Latitude and Weather Influence Incidence of Legionnaires' in the US

REESE BARRETT, Dewansh Rastogi, Akua Asa-Awuku, University of Maryland, College Park

     Abstract Number: 567
     Working Group: Aerosol Science of Infectious Diseases: What We Have Learned and Still Need to Know about Transmission, Prevention, and the One Health Concept

Abstract
Legionnaires’ disease, first detected in 1977, is a pneumonia caused by Legionella bacteria, usually L. pneumophila. Person-to-person transmission is not observed, but outbreaks can occur and exposure to clusters of people is common. Usually, infection is caused by the inhalation of aerosols that contain the bacteria. Since the first known outbreak in 1976, incidence of Legionnaires’ disease has been increasing annually. Some environmental conditions that can lead to outbreaks have been studied on regional scales and documented in the literature. In this work, we investigate the correlation of weather conditions to Legionnaires’ disease in the US from extensive meteorological data and public health records (totaling 62,052 data points). Weather data on temperature, precipitation, and relative humidity from each weather station available in the National Climatic Data Center database was compared with all available historical data from the Centers for Disease Control and Prevention on the incidence of Legionnaires’ disease from the years of 1996 to 2019. It was determined that a normally-distributed correlation between the change in average temperature and incidence exists, with less temperature variation present during high levels of incidence. Moreover, a quasi-linear correlation (R2 = 0.7148) between latitude and incidence was discovered, with lower latitude states in the United States consistently presenting higher levels of incidence. Results of this work indicate that warm locations with minimal temperature variability are likely to experience the most Legionnaires’ cases. As global weather patterns continue to change over time, disease incidence will likely change as well, but further analysis is needed to clarify this relationship.