Incidence of Measles in the United States, 2001-2015

Breakthrough Measles among Vaccinated Adults Born during the Post-Soviet Transition Period in Mongolia

Mongolia experienced a nationwide measles outbreak during 1 March 2015-31 December 2016, with 49,077 cases reported to the WHO; many were among vaccinated young adults, suggesting a possible role of vaccine failure. Advanced laboratory methods, coupled with detailed epidemiological investigations, can help classify cases as vaccine failure, failure to vaccinate, or both. In this report, we conducted a study of cases to identify risk factors for breakthrough infection for a subset of laboratory-confirmed measles cases. Of the 193 cases analyzed, only 19 (9.8%) reported measles vaccination history, and 170 (88%) were uncertain. Measles-specific IgG avidity testing classified 120 (62%) cases as low IgG avidity, indicating no prior exposure to measles. Ten of these cases with low IgG avidity had a history of measles vaccination, indicating primary vaccine failure. Overall, sixty cases (31%) had high IgG avidity, indicating breakthrough infection after prior exposure to measles antigen through vaccination or natural infection, but the IgG avidity results were highly age-dependent. This study found that among young children aged 9 months-5 years, breakthrough infection was rare (4/82, 5%); however, among young adults aged 15-25 years, breakthrough infection due to secondary vaccine failure (SVF) occurred on a large scale during this outbreak, accounting for the majority of cases (42/69 cases, 61%). The study found that large-scale secondary vaccine failure occurred in Mongolia, which highlights the potential for sustained outbreaks in post-elimination settings due to "hidden" cohorts of young adults who may have experienced waning immunity. This phenomenon may have implications for the sustainability of measles elimination in countries that remain vulnerable to the importation of the virus from areas where it is still endemic. Until global measles elimination is achieved, enhanced surveillance and preparedness for future outbreaks in post- or peri-elimination countries may be required.

Measles and Rubella Diagnostic and Classification Challenges in Near- and Post-Elimination Countries

Measles and rubella are vaccine-preventable viral diseases and can be prevented by safe, highly effective vaccination with measles- and rubella-containing vaccines. Given the myriad causes of febrile exanthems, laboratory surveillance for both measles and rubella is important to document the incidence of these diseases and to track the progress and maintenance of elimination in near- and post-elimination settings. Diagnostic challenges can hinder effective surveillance and classification challenges can hinder efforts to demonstrate achievement or maintenance of elimination. In this report, we review diagnostic and classification challenges for measles and rubella in near- and post-elimination settings.

Association of arsenic exposure with measles antibody titers in US children: Influence of sex and serum folate levels

Exposure to arsenic during childhood is associated with various adverse health conditions. However, little is known about the effect of arsenic exposure on vaccine-related humoral immunity in children. We analyzed data from the National Health and Nutrition Examination Survey (2003-2004 and 2009-2010) to study the relationship between urinary arsenic and measles antibody levels in 476 US children aged 6-11. Multivariable linear regression was used to evaluate the association, adjusting for cycle, age, race, body mass index (BMI), serum cotinine, poverty index ratio, and vitamin B12 and selenium intakes. Stratified analyses were conducted by sex and serum folate levels using the median as cutoff (18.7 ng/mL). The measles antibody concentrations in the 3rd and 4th quartiles were found to have significantly decreased by 28.5 % (95 % Confidence Interval (CI) -47.6, -2.28) and 36.8 % (95 % CI -50.2, -19.5), compared to the lowest quartile among boys with serum folate levels lower than 18.7 ng/ml. The serum measles antibody titers significantly decreased by 16.7 % (95 %CI -25.0, -7.61) for each doubling of creatinine-corrected urinary total inorganic arsenic concentrations in the same group. No associations were found in boys with high serum folate levels or in girls. Further prospective studies are needed to validate these findings and develop interventions to protect children from infectious diseases.

Measles: Contemporary considerations for the emergency physician

Measles, or rubeola, is a highly contagious acute febrile viral illness. Despite the availability of an effective vaccine since 1963, measles outbreaks continue worldwide. This article seeks to provide emergency physicians with the contemporary knowledge required to rapidly diagnose potential measles cases and bolster public health measures to reduce ongoing transmission.

Compulsory vaccination against COVID-19: a legal and ethical perspective on public good versus personal reticence

Coercive measures to protect public health are controversial, eliciting questions regarding state-patient relationships and conflicts between individual autonomy and public good. This is challenging in a time when respect for patient autonomy has become elevated yet society faces an increasing number of public health challenges, the most recent being the SARS-CoV-2 virus (COVID-19). In that context, there is emphasis on increasing vaccination rates internationally in order to achieve "herd immunity", raising the possibility of compulsory vaccination of populations in the future. Here, we explore current rights of individuals to decline vaccination, utilising prior learning from other viral pathogens internationally (specifically, measles, mumps and rubella), and related public health outcomes. Further, we consider freedom of choice versus mandatory treatment necessitated to avoid contagion during disease outbreaks (such as COVID-19). In doing so, we utilise rhetorical reasoning in the form of casuistry focusing on the core challenges regarding public good versus personal antipathy towards vaccination.

