Air Passenger Travel and International Surveillance Data Predict Spatiotemporal Variation in Measles Importations to the United States

Measles incidence in the United States has grown dramatically, as vaccination rates are declining and transmission internationally is on the rise. Because imported cases are necessary drivers of outbreaks in non-endemic settings, predicting measles outbreaks in the US depends on predicting imported...

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Main Authors: Marya L. Poterek, Moritz U. G. Kraemer, Alexander Watts, Kamran Khan, T. Alex Perkins
Format: Article
Language:English
Published: MDPI AG 2021-02-01
Series:Pathogens
Subjects:
Online Access:https://www.mdpi.com/2076-0817/10/2/155
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author Marya L. Poterek
Moritz U. G. Kraemer
Alexander Watts
Kamran Khan
T. Alex Perkins
author_facet Marya L. Poterek
Moritz U. G. Kraemer
Alexander Watts
Kamran Khan
T. Alex Perkins
author_sort Marya L. Poterek
collection DOAJ
description Measles incidence in the United States has grown dramatically, as vaccination rates are declining and transmission internationally is on the rise. Because imported cases are necessary drivers of outbreaks in non-endemic settings, predicting measles outbreaks in the US depends on predicting imported cases. To assess the predictability of imported measles cases, we performed a regression of imported measles cases in the US against an inflow variable that combines air travel data with international measles surveillance data. To understand the contribution of each data type to these predictions, we repeated the regression analysis with alternative versions of the inflow variable that replaced each data type with averaged values and with versions of the inflow variable that used modeled inputs. We assessed the performance of these regression models using correlation, coverage probability, and area under the curve statistics, including with resampling and cross-validation. Our regression model had good predictive ability with respect to the presence or absence of imported cases in a given state in a given year (area under the curve of the receiver operating characteristic curve (AUC) = 0.78) and the magnitude of imported cases (Pearson correlation = 0.84). By comparing alternative versions of the inflow variable averaging over different inputs, we found that both air travel data and international surveillance data contribute to the model’s ability to predict numbers of imported cases and individually contribute to its ability to predict the presence or absence of imported cases. Predicted sources of imported measles cases varied considerably across years and US states, depending on which countries had high measles activity in a given year. Our results emphasize the importance of the relationship between global connectedness and the spread of measles. This study provides a framework for predicting and understanding imported case dynamics that could inform future studies and outbreak prevention efforts.
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spelling doaj.art-1731550352c64908bfa1168b6e9189802023-12-03T12:10:58ZengMDPI AGPathogens2076-08172021-02-0110215510.3390/pathogens10020155Air Passenger Travel and International Surveillance Data Predict Spatiotemporal Variation in Measles Importations to the United StatesMarya L. Poterek0Moritz U. G. Kraemer1Alexander Watts2Kamran Khan3T. Alex Perkins4Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556, USADepartment of Zoology, University of Oxford, Oxford OX1 3SY, UKLi Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, ON M5B 1T8, CanadaLi Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, ON M5B 1T8, CanadaDepartment of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556, USAMeasles incidence in the United States has grown dramatically, as vaccination rates are declining and transmission internationally is on the rise. Because imported cases are necessary drivers of outbreaks in non-endemic settings, predicting measles outbreaks in the US depends on predicting imported cases. To assess the predictability of imported measles cases, we performed a regression of imported measles cases in the US against an inflow variable that combines air travel data with international measles surveillance data. To understand the contribution of each data type to these predictions, we repeated the regression analysis with alternative versions of the inflow variable that replaced each data type with averaged values and with versions of the inflow variable that used modeled inputs. We assessed the performance of these regression models using correlation, coverage probability, and area under the curve statistics, including with resampling and cross-validation. Our regression model had good predictive ability with respect to the presence or absence of imported cases in a given state in a given year (area under the curve of the receiver operating characteristic curve (AUC) = 0.78) and the magnitude of imported cases (Pearson correlation = 0.84). By comparing alternative versions of the inflow variable averaging over different inputs, we found that both air travel data and international surveillance data contribute to the model’s ability to predict numbers of imported cases and individually contribute to its ability to predict the presence or absence of imported cases. Predicted sources of imported measles cases varied considerably across years and US states, depending on which countries had high measles activity in a given year. Our results emphasize the importance of the relationship between global connectedness and the spread of measles. This study provides a framework for predicting and understanding imported case dynamics that could inform future studies and outbreak prevention efforts.https://www.mdpi.com/2076-0817/10/2/155air travelimportationglobal healthmeasles
spellingShingle Marya L. Poterek
Moritz U. G. Kraemer
Alexander Watts
Kamran Khan
T. Alex Perkins
Air Passenger Travel and International Surveillance Data Predict Spatiotemporal Variation in Measles Importations to the United States
Pathogens
air travel
importation
global health
measles
title Air Passenger Travel and International Surveillance Data Predict Spatiotemporal Variation in Measles Importations to the United States
title_full Air Passenger Travel and International Surveillance Data Predict Spatiotemporal Variation in Measles Importations to the United States
title_fullStr Air Passenger Travel and International Surveillance Data Predict Spatiotemporal Variation in Measles Importations to the United States
title_full_unstemmed Air Passenger Travel and International Surveillance Data Predict Spatiotemporal Variation in Measles Importations to the United States
title_short Air Passenger Travel and International Surveillance Data Predict Spatiotemporal Variation in Measles Importations to the United States
title_sort air passenger travel and international surveillance data predict spatiotemporal variation in measles importations to the united states
topic air travel
importation
global health
measles
url https://www.mdpi.com/2076-0817/10/2/155
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