Dataset Information

Measles outbreak risk in Pakistan: exploring the potential of combining vaccination coverage and incidence data with novel data-streams to strengthen control.

ABSTRACT: Although measles incidence has reached historic lows in many parts of the world, the disease still causes substantial morbidity globally. Even where control programs have succeeded in driving measles locally extinct, unless vaccination coverage is maintained at extremely high levels, susceptible numbers may increase sufficiently to spark large outbreaks. Human mobility will drive potentially infectious contacts and interact with the landscape of susceptibility to determine the pattern of measles outbreaks. These interactions have proved difficult to characterise empirically. We explore the degree to which new sources of data combined with existing public health data can be used to evaluate the landscape of immunity and the role of spatial movement for measles introductions by retrospectively evaluating our ability to predict measles outbreaks in vaccinated populations. Using inferred spatial patterns of accumulation of susceptible individuals and travel data, we predicted the timing of epidemics in each district of Pakistan during a large measles outbreak in 2012-2013 with over 30 000 reported cases. We combined these data with mobility data extracted from over 40 million mobile phone subscribers during the same time frame in the country to quantify the role of connectivity in the spread of measles. We investigate how different approaches could contribute to targeting vaccination efforts to reach districts before outbreaks started. While some prediction was possible, accuracy was low and we discuss key uncertainties linked to existing data streams that impede such inference and detail what data might be necessary to robustly infer timing of epidemics.

SUBMITTER: Wesolowski A

PROVIDER: S-EPMC6090714 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature

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Measles outbreak risk in Pakistan: exploring the potential of combining vaccination coverage and incidence data with novel data-streams to strengthen control.

Wesolowski Amy A Winter Amy A Tatem Andrew J AJ Qureshi Taimur T Engø-Monsen Kenth K Buckee Caroline O CO Cummings Derek A T DAT Metcalf C Jessica E CJE

Epidemiology and infection 20180604 12

Although measles incidence has reached historic lows in many parts of the world, the disease still causes substantial morbidity globally. Even where control programs have succeeded in driving measles locally extinct, unless vaccination coverage is maintained at extremely high levels, susceptible numbers may increase sufficiently to spark large outbreaks. Human mobility will drive potentially infectious contacts and interact with the landscape of susceptibility to determine the pattern of measles ...[more]

PMID: 29860954

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Project description:BackgroundOf the eight large (>50 cases) US postelimination outbreaks, the first and last occurred in Ohio. Ohio's vaccination registry is incomplete. Community-level immunity gaps threaten more than two decades of measles elimination in the US. We developed a statistical model, VaxEstim, to rapidly estimate the early-phase vaccination coverage and immunity gap in the exposed population during the 2022 Central Ohio outbreak.MethodsWe used reconstructed daily incidence (from publicly available data) and assumptions about the distribution of the serial interval, or the time between symptom onset in successive measles cases, to estimate the effective reproduction number (i.e., the average number of secondary infections caused by an infected individual in a partially immune population). We estimated early-phase measles vaccination coverage by comparing the effective reproduction number to the basic reproduction number (i.e., the average number of secondary infections caused by an infected individual in a fully susceptible population) while accounting for vaccine effectiveness. Finally, we estimated the early-phase immunity gap as the difference between the estimated critical vaccination threshold and vaccination coverage.FindingsVaxEstim estimated the early-phase vaccination coverage as 53% (95% credible interval, 21%-77%), the critical vaccination threshold as 93%, and the immunity gap as 42% (95% credible interval, 18%-74%).InterpretationThis study estimates a significant immunity gap in the exposed population during the early phase of the 2022 Central Ohio measles outbreak, suggesting a robust public health response is needed to identify the susceptible community and develop community-specific strategies to close the immunity gap.FundingThis work was supported in part by the National Institute of General Medical Sciences, National Institutes of Health; the UK Medical Research Council (MRC); the Foreign, Commonwealth and Development Office; the National Institute for Health Research (NIHR) Health Protection Research Unit in Modelling Methodology; Imperial College London, and the London School of Hygiene & Tropical Medicine, Community Jameel; the EDCTP2 programme, supported by the EU; and the Sergei Brin Foundation.