Incidence in pharmacoepidemiology-Basic definitions and types of misclassification

The definition of a new case is a vital step in incidence studies in both epidemiology and pharmacoepidemiology, although with significant differences in methodology between the fields. We define and apply a framework for two different types of new cases of drug use, first‐ever and recurrent, and show how the associated misclassifications related to length of run‐in period can be expressed by the positive predictive value (PPV).

In the study, we consider individual‐level dispensations of statins 2006–2019 for 1,017,058 individuals with at least one dispensation in 2019 in Sweden. The incidence proportion for statins for both sexes of all ages in Sweden 2019 varied from 17.4/1000 with a run‐in of 8 months, 9.45/1000 with 5 years and 8.4/1000 with 10 years. The PPV was 49% with 8 months and 89% for 5 years using 10 years as gold standard.

We conclude that the interpretation of incidence and thus the selection of an appropriate run‐in period, in pharmacoepidemiology, depends on whether first‐ever use, recurrent treatment or both together (new cases) is the focus of the research question studied. At least five different misclassifications can be introduced depending on how incidence is defined.

Effects of the age of vaccination on the humoral responses to a human papillomavirus vaccine

Adult vaccination programs are receiving increasing attention however, little is known regarding the impact of age on the maintenance of the immune response. We investigated this issue in the context of a human papillomavirus (HPV) vaccination program collecting real-world data on the durability of humoral immunity in 315 female subjects stratified according to vaccination age (adolescents and adults) and sampled at early or late time points after the last vaccine dose. HPV-specific IgGs, but not memory B cells, were induced and maintained at higher levels in subjects vaccinated during adolescence. Nonetheless, antibody functions waned over time to a similar degree in adolescents and adults. To shed light on this phenomena, we analyzed quantitative and qualitative properties of lymphocytes. Similar biochemical features were observed between B-cell subsets from individuals belonging to the two age groups. Long term humoral responses toward vaccines administered at an earlier age were comparably maintained between adolescents and adults. The percentages of naïve B and CD4⁺ T cells were significantly higher in adolescents, and the latter directly correlated with IgG titers against 3 out of 4 HPV types. Our results indicate that age-specific HPV vaccine responsiveness is mostly due to quantitative differences of immune cell precursors rather than qualitative defects in B cells. In addition, our results indicate that adults also have a good humoral immunogenic profile, suggesting that their inclusion in catch-up programmes is desirable.

Maintenance of measles elimination status in the United States for 20 years despite increasing challenges

BACKGROUND

Measles elimination (interruption of endemic measles virus transmission) in the United States was declared in 2000; however, the number of cases and outbreaks have increased in recent years. We characterized the epidemiology of measles outbreaks and measles transmission patterns post-elimination to identify potential gaps in the U.S. measles control program.

METHODS

We analyzed national measles notification data from January 1, 2001-December 31, 2019. We defined measles infection clusters as single cases (isolated cases not linked to additional cases), 2-case clusters, or outbreaks with 3 or more linked cases. We calculated the effective reproduction number (R) to assess changes in transmissibility and reviewed molecular epidemiology data.

RESULTS

During 2001-2019, 3,873 measles cases, including 747 international importations, were reported in the United States; 29% of importations were associated with outbreaks. Among 871 clusters, 69% were single cases and 72% had no spread. Larger and longer clusters were reported since 2013, including seven outbreaks with >50 cases lasting >2 months, 5 of which occurred in known underimmunized, close-knit communities. No measles lineage circulated in a single transmission chain for >12 months. Higher estimates of R were noted in recent years, although R remained below the epidemic threshold of 1.

CONCLUSIONS

Current epidemiology continues to support the interruption of endemic measles virus transmission in the United States. However, larger and longer outbreaks in recent post-elimination years and emerging trends of increased transmission in underimmunized communities emphasize the need for targeted approaches to close existing immunity gaps and maintain measles elimination.

Quality improvement project to improve vaccinations in the pediatric liver transplant population

OBJECTIVES

A quality improvement approach was used to increase pediatric liver transplant recipient live and inactive vaccination rates by assessing titers and recommending vaccinations.

METHODS

A new screening and immunization process for both live and inactive vaccines was discussed with families at their annual visit. Antibody titers for varicella, measles, mumps, rubella, Haemophilus influenzae type B, hepatitis A, and hepatitis B were obtained. Specific criteria were developed for live virus vaccination candidacy. Vaccines were recommended based on patient titers and vaccination candidacy criteria. Surveillance for adverse effects to live vaccines was performed. Repeat titers were obtained approximately 1-month post-vaccine administration.

