The Reemergence of Measles

A fractional modeling approach for the transmission dynamics of measles with double-dose vaccination

Measles, a member of the Paramyxoviridae family and the Morbillivirus genus, is an infectious disease caused by the measles virus that is extremely contagious and can be prevented through vaccination. When a person with the measles coughs or sneezes, the virus is disseminated by respiratory droplets. Normally, the appearance of measles symptoms takes 10-14 d following viral exposure. Conjunctivitis, a high temperature, a cough, a runny nose, and a distinctive rash are some of the symptoms. Despite the measles vaccination being available, it is still widespread worldwide. To eradicate measles, the Reproduction Number (i.e. R 0 < 1 ) must remain less than unity. This study examines a SEIVR compartmental model in the caputo sense using a double dose of vaccine to simulate the measles outbreak. The reproduction number R 0 and model properties are both thoroughly examined. Both the local and global stabilities of the proposed model are determined for R 0 less and greater than 1. To achieve the model's global stability, the Lyapunov function is used while the existence and uniqueness of the proposed model are demonstrated In addition to the calculated and fitted biological parameters, the forward sensitivity indices for R 0 are also obtained. Simulations of the proposed fractional order (FO) caputo model are performed in order to analyse their graphical representations and the significance of FO derivatives to illustrate how our theoretical findings have an impact. The graphical results show that the measles outbreak is reduced by increasing vaccine dosage rates.

Measles outbreak investigation in Kasoshekumer kebele, Sinana district, South-Eastern Oromia, Ethiopia: A case-control study

Objective

This study aimed at verifying the outbreak, preventing further transmission, and identifying the risk factors for the outbreak.

Method

A case-control study design was conducted from March 4, 2020 to April 30, 2020, in Kasoshekumer kebele of Sinana district. Thirty-seven carer-patient pairs and 74 controls were recruited in a 1:2 case-control ratio. Patients were selected using a national standard case definition of the Ministry of Health. Controls were selected from neighbors of patients and interviewed after the second incubation period from the last patient of the outbreak by a structured questionnaire similar to patients. All cases were included while controls were selected purposively for their exposure status. Vaccine efficacy, attack rate, and case fatality rate were conducted as a descriptive epidemiology. Multivariate analysis was used to identify associated factors.

Result

Out of 109 study participants, there were 37 cases and 72 controls. The mean age was 58.8 months with ±54 standard deviation. Thirty-one (83.8%) of the cases had a known contact history and 23 (62.2%) were unvaccinated. The age-specific attack rate was 36/1000 in <5 years and 53/100,000 in >15 years. The estimated vaccine efficacy was 73.7%. Having any type of socialization behavior (adjusted odds ratio = 6.8, confidence interval: 4.25, 11.4), maternal poor knowledge of measles prevention (adjusted odds ratio = 4.152, confidence interval: 1.226, 8.058), and being unvaccinated (adjusted odds ratio = 7.79, confidence interval: 2.281, 12.63) were associated factors for measles infection.

Conclusion

Poor knowledge of the parents on vaccination and the less effort taken to deliver good attitude toward vaccination are resulting in measles outbreak. However, herd immunity can prevent the outbreak; if not, the community will continue to suffer from mortality and morbidity. A resilient immunization program with sustainable and equitable supply, delivery, monitoring, and evaluation is a fundamental action in prevention of measles outbreak. Increased awareness of vaccination and other prevention measures are also crucial to end the outbreaks.

Attitudes and Beliefs around the Value of Vaccination in the United States

Despite the benefits of immunization, differences in attitudes persist toward vaccines. We captured individuals’ perceptions of vaccines and vaccination across the United States (US) to inform vaccine-related policy development. A survey was completed by 5000 respondents from 10 states. Respondents were screened for inclusion, which included individuals ≥ 18 years of age that had received a vaccine or were unvaccinated but indicated a favorable or neutral attitude towards vaccinations. Participants were excluded if they indicated they did not support the idea of vaccinations. Questions explored perceptions of vaccines for all age groups. Among unvaccinated individuals, the most common concerns were about safety (38%). Most respondents (95%) highlighted the importance of state immunization programs for disease prevention. Access to health and immunization records and immunization information systems were important to 96% and 88% of respondents, respectively, for future health planning. Doctors and healthcare professionals (HCPs) were considered trusted sources for vaccine information (95%). Overall, respondents recognized the importance of vaccination, but documented concerns among the unvaccinated indicated a need for greater promotion regarding vaccine safety. Doctors and HCPs, as trusted information sources, should continue to and increasingly advocate for the importance of immunization to increase vaccine uptake.

Gaps in measles vaccination coverage in Kasese district, Western Uganda: results of a qualitative evaluation

Background

Despite the availability of a highly effective vaccine, measles remains a substantial public health problem in many countries including Uganda. In this study, conducted between June–August 2020 following a local outbreak, we sought to explore the factors that could affect measles vaccination coverage in rural western Uganda.