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Project description:BackgroundA measles outbreak occurred in a western county of China in 2013, the year after China's historic nadir of measles. We conducted a field investigation to identify gaps in measles vaccination coverage and immunization program weaknesses, and to provide recommendations for measles outbreak response and immunization program improvement.MethodsWe analyzed surveillance data from 2008 to 2013 to describe the measles epidemiology of the county. Measles-containing vaccine coverage was estimated using two methods: previously-reported administrative coverage and an estimation of coverage by clinic-kept vaccination records (n = 542). We conducted a rapid field coverage assessment in a migrant population village to evaluate coverage after emergency vaccination. We conducted a review of hospital records of measles cases to address the role hospital transmission played during the early stage of this outbreak.ResultsThere were 153 cases in the outbreak, primarily among children too young to vaccinate, unvaccinated children less than 3 years old, and adults. Measles-containing vaccine coverage by the field assessment showed that 20% of children aged 8-17 months had zero doses, and 9% of ≥2 years old children had fewer than two doses. The vaccination statuses of all adult cases were either zero doses or unknown. At least 61% of cases had been hospitalized. The proportion of cases who had been hospital-exposed 7 to 21 days prior to rash onset decreased from 52% to 22% after hospitals strengthen their isolation measures.ConclusionsThis outbreak was a result of measles vaccination coverage gaps among young children and adults, and insufficient hospital isolation of cases. The lower coverage seen in the field estimation compared with reported coverage showed that reported coverage could have been overestimated. Hospitals were sites of transmission in the early stage of the outbreak. A strict hospital isolation policy could decrease spread of measles. Emergency vaccination was associated with stopping measles transmission in low coverage areas.

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Project description:Background:There is a global resurgence of measles, consequent upon worldwide stagnating measles vaccination coverage. The study aim was to document trends and characteristics of reported cases of measles, measles-related deaths, and measles vaccination coverage (MCV1-first dose of measles-containing vaccine and MCV2-second dose of measles-containing vaccine) at national and sub-national level in Myanmar over a five year period between 2014 and 2018. Methods:This was a descriptive study using routine data collected and submitted to the Expanded Programme on Immunization. Results:Between 2014 and 2018, there were 2673 measles cases of which 2272 (85%) occurred in 2017 and 2018. Five adjacent regions in lower Myanmar were the most affected: in 2017 and 2018, these regions reported 1647 (73%) of the 2272 measles cases in the country. Overall, 73% of measles cases were laboratory confirmed, 21% were epidemiologically linked, and 6% were clinically compatible (clinical diagnosis only), with more laboratory confirmed cases in recent years. Annual measles-related deaths were either zero or one except in 2016 when there were 21 deaths, all occurring in one remote village. In the recent years, the most commonly affected age groups were 0-8 months, 9 months to 4 years, and ??15 years. Among 1907 measles cases with known vaccination status, only 22% had been vaccinated and 70% of those had only received one dose of vaccine. Annual MCV1 coverage nationally varied from 83 to 93% while annual MCV2 coverage nationally varied from 78 to 87%, with no clear trends over the years. Between 2014 and 2018, a high proportion of the 330 townships had MCV coverage <?95%. Over 80% of measles cases were reported from townships that had MCV coverage <?95%. Conclusion:There have been a large number of measles cases in recent years associated with sub-optimal measles vaccine coverage. Myanmar has already conducted supplemental immunization activities in October and November, 2019. Myanmar also needs to improve routine immunization services and targeted responses to measles outbreaks.

Dataset Information

Measles outbreak risk in Pakistan: exploring the potential of combining vaccination coverage and incidence data with novel data-streams to strengthen control.

Publications

Measles outbreak risk in Pakistan: exploring the potential of combining vaccination coverage and incidence data with novel data-streams to strengthen control.

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