Comparative Analysis of Seasonality of Childhood Infections in Seven United States Cities in the Pre-Vaccination era
Monday, November 2, 2015
: 3:30 p.m. - 3:50 p.m.
The recent resurgence of vaccine preventable childhood infections in North America highlights how we may still benefit from a greater understanding of their epidemic dynamics. Seasonality is observed for several of these infections but underlying patterns and drivers remain incompletely understood. We used weekly disease incidence data from Project TYCHO™ for New York City, Chicago, Baltimore, Atlanta, New Orleans, Denver, and Los Angeles from 1924 to 1947 and a time-series susceptible-infected-recovered model to assess seasonal patterns and drivers (temperature, school term, and absolute humidity) of measles, scarlet fever, pertussis, and diphtheria. Measles and scarlet fever exhibited peaks in transmission during early winter months, diphtheria showed a peak in fall, while pertussis peaked in early spring. We found strong positive Pearson correlation coefficients of seasonal basic reproductive numbers (R0) between measles and scarlet fever within six cities (range: 0.78-0.90). We also observed strong positive correlations of the seasonal R0 of measles between cities (0.77-0.97) and when comparing R0 estimates between cities for scarlet fever (0.49-0.96). We observed weaker correlation of R0 estimates for pertussis (0.16-0.79) and diphtheria (0.31-0.92). Correlation of estimated seasonal forcing with climate data suggested that absolute humidity accounted for much of the annual variability seen in measles. The examined drivers failed to explain variability observed in scarlet fever, diphtheria, or pertussis. Understanding the seasonality, amplitude, and driving mechanisms of epidemics of childhood diseases are important for informing preparedness and vaccine implementation.
Protection of the public in relation to communicable diseases including prevention or control
Public health or related public policy
Public health or related research
Identify seasonal patterns of childhood infections prior to vaccine implementation
Presenting author's disclosure statement:
Qualified on the content I am responsible for because: I have worked in the field of infectious disease epidemiology for several years focusing on the epidemiology and surveillance of zoonotic, vector-borne, and respiratory diseases.
Any relevant financial relationships? No
I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines,
and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed
in my presentation.