RESULTS

After PDSA cycle 1, 99% (71/72) of pediatric liver transplant patients had titers obtained. Live vaccines were recommended for 32 patients and 16 (50%) were vaccinated. Inactive vaccines were recommended to 64 patients, and 31 (48%) were vaccinated. Eight of 13 (62%) patients with follow-up titers achieved immunity for inactive vaccines. Zero patients had an adverse reaction to any live vaccine. Ten of 12 (83%) patients with follow-up titers achieved immunity from live vaccines. The most common barriers to receive live vaccines included not scheduling appointment with primary care provider (n = 3) and "non-vaccinators" (n = 3).

CONCLUSIONS

Administering live and inactive vaccines to select pediatric liver transplant patients appears to be safe and effective in our studied population. For PDSA cycle 2, we will continue our current practice and consider offering vaccines in transplant clinic, since this was a barrier to vaccination identified during PDSA cycle 1.

COVID-19 vaccine acceptance: influential roles of political party and religiosity

Given recent declines in US vaccination rates and the emergence of COVID-19 vaccines, identifying sociodemographic influencers of vaccine willingness holds importance for developing effective public health campaigns aimed at enhancing nationwide COVID-19 vaccine acceptance. The present study utilized a hierarchical binary logistic regression model to assess demographic variables (age, gender, race/ethnicity, pre-existing medical conditions), political party membership, religious affiliation, level of religiosity, and fear of COVID-19 as predictors of COVID-19 vaccine acceptance ('Yes', would receive a vaccine or 'No', would not receive a vaccine) in a national sample of US adults (N = 249). Participants were recruited from Amazon's Mechanical Turk (MTurk) and completed several online questionnaires pertaining to mental health, health behaviors, and responses to the COVID-19 pandemic. Both Democratic party membership and decreased level of religiosity predicted acceptance of a COVID-19 vaccine. This investigation supports political party membership and religiosity as influencers of COVID-19 vaccine willingness and suggests that these variables could represent potential targets for public health interventions aimed at increasing vaccine adoption.

Gender Differences in the Level of Antibodies to Measles Virus in Adults

Individuals without a protective antibody level are susceptible to measles infection. There are differences in the persistence of antibodies after vaccination and infection, while the impact of gender on this process has not been sufficiently studied. Measles Ig G antibodies were measured in 1742 employees of a large hospital facility-403 men and 1339 women aged from 25 to 67 years; 15% participants had antibody levels less than the protective threshold of ≥0.18 IU/mL. Significant differences were found in the age group 40-49, where the level of IgG antibodies to measles among men was higher than among women (1.51 IU/mL (0.41; 3.38) vs. 0.70 IU/mL (0.22;1.98) respectively, (U = 3.2, p = 0,001)); in the age group 60 and older, by contrast, the level of antibodies among women was higher compared to men (3.29 IU/mL (1.72; 4.07) vs. 2.90 IU/mL (1.46; 3.53) respectively (U = 2.2, p = 0.03)). The proportion of seronegative women in the age group 40-49 was significantly higher than of seronegative men: 22 [18-26]% and 11 [6-18]% respectively (χ2 = 7.0, p = 0.001). The revealed gender characteristics that affect persistence of measles immunity may be important in personalization of vaccinal prevention for men and women.

Identifying Vaccine-associated Rash Illness Amidst a Large Measles Outbreak: Minnesota, 2017

Characteristics of vaccine-associated rash illness (VARI) and confirmed measles cases were compared during a measles outbreak. Although some clinical differences were noted, measles exposure and identification of the vaccine strain were helpful for public health decision-making. Rapid, vaccine strain-specific diagnostic assays will more efficiently distinguish VARI from measles.

How adequate is measles surveillance in the United States? Investigations of measles-like illness, 2010-2017

Given the availability of an effective and safe vaccine, the World Health Organization (WHO) declared that global measles eradication is achievable, and measles elimination goals have since been established as interim steps toward eradication. As part of a strategy to maintain elimination, the Pan American Health Organization (PAHO) and WHO stipulate a minimum annual reporting rate of discarded non-measles cases of ≥2 per 100,000 population, in order to ensure sensitive surveillance and adequate investigative effort. With its effective vaccination program, the United States in 2000 was among the first countries to verify elimination, although subsequently, it has not routinely reported discarded rates. We estimated MLI investigation rates among insured individuals during 2010-2017, using data from the MarketScan® databases. We defined "MLI investigations" as measles serologic testing within 5 days following diagnostic codes for measles-compatible symptoms and conditions. We provide a rationale for pre-specifying three subgroups for analysis: children aged ≤15 years; males aged 16-22 years excluding data from summer months; and males aged ≥23 years. MLI investigation rates ranged from 6.6─26.4 per 100,000, remaining stable over time except during the 2015 measles outbreaks when rates increased, particularly among young children. In addition to high vaccine uptake, measles elimination requires ongoing vigilance by clinicians and high-quality, case-based surveillance. Estimated rates of MLI investigations in this U.S. population suggesting that the quality of measles surveillance is sufficiently sensitive to detect endemic measles circulation if it were to be occurring.