Methods

We conducted a descriptive study using qualitative data collection approaches in the Kasese district. The research team utilized purposive sampling to identify and select participants from the public health sector and district government. We conducted key informant interviews (KII) and one focus group discussion (FGD). Responses were recorded using portable electronic devices with the FGD and KII guide installed. Interviews were conducted at the health centre and district headquarters. Data was coded and analysed using ATLAS.ti version 8 software through deductive thematic analysis to identify key themes.

Results

Barriers to measles vaccination identified in this study were premised around six themes including: (i) availability of supplies and stock management, (ii) health worker attitudes and workload, (iii) financing of vaccination outreach activities, (iv) effectiveness of duty rosters (i.e., health workers’ working schedules), (v) community beliefs, and (vi) accessibility of healthcare facilities. Respondents reported frequent vaccine supply disruptions, lack of resources to facilitate transportation of health workers to communities for outreach events, and health centre staffing that did not adequately support supplemental vaccination activities. Furthermore, community dependence on traditional medicine as a substitute for vaccines and long distances traveled by caregivers to reach a health facility were mentioned as barriers to vaccination uptake.

Conclusions

Health system barriers limiting vaccination uptake were primarily logistical in nature and reflect inadequate resourcing of immunization efforts. At the same time, local beliefs favouring traditional medicine remain a persistent cultural barrier. These findings suggest an urgent need for more efficient supply management practices and resourcing of immunization outreaches in order to achieve the Uganda Ministry of Health’s targets for childhood immunization and the prevention of disease outbreaks.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07579-w.

Mathematical analysis of a measles transmission dynamics model in Bangladesh with double dose vaccination

Although the availability of the measles vaccine, it is still epidemic in many countries globally, including Bangladesh. Eradication of measles needs to keep the basic reproduction number less than one \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(\mathrm{i}.\mathrm{e}. \, \, {\mathrm{R}}_{0}<1)$$\end{document}(i.e.R0<1). This paper investigates a modified (SVEIR) measles compartmental model with double dose vaccination in Bangladesh to simulate the measles prevalence. We perform a dynamical analysis of the resulting system and find that the model contains two equilibrium points: a disease-free equilibrium and an endemic equilibrium. The disease will be died out if the basic reproduction number is less than one \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(\mathrm{i}.\mathrm{e}. \, \, {\mathrm{ R}}_{0}<1)$$\end{document}(i.e.R0<1), and if greater than one \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(\mathrm{i}.\mathrm{e}. \, \, {\mathrm{R}}_{0}>1)$$\end{document}(i.e.R0>1) epidemic occurs. While using the Routh-Hurwitz criteria, the equilibria are found to be locally asymptotically stable under the former condition on \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{R}}_{0}$$\end{document}R0. The partial rank correlation coefficients (PRCCs), a global sensitivity analysis method is used to compute \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{R}}_{0}$$\end{document}R0 and measles prevalence \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left({\mathrm{I}}^{*}\right)$$\end{document}I∗ with respect to the estimated and fitted model parameters. We found that the transmission rate \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(\upbeta )$$\end{document}(β) had the most significant influence on measles prevalence. Numerical simulations were carried out to commissions our analytical outcomes. These findings show that how progression rate, transmission rate and double dose vaccination rate affect the dynamics of measles prevalence. The information that we generate from this study may help government and public health professionals in making strategies to deal with the omissions of a measles outbreak and thus control and prevent an epidemic in Bangladesh.

Measles outbreak in Western Uganda: a case-control study

BACKGROUND

Measles outbreaks are prevalent throughout sub-Saharan Africa despite the preventive measures like vaccination that target under five-year-old children and health systems strengthening efforts like prioritizing the supply chain for supplies. Measles immunization coverage for Kasese district and Bugoye HC III in 2018 was 72 and 69%, respectively. This coverage has been very low and always marked red in the Red categorization (below the national target/poor performing) on the national league table indicators. The aim of this study was to assess the scope of the 2018-2019 measles outbreak and the associated risk factors among children aged 0-60 months in Bugoye sub-county, Kasese district, western Uganda.

METHODS

We conducted a retrospective unmatched case-control study among children aged 0-60 months with measles (cases) who had either a clinical presentation or a laboratory confirmation (IgM positivity) presenting at Bugoye Health Centre III (BHC) or in the surrounding communities between December 2018 and October 2019.. Caregivers of the controls (whose children did not have measles) were selected at the time of data collection in July 2020. A modified CDC case investigation form was used in data collection. Quantitative data was collected and analyzed using Microsoft excel and STATA version 13. The children's immunization cards and health registers at BHC were reviewed to ascertain the immunization status of the children before the outbreak.

