The Association Between Meteorological Conditions And Respiratory Syncytial Virus Activity In The Northeast United States, 2007-2014

Abstract

Introduction: Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory tract infections among young children globally and in the United States (US). RSV activity often displays a seasonal peak in temperate climates, but also