17.6 – 22.0 million, which equates to the vaccination of 1.5–1.9 million children (3–4 birth cohorts) with one dose of MMR. The high cost of measles and the severity of its complications fully justify the commitment required to reach measles elimination.