Factors associated with measles resurgence in the United States in the post-elimination era

There have been growing concerns of a potential re-establishment of measles transmission in the United States (US) in the years to come. This study aims to explore potential factors underlying the resurgence of measles in the US by objectively assessing the associations between annual incidence rates (AIR), case importation, vaccination status and disease outbreaks. Data on measles transmission between January 1st, 2001 and December 31st, 2019 were obtained from the national centres for disease control and prevention (CDC) surveillance databases and other published reports. Changes in incidence rates over time were assessed by binomial regression models. Of the 3874 cases of measles in the US over the study period, 3506 (90.5%, 95% CI: 89.5-91.4) occurred in US residents. The AIR per million population in US residents over this period was 0.60 (95% CI: 0.59-0.61), with an overall significant increase over time (p = 0.011). The median percentage of imported and vaccinated cases were 36% [17.9-46.6] and 15% [12.1-23.2] respectively. There was a significant decrease in the percentage of imported cases (p < 0.001) but not of vaccinated cases (p = 0.159) over time. There was a moderate and weak negative correlation between the AIR and the percentage of imported and vaccinated cases respectively (r = -0.59 and r = -0.27 respectively). On multiple linear regression there was a significant linear association between the AIR and the number of outbreaks (p = 0.003) but not with the percentage of imported cases (p = 0.436) and vaccinated cases (p = 0.692), R2 = 0.73. Strong negative and positive correlations were seen between the number of outbreaks and the percentage of imported cases (r = -0.61) and the of number states affected (r = 0.88) respectively. Despite the overall reduction in the percentage of imported cases of measles over the past two decades, pockets of internal transmission of the disease following importation via increasing number of outbreaks in unvaccinated subpopulations, reinforced by vaccine hesitancy, account for the sustained increase in measles incidence rates in the US. Controlling indigenous transmission through efficient vaccination coverage in at-risk subpopulations and among international US travellers, improved disease surveillance and rapid outbreak containment are essential in curbing the measles resurgence.

The Importance of Prioritizing Pre and Posttransplant Immunizations in an Era of Vaccine Refusal and Epidemic Outbreaks

Vaccine-preventable infections are occurring at epidemic rates both nationally and internationally. At the same time, rates of vaccine hesitancy and refusal are increasing across the country leading to decreased herd immunity. For immunosuppressed transplant recipients, this situation poses great risk. Currently, 1 in 6 pediatric solid organ transplant recipients is hospitalized with a vaccine-preventable infection in the first 5 years posttransplant. For many recipients, these infections result in significant morbidity, mortality, and increased hospitalization costs. Surprisingly, despite this risk many transplant recipients are not up-to-date on age appropriate immunizations at the time of transplant and thereafter. As a transplant community, we must prioritize immunizations in both pre and posttransplant care. Research is needed to understand how to monitor immune response to vaccines in immunosuppressed patients and when to optimally immunize patients posttransplant. Finally, recommendations about administration of live vaccines posttransplant may need to be reevaluated in the setting of measles outbreaks and decreased herd immunity.

A Review of Measles Outbreak Cost Estimates From the United States in the Postelimination Era (2004-2017): Estimates by Perspective and Cost Type

Despite the elimination of measles in the United States (US) in the year 2000, cases continue to occur, with measles outbreaks having occurred in various jurisdictions in the US in 2018 and 2019. Understanding the cost associated with measles outbreaks can inform cost-of-illness and cost-effectiveness studies of measles and measles prevention. We performed a literature review and identified 10 published studies from 2001 through 2018 that presented cost estimates from 11 measles outbreaks. The median total cost per measles outbreak was $152 308 (range, $9862-$1 063 936); the median cost per case was $32 805 (range, $7396-$76 154) and the median cost per contact was $223 (range, $81-$746). There were limited data on direct and indirect costs associated with measles. These findings highlight how costly measles outbreaks can be, the value of this information for public health department budgeting, and the importance of more broadly documenting the cost of measles outbreaks.

The Importance of MMR Immunization in the United States

Despite the established safety and efficacy of the measles-mumps-rubella vaccine after almost 50 years of widespread use, the United States is encountering higher levels of measles and mumps disease than has occurred for years. Return of disease threatens the health of those who remain unimmunized by choice as well as those who are immunized appropriately but experience loss of vaccine-induced immunity. The solution to continued threats of illness caused by these untreatable but readily preventable diseases is compliance with recommendations for administration of the measles-mumps-rubella vaccine. Here we examine trends in the epidemiology of measles, mumps, and rubella in recent years and consider the consequences of loss of protective immunity within our country.

The Clinical Impact and Cost-effectiveness of Measles-Mumps-Rubella Vaccination to Prevent Measles Importations Among International Travelers From the United States

BACKGROUND

Measles importations and the subsequent spread from US travelers returning from abroad are responsible for most measles cases in the United States. Increasing measles-mumps-rubella (MMR) vaccination among departing US travelers could reduce the clinical impact and costs of measles in the United States.