RESULTS

An extended measles outbreak occurred in Bugoye, Uganda occured between December 2018 and October 2019. All 34 facility-based measles cases were documented to have had maculopapular rash, conjunctivitis, and cough. Also, the majority had fever (97%), coryza (94.1%), lymphadenopathy (76.5%), arthralgias (73.5%) and Koplik Spots (91.2%) as documented in the clinical registers. Similar symptoms were reported among 36 community-based cases. Getting infected even after immunized, low measles vaccination coverage were identified as the principal risk factors for this outbreak.

CONCLUSION

Measles is still a significant problem. This study showed that this outbreak was associated with under-vaccination. Implementing a second routine dose of measles-rubella vaccine would not only increase the number of children with at least one dose but also boost the immunity of those who had the first dose.

Measles outbreak investigation process in low- and middle-income countries: a systematic review of the methods and costs of contact tracing

Aim

The occurrence of measles outbreaks has increased, and previously measles-free countries are experiencing a resurgence, making measles elimination by 2020 unlikely. Therefore, outbreak prevention and rapid response strategies will need to be intensified. This systematic review therefore examines whether contact tracing (CT) as compared to no CT is an effective means of reducing measles spread during outbreaks in low- and middle-income countries (LMICs).

Subject and methods

A systematic review was conducted by searching six databases (CINAHL, Global Health, Medline, Cochrane Library, Web of Science and PubMed). The 17 included articles were appraised using the Critical Appraisal Skills Programme checklists and analysed using a narrative synthesis.

Results

CT is often used alongside mass communication strategies and hospital record checks. Interviewing measles cases to identify contacts, and considering everyone who has shared a space with a case as a contact are common CT methods. Also, CT can be done backwards and/or forwards with the measles case as the focal point of the investigation process. The cost per case of an outbreak response dominated by CT is high especially in terms of labour for the health sector and productivity losses for households. However, overall outbreak expenditure can be low if CT results in fewer and less severe measles cases and a short outbreak duration.

Conclusion

CT data as a standalone and comparative active surveillance approach in LMICs is scarce. If CT is initiated early, it can prevent large outbreaks, thereby reducing the economic burden of measles and drive LMICs towards measles elimination.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-021-01590-2.

Outbreak response operations during the US measles epidemic, 2017-19

BACKGROUND

To understand operational challenges involved with responding to US measles outbreaks in 2017-19 and identify applicable lessons in order to inform preparedness and response operations for future outbreaks, particularly with respect to specific operational barriers and recommendations for outbreak responses among insular communities.

METHODS

From August 2019 to January 2020, we conducted 11 telephone interviews with 18 participants representing state and local health departments and community health centers that responded to US measles outbreaks in 2017-19, with a focus on outbreaks among insular communities. We conducted qualitative, thematic coding to identify and characterize key operational challenges and lessons identified by the interviewees.

RESULTS

We categorized principal insights into 5 topic areas: scale of the response, vaccination operations, exclusion policies, community engagement, and countering anti-vaccine efforts. These topics address resource-intensive aspects of these outbreak responses, including personnel demands; guidance needed to support response operations and reduce transmission, such as excluding exposed or at-risk individuals from public spaces; operational challenges and barriers to vaccination and other response activities; and effectively engaging and educating affected populations, particularly with respect to insular and vulnerable communities.

CONCLUSIONS

Measles outbreak responses are resource intensive, which can quickly overwhelm existing public health capacities. Early and effective coordination with trusted leaders and organizations in affected communities, including to provide vaccination capacity and facilitate community engagement, can promote efficient response operations. The firsthand experiences of public health and healthcare personnel who responded to measles outbreaks, including among insular communities, provide evidence-based operational lessons that can inform future preparedness and response operations for outbreaks of highly transmissible diseases.

Severe acute disseminated encephalomyelitis complicating measles infection

A 36-year-old man presented with an acute progressive encephalopathy, followed by tetraparesis and was diagnosed with acute disseminated encephalomyelitis (ADEM) complicating infection with measles virus. Despite demonstrating a typical rash and other early symptoms of measles infection, there was uncertainty around the initial diagnosis. Cerebrospinal fluid analysis and MRI of the brain and spinal cord were consistent with severe ADEM. He required treatment on intensive care but responded favourably to immunosuppressive therapy.This case highlights the importance of recognising acute measles infection, familiarity with the neurological complications and the potential for good outcome. Healthcare professionals must continue to play an active role in educating the public on the importance of maintaining herd immunity through universal immunisation.

Sero-Prevalence Surveillance to Predict Vaccine-Preventable Disease Outbreaks; A Lesson from the 2014 Measles Epidemic in Northern Vietnam

Background

During the first half of 2014, a severe outbreak of measles occurred in northern Vietnam, causing 15 033 confirmed cases and 146 deaths.

