TY - JOUR
T1 - Spatio-temporal comparison of pertussis outbreaks in Olmsted County, Minnesota, 2004-2005 and 2012
T2 - A population-based study
AU - Wi, Chung Il
AU - Wheeler, Philip H.
AU - Kaur, Harsheen
AU - Ryu, Euijung
AU - Kim, Dohyeong
AU - Juhn, Young
N1 - Funding Information:
Funding YJ is the PI of 'The 2015 Innovative Methods for Asthma Award' supported by Genentech, the PI of Real World Evidence Pediatric Asthma Study supported by Roche/Genentech, and an advisory board member for Real World Evidence Project for Asthma supported by Genentech. This publication was made possible by CTSA Grant Number UL1 TR000135 from the National Center for Advancing Translational Sciences (NCATS), a component of the National Institutes of Health (NIH) and the resources of the Rochester Epidemiology Project (R01-AG34676) from the National Institute on Aging.
Funding Information:
1Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA 2Department of Pediatrics, Univeristy of New Mexico, Albuquerque, New Mexico, USA 3Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota, USA 4Geospatial Health Research Group, School of Economic, Political and Policy Sciences, University of Texas at Dallas, Richardson, Texas, USA 5Department of Community Pediatrics and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA Acknowledgements This publication was made possible by CTSA Grant Number UL1 TR000135 from the National Center for Advancing Translational Sciences (NCATS), a component of the National Institutes of Health (NIH) and the resources of the Rochester Epidemiology Project (R01-AG34676) from the National Institute on Aging. Its contents are solely the responsibility of the authors and do not necessarily represent the official view of NIH. We would like to thank to Dr. Robin Patel for her data sharing and critical review and comments, Dr. Thomas G. Boyce, Dr. Raj Mody, Ms. Cynthia Kenyon and Mr. Victor Cruz for their critical review and comments, and Mrs. Kelly Okeson for her administrative assistance.
Publisher Copyright:
© Author(s) (or their employer(s)) 2018.
PY - 2019/5/17
Y1 - 2019/5/17
N2 - Objective Two pertussis outbreaks occurred in Olmsted County, Minnesota, during 2004-2005 and 2012 (5-10 times higher than other years), with significantly higher incidence than for the State. We aimed to assess whether there were similar spatio-temporal patterns between the two outbreaks. Setting Olmsted County, Minnesota, USA Participants We conducted a population-based retrospective cohort study of all Olmsted County residents during the 2004-2005 and 2012 outbreaks, including laboratory-positive pertussis cases. Primary outcome measure For each outbreak, we estimated (1) age-specific incidence rate using laboratory-positive pertussis cases (numerator) and the Rochester Epidemiology Project Census (denominator), a medical record-linkage system for virtually all Olmsted County residents, and (2) pertussis case density using kernel density estimation to identify areas with high case density. To account for population size, we calculated relative difference of observed density and expected density based on age-specific incidence. Results We identified 157 and 195 geocoded cases in 2004-2005 and 2012, respectively. Incidence was the highest among adolescents (ages 11 to <14 years) for both outbreaks (9.6 and 7.9 per 1000). The 2004-2005 pertussis outbreak had higher incidence in winter (52% of cases) versus summer in 2012 (53%). We identified a consistent area with higher incidence at the beginning (ie, first quartile) of two outbreaks, but it was inconsistent for later quartiles. The relative difference maps for the two outbreaks suggest a greater role of neighbourhood population size in 2012 compared with 2004-2005. Conclusions Comparing spatio-temporal patterns between two pertussis outbreaks identified a consistent geographical area with higher incidence of pertussis at the beginning of outbreaks in this community. This finding can be tested in future outbreaks, and, if confirmed, can be used for identifying epidemiological risk factors clustered in such areas for geographically targeted intervention.
AB - Objective Two pertussis outbreaks occurred in Olmsted County, Minnesota, during 2004-2005 and 2012 (5-10 times higher than other years), with significantly higher incidence than for the State. We aimed to assess whether there were similar spatio-temporal patterns between the two outbreaks. Setting Olmsted County, Minnesota, USA Participants We conducted a population-based retrospective cohort study of all Olmsted County residents during the 2004-2005 and 2012 outbreaks, including laboratory-positive pertussis cases. Primary outcome measure For each outbreak, we estimated (1) age-specific incidence rate using laboratory-positive pertussis cases (numerator) and the Rochester Epidemiology Project Census (denominator), a medical record-linkage system for virtually all Olmsted County residents, and (2) pertussis case density using kernel density estimation to identify areas with high case density. To account for population size, we calculated relative difference of observed density and expected density based on age-specific incidence. Results We identified 157 and 195 geocoded cases in 2004-2005 and 2012, respectively. Incidence was the highest among adolescents (ages 11 to <14 years) for both outbreaks (9.6 and 7.9 per 1000). The 2004-2005 pertussis outbreak had higher incidence in winter (52% of cases) versus summer in 2012 (53%). We identified a consistent area with higher incidence at the beginning (ie, first quartile) of two outbreaks, but it was inconsistent for later quartiles. The relative difference maps for the two outbreaks suggest a greater role of neighbourhood population size in 2012 compared with 2004-2005. Conclusions Comparing spatio-temporal patterns between two pertussis outbreaks identified a consistent geographical area with higher incidence of pertussis at the beginning of outbreaks in this community. This finding can be tested in future outbreaks, and, if confirmed, can be used for identifying epidemiological risk factors clustered in such areas for geographically targeted intervention.
KW - epidemiology
KW - geographical mapping
KW - public health
UR - http://www.scopus.com/inward/record.url?scp=85065993476&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85065993476&partnerID=8YFLogxK
U2 - 10.1136/bmjopen-2018-025521
DO - 10.1136/bmjopen-2018-025521
M3 - Article
C2 - 31110089
AN - SCOPUS:85065993476
SN - 2044-6055
VL - 9
JO - BMJ Open
JF - BMJ Open
IS - 5
M1 - e025521
ER -