METHODS

We designed a decision tree to evaluate MMR vaccination at a pretravel health encounter (PHE), compared with no encounter. We derived input parameters from Global TravEpiNet data and literature. We quantified Riskexposure to measles while traveling and the average number of US-acquired cases and contacts due to a measles importation. In sensitivity analyses, we examined the impact of destination-specific Riskexposure, including hot spots with active measles outbreaks; the percentage of previously-unvaccinated travelers; and the percentage of travelers returning to US communities with heterogeneous MMR coverage.

RESULTS

The no-encounter strategy projected 22 imported and 66 US-acquired measles cases, costing $14.8M per 10M travelers. The PHE strategy projected 15 imported and 35 US-acquired cases at $190.3M per 10M travelers. PHE was not cost effective for all international travelers (incremental cost-effectiveness ratio [ICER] $4.6M/measles case averted), but offered better value (ICER <$100 000/measles case averted) or was even cost saving for travelers to hot spots, especially if travelers were previously unvaccinated or returning to US communities with heterogeneous MMR coverage.

CONCLUSIONS

PHEs that improve MMR vaccination among US international travelers could reduce measles cases, but are costly. The best value is for travelers with a high likelihood of measles exposure, especially if the travelers are previously unvaccinated or will return to US communities with heterogeneous MMR coverage.

Inpatient morbidity and mortality of measles in the United States

Background

Measles is an extremely contagious, vaccine-preventable infection that was officially declared eradicated in the US in 2000. However, measles outbreaks are increasingly occurring in the US. Measles cases have considerable morbidity requiring hospitalization, yet little is known about hospitalization and complications from measles in recent years.

Objectives

To analyze the frequency, predictors, costs and other outcomes of hospitalization for measles in the US.

Methods

The 2002–2016 Nationwide Inpatient Sample, containing a 20% sample of US hospitalizations (n = 96,568,625), was analyzed. Measles and comorbidities were defined by International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) or ICD-10-CM codes. Multivariable survey logistic regression and linear regression models controlling for sociodemographic demographic factors were constructed to understand associations with organ-specific complications, and cost of care and length of stay, respectively.

Results

Overall, 1,018 measles hospitalizations occurred in 2002–2016, and hospitalizations increased over time. In multivariable logistic regression models, measles was associated with higher odds of gastrointestinal, hematologic, infectious, neurologic, ophthalmologic, pulmonary, and renal complications, with the strongest association observed with encephalitis (39.84 [16.51–96.12], P<0.0001). Increased length of stay (LOS) and similar cost of care (mean [95% CI]; 4.8 [4.4–5.4]; $7,438 [$6,446-$8,582]) were observed versus (vs.) all other admissions (4.5 [4.4–4.5]; P<0.01; $7,854 [$7,774-$7,935], P>0.05). There were 34 deaths in hospitalized measles patients; inpatient mortality was numerically higher in those with vs. without measles (proportion ± SEM: 3.3±1.2% vs. 2.3±0.01%, P = 0.333).

Limitations

Lack of outpatient or prescription data.

Conclusions

Measles continues to pose a substantial and preventable health care burden, with serious complications, hospitalization and inpatient mortality. Further studies are needed to improve the prevention and management of measles.

Conscientious vaccination exemptions in kindergarten to eighth-grade children across Texas schools from 2012 to 2018: A regression analysis

BACKGROUND

As conscientious vaccination exemption (CVE) percentages rise across the United States, so does the risk and occurrence of outbreaks of vaccine-preventable diseases such as measles. In the state of Texas, the median CVE percentage across school systems more than doubled between 2012 and 2018. During this period, the proportion of schools surpassing a CVE percentage of 3% rose from 2% to 6% for public schools, 20% to 26% for private schools, and 17% to 22% for charter schools. The aim of this study was to investigate this phenomenon at a fine scale.

METHODS AND FINDINGS

Here, we use beta regression models to study the socioeconomic and geographic drivers of CVE trends in Texas. Using annual counts of CVEs at the school system level from the 2012-2013 to the 2017-2018 school year, we identified county-level predictors of median CVE percentage among public, private, and charter schools, the proportion of schools below a high-risk threshold for vaccination coverage, and five-year trends in CVEs. Since the 2012-2013 school year, CVE percentages have increased in 41 out of 46 counties in the top 10 metropolitan areas of Texas. We find that 77.6% of the variation in CVE percentages across metropolitan counties is explained by median income, the proportion of the population that holds a bachelor's degree, the proportion of the population that self-reports as ethnically white, the proportion of the population that is English speaking, and the proportion of the population that is under the age of five years old. Across the 10 top metropolitan areas in Texas, counties vary considerably in the proportion of school systems reporting CVE percentages above 3%. Sixty-six percent of that variation is explained by the proportion of the population that holds a bachelor's degree and the proportion of the population affiliated with a religious congregation. Three of the largest metropolitan areas-Austin, Dallas-Fort Worth, and Houston-are potential vaccination exemption "hotspots," with over 13% of local school systems above this risk threshold. The major limitations of this study are inconsistent school-system-level CVE reporting during the study period and a lack of geographic and socioeconomic data for individual private schools.