Methods

To evaluate the population-level seroprevalence of protection against measles in the period before the outbreak, we made use of an existing age-stratified serum bank, collected over the year before the outbreak, between November 2012 and December 2013, from 4 sites across the country (Hanoi, Hue, Dak Lak, and Ho Chi Minh City). Data from the UNICEF’s Multiple Indicator Clustered Surveys (MICS), carried out in Vietnam during the first quarter of 2014, were used to assess the vaccine coverage in 6 ecological regions of Vietnam.

Results

Results revealed a large discrepancy between levels of protection, as estimated from the serology and vaccine coverage estimated by UNICEF’s MICS. Variation in seroprevalence across locations and age groups corresponded with reported numbers of measles cases, most of which were among the 0–2-year-old age group and in the northern part of the country.

Conclusions

Our study presents a strong case in favor of a serosurveillance sentinel network that could be used to proactively tune vaccination policies and other public health interventions.

Enhancement of safety and immunogenicity of the Chinese Hu191 measles virus vaccine by alteration of the S-adenosylmethionine (SAM) binding site in the large polymerase protein

The live-attenuated measles virus (MV) vaccine based on the Hu191 strain has played a significant role in controlling measles in China. However, it has considerable adverse effects that may cause public health burden. We hypothesize that the safety and efficacy of MV vaccine can be improved by altering the S-adenosylmethionine (SAM) binding site in the conserved region VI of the large polymerase protein. To test this hypothesis, we established an efficient reverse genetics system for the rMV-Hu191 strain and generated two recombinant MV-Hu191 carrying mutations in the SAM binding site. These two mutants grew to high titer in Vero cells, were genetically stable, and were significantly more attenuated in vitro and in vivo compared to the parental rMV-Hu191 vaccine strain. Importantly, both MV-Hu191 mutants triggered a higher neutralizing antibody than rMV-Hu191 vaccine and provided complete protection against MV challenge. These results demonstrate its potential for an improved MV vaccine candidate.

•

An efficient reverse genetics system for Chinese MV-Hu191 strain was developed.

•

rMV-Hu191 mutants in SAM binding site are attenuated in vitro and in vivo.

•

rMV-Hu191 mutants in SAM binding site enhance the safety and immunogenicity of MV vaccine.

Lung Infections

A review of pulmonary infections of all types with diagnostic and morphological features.

Global Transmission Dynamics of Measles in the Measles Elimination Era

Although there have been many epidemiological reports of the inter-country transmission of measles, systematic analysis of the global transmission dynamics of the measles virus (MV) is limited. In this study, we applied phylogeographic analysis to characterize the global transmission dynamics of the MV using large-scale genetic sequence data (obtained for 7456 sequences) from 115 countries between 1954 and 2015. These analyses reveal the spatial and temporal characteristics of global transmission of the virus, especially in Australia, China, India, Japan, the UK, and the USA in the period since 1990. The transmission is frequently observed, not only within the same region but also among distant and frequently visited areas. Frequencies of export from measles-endemic countries, such as China, India, and Japan are high but decreasing, while the frequencies from countries where measles is no longer endemic, such as Australia, the UK, and the USA, are low but slightly increasing. The world is heading toward measles eradication, but the disease is still transmitted regionally and globally. Our analysis reveals that countries wherein measles is endemic and those having eliminated the disease (apart from occasional outbreaks) both remain a source of global transmission in this measles elimination era. It is therefore crucial to maintain vigilance in efforts to monitor and eradicate measles globally.

Host-Pathogen Interactions in Measles Virus Replication and Anti-Viral Immunity

The measles virus (MeV) is a contagious pathogenic RNA virus of the family Paramyxoviridae, genus Morbillivirus, that can cause serious symptoms and even fetal complications. Here, we summarize current molecular advances in MeV research, and emphasize the connection between host cells and MeV replication. Although measles has reemerged recently, the potential for its eradication is promising with significant progress in our understanding of the molecular mechanisms of its replication and host-pathogen interactions.

A systematic review of human-to-human transmission of measles vaccine virus

Measles is one of the most contagious human diseases. Administration of the live attenuated measles vaccine has substantially reduced childhood mortality and morbidity since its licensure in 1963. The live but attenuated form of the vaccine describes a virus poorly adapted to replicating in human tissue, but with a replication yield sufficient to elicit an immune response for long-term protection. Given the high transmissibility of the wild-type virus and that transmission of other live vaccine viruses has been documented, we conducted a systematic review to establish if there is any evidence of human-to-human transmission of the live attenuated measles vaccine virus. We reviewed 773 articles for genotypic confirmation of a vaccine virus transmitted from a recently vaccinated individual to a susceptible close contact. No evidence of human-to-human transmission of the measles vaccine virus has been reported amongst the thousands of clinical samples genotyped during outbreaks or endemic transmission and individual case studies worldwide.