CONCLUSIONS

In this study, we have identified high-risk communities that are typically obscured in county-level risk assessments and found that public schools, like private schools, are exhibiting predictable increases in vaccination exemption percentages. As public health agencies confront the reemerging threat of measles and other vaccine-preventable diseases, findings such as ours can guide targeted interventions and surveillance within schools, cities, counties, and sociodemographic subgroups.

Epidemiology and features of the measles course in children during the outbreak of 2018–2019 in the city of Mariupol

In 2017, Ukraine ranked in the top three among European countries in terms of measles incidence, and ranked first in measles growth in 2018. High morbidity, mortality and development of complications make the problem of knowing features of the measles clinical course, timely diagnosis and active prevention highly relevant. The purpose of the research is to study the dynamics of the incidence and clinical features of measles in children during the outbreak of 2018–2019 in the city of Mariupol, Donetsk region. A peculiarity of the measles outbreak in 2018–2019 in Mariupol is prevalence of the disease in preschool children (60.4%), inclu­ding 30.2% – those under one year of age; low vaccination rate: 52.3% of children unvaccinated; only 22.2% of children were vaccinated twice, according to the schedule. In all age groups, a moderately severe measles course prevailed (69.8%). The clinical course of measles in preschool and school age children had definitive features. Thus, Belsky–Filatov–Koplik spots were observed three times more frequently in preschool children than in schoolchildren (63.9% and 23.3%, respectively). Abdominal pain and diarrhea were only observed in children under 6 years of age (30.2%). Skin pigmentation was absent in children under one year of age and was detected in preschool and school-age children (69.8%). Skin sloughing was only observed in schoolchildren (10.4%). Severe disease course occurred in patients of all ages (29.3%), but children aged under one year and preschool children with severe disease were two times more numerous than those of the school age. Among the observed complications, the vast majority were associated with the respiratory organs: pneumonia (38.3%), subcutaneous emphysema (1.7%), bronchitis (53.2%), laryngitis (3.3%), otitis media (5%). No fatalities were observed. The city should form a commitment to immunization, restore public trust in vaccination, using all forms and means of information, and develop a program to implement the vaccination schedule into practice.

Measles transmission during a large outbreak in California

A large measles outbreak in 2014–2015, linked to Disneyland theme parks, attracted international attention, and led to changes in California vaccine policy. We use dates of symptom onset and known epidemic links for California cases in this outbreak to estimate time-varying transmission in the outbreak, and to estimate generation membership of cases probabilistically. We find that transmission declined significantly during the course of the outbreak (p = 0.012), despite also finding that estimates of transmission rate by day or by generation can overestimate temporal decline. We additionally find that the outbreak size and duration alone are sufficient in this case to distinguish temporal decline from time-invariant transmission (p = 0.014). As use of a single large outbreak can lead to underestimates of immunity, however, we urge caution in interpretation of quantities estimated from this outbreak alone. Further research is needed to distinguish causes of temporal decline in transmission rates.

A Survey of Vaccine-Induced Measles IgG Antibody Titer to Verify Temporal Changes in Response to Measles Vaccination in Young Adults

In Japan, sporadic measles cases increased rapidly in 2019 compared to the past six years. To clarify the persistence of immunity against measles in young adults, this study explored the persistence of immunoglobulin G (IgG) antibody titers against the measles virus in 17- to 24-year-old young participants who reside in the Chiba prefecture of Japan. Measles-specific IgG antibody titers, determined by enzyme immunoassay in serum samples collected from 506 participants, were assessed through statistical analyses. Multivariable regression analysis revealed that the distribution of measles IgG antibody titers was significantly correlated with a medical history of measles (P < 0.05), while there was no significant correlation between the number of vaccinations related to measles IgG titers. Furthermore, measles IgG titers tended to decrease, as revealed by the temporal change in IgG titers, during the elapsed period after the last vaccination (P = 0.08). These results indicate that periodic vaccination against measles is required to prevent sporadic measles infection in young and older adults.

Spread of Measles in Europe and Implications for US Travelers

From January 2018 to June 2018, World Health Organization (WHO) European Region countries reported >41 000 measles cases, including 37 deaths, a record high since the 1990s. Low vaccination coverage in previous years is the biggest contributing factor to the increase in cases. The Ukraine reported the majority of cases, but France, Georgia, Greece, Italy, the Russian Federation, and Serbia also reported high case counts. Europe is the most common travel destination worldwide and is widely perceived as being without substantial infectious disease risks. For this reason, travelers may not consider the relevance of a pretravel health consultation, including vaccination, in their predeparture plans. Measles is highly contagious, and the record number of measles cases in the WHO European Region not only puts unvaccinated and inadequately vaccinated travelers at risk but also increases the risk for nontraveling US residents who come into close contact with returned travelers who are ill. The US Centers for Disease Control and Prevention encourage US travelers to be aware of measles virus transmission in Europe and receive all recommended vaccinations, including for measles, before traveling abroad. Health care providers must maintain a high degree of suspicion for measles among travelers returning from Europe or people with close contact with international travelers who present with a febrile rash illness. The current WHO European Region outbreak should serve to remind health care providers to stay current with the epidemiology of highly transmissible diseases, such as measles, through media, WHO, and Centers for Disease Control and Prevention reports and encourage measles vaccination for international travelers.

Measles Hospitalizations at a United States Children's Hospital 2011-2017

BACKGROUND

There are no recent descriptions of measles hospitalizations and complications in US children despite outbreaks within the past decade-including 2 in Minnesota (2011 and 2017). The objective of our study was to describe complications, hospital management and resource utilization for children hospitalized for measles at a US children's hospital.

METHODS

Retrospective case series of children (0-18 years of age) hospitalized for measles (observation/inpatient diagnosis code for measles) at Children's Minnesota, January 1, 2011, to September 1, 2017. Descriptive statistics were performed.

RESULTS

Thirty-three patients were included (7 from 2011 and 21 from 2017 outbreaks). Median age was 27 months (range, 6-95 months), 94% were Black or African American (73% Somali ethnicity), 88% had medical assistance and 91% were unvaccinated to measles. Poor feeding was a primary reason for admission (97%); additional complications included otitis media (42%), pneumonia (30%), tracheitis (6%) and keratitis (3%). Additional testing was common [chest radiographs (70%), blood cultures (64%), nonmeasles viral testing (42%)]. Seventy-three percent received antibiotics, 30% required oxygen and 21% received vitamin A. Median length of stay was 3.7 days (range, 1.1-26.2 days); 1 patient was readmitted. Median direct cost in 2017 was $5291 (interquartile range : $3907-$7519), and estimated total cost to the hospital for the 2017 outbreak was $1.3 million.

CONCLUSIONS

Clinicians should be aware of measles complications and treatment. Public and private health efforts should continue to focus on immunization, given significant implications of measles infections for patients and healthcare systems. Future studies may assess complications of measles across the United States as individual outbreaks often occur in specific populations, making generalization of results challenging.

Increase in Measles Cases - United States, January 1-April 26, 2019

As of April 26, 2019, CDC had reported 704 cases of measles in the United States since the beginning of 2019, representing the largest number of cases reported in the country in a single year since 1994, when 963 cases occurred, and since measles was declared eliminated* in 2000 (1,2). Measles is a highly contagious, acute viral illness characterized by fever and a maculopapular rash; complications include pneumonia, encephalitis, and death. Among the 704 cases, 503 (71%) were in unvaccinated persons and 689 (98%) occurred in U.S. residents. Overall, 66 (9%) patients were hospitalized. Thirteen outbreaks have been reported in 2019, accounting for 663 cases, 94% of all reported cases. Six of the 13 outbreaks were associated with underimmunized close-knit communities and accounted for 88% of all cases. High 2-dose measles vaccination coverage in the United States has been critical to limiting transmission (3). However, increased global measles activity poses a risk to U.S. elimination, particularly when unvaccinated travelers acquire measles abroad and return to communities with low vaccination rates (4). Health care providers should ensure persons are up to date with measles, mumps, rubella (MMR) vaccine, including before international travel, and rapidly report all suspected cases of measles to public health authorities.

Successes and challenges for preventing measles, mumps and rubella by vaccination

The measles, mumps and rubella (MMR) vaccine has an outstanding safety record and is highly efficacious. High coverage with MMR has led to the elimination of endemic measles, rubella, and congenital rubella syndrome in the US. The biggest challenges to global measles and rubella control and elimination are insufficient vaccination coverage globally and increasing hesitancy. Despite high two dose coverage rates, mumps has made a resurgence in the US and other countries. Mumps outbreaks have occurred primarily in close contact, high-density settings and most cases had received a second dose 10 or more years previously. Waning humoral immunity and antigenic variation of circulating wild-type mumps strains may play a role in the mumps resurgence.

Vaccination Practices Among Obstetrician/Gynecologists for Non-pregnant Patients

INTRODUCTION

Many non-pregnant women see obstetrician-gynecologists as their sole source of medical care, yet little is known about vaccination practices of obstetrician-gynecologists for non-pregnant patients. The objectives were to assess, among a national sample of obstetrician-gynecologists, practices related to vaccine delivery in non-pregnant patients and factors associated with stocking and administering more than three different vaccines to non-pregnant patients.

METHODS

E-mail and mail surveys were administered July-October 2015, with analyses performed during October-November 2015 and April-June 2018.

RESULTS

The response rate was 73% (353/482). Human papillomavirus (92%); influenza (82%); and tetanus, diphtheria, acellular pertussis vaccines (50%) were the vaccines most commonly assessed, with the remaining vaccines assessed by <40% of respondents. Vaccines most commonly administered by obstetrician-gynecologists to non-pregnant patients included human papillomavirus (81%); influenza (70%); and tetanus, diphtheria, acellular pertussis (54%). The remaining vaccines were administered by <30% of obstetrician-gynecologists. Factors associated with routinely administering more than three vaccines to non-pregnant patients included working in a hospital-, public health-, or university-associated clinic (RR=1.87, 95% CI=1.35, 2.58, referent to private practice); a larger practice (more than five providers; RR=1.54, 95% CI=1.05, 2.27); perceiving fewer financial barriers (RR=0.74, 95% CI=0.57, 0.96); fewer practice-associated barriers (RR=0.71, 95% CI=0.55, 0.92); and greater patient barriers (RR=1.62, 95% CI=1.33, 1.98).

CONCLUSIONS

Human papillomavirus; influenza; and tetanus, diphtheria, acellular pertussis vaccines are the only vaccines routinely assessed and administered to non-pregnant patients by most obstetrician-gynecologists. Given their role as the sole source of care for many women, obstetrician-gynecologists could make a positive impact on the vaccination status of their non-pregnant patients.

Is There a Resurgence of Vaccine Preventable Diseases in the U.S.?

Immunizations are a safe and effective means of promoting health and preventing disease. Vaccine programs prevent millions of cases of disease and save thousands of lives in the U.S. each year; however, the threat of vaccine-preventable diseases remains. Recent years have seen a resurgence in certain vaccine-preventable diseases which can be attributed to vaccine refusals, under-vaccination, waning immunity, less effective immunizations, and imported cases. Nurses must stay informed about the current state of vaccine compliance and disease resurgence in order to best educate families. Understanding why families refuse or delay vaccinations provides a basis for nurses to plan educational interventions designed to best meet the needs of each family.

Current perspectives in assessing humoral immunity after measles vaccination

INTRODUCTION

Repeated measles outbreaks in countries with relatively high vaccine coverage are mainly due to failure to vaccinate and importation; however, cases in immunized individuals exist raising questions about suboptimal measles vaccine-induced humoral immunity and/or waning immunity in a low measles-exposure environment.

AREAS COVERED

The plaque reduction neutralization measurement of functional measles-specific antibodies correlates with protection is the gold standard in measles serology, but it does not assess cellular-immune or other parameters that may be associated with durable and/or protective immunity after vaccination. Additional correlates of protection and long-term immunity and new determinants/signatures of vaccine responsiveness such as specific CD46 and IFI44L genetic variants associated with neutralizing antibody titers after measles vaccination are under investigation. Current and future systems biology studies, coupled with new technology/assays and analytical approaches, will lead to an increasingly sophisticated understanding of measles vaccine-induced humoral immunity and will identify 'signatures' of protective and durable immune responses.

EXPERT OPINION

This will translate into the development of highly predictive assays of measles vaccine efficacy, effectiveness, and durability for prospective identification of potential low/non-responders and susceptible individuals who require additional vaccine doses. Such new advances may drive insights into the development of new/improved vaccine formulations and delivery systems.

Public health responses during measles outbreaks in elimination settings: Strategies and challenges

In late September 2016, the Americas became the first region in the world to have eliminated endemic transmission of measles virus. Several other countries have also verified measles elimination, and countries in all six World Health Organization regions have adopted measles elimination goals. The public health strategies used to respond to measles outbreaks in elimination settings are thus becoming relevant to more countries. This review highlights the strategies used to limit measles spread in elimination settings: (1) assembly of an outbreak control committee; (2) isolation of measles cases while infectious; (3) exclusion and quarantining of individuals without evidence of immunity; (4) vaccination of susceptible individuals; (5) use of immunoglobulin to prevent measles in exposed susceptible high-risk persons; (6) and maintaining laboratory proficiency for confirmation of measles. Deciding on the extent of containment efforts should be based on the expected benefit of reactive interventions, balanced against the logistical challenges in implementing them.

Beyond vaccine dosage, genetic modifications to the current measles vaccine to overcome maternal passive immunity

Pediatric measles infections still cause an unacceptable rate of childhood mortality. Despite the availability of an efficient preventative vaccine, measles virus can spread among the population of even developed countries. The availability of a reverse genetic system for measles, based on recombinant virus recovery from cDNA, allows application of the principles of intelligent vaccine design. Using this system, we recently demonstrated that a version of the current attenuated measles virus strain genetically modified to express higher levels of the viral hemagglutinin protein, the major target of neutralizing antibodies, is more immunogenic and resists passive immunity with a better immunogenicity profile in a mouse model than the current measles vaccine. The significance and practicality of this development are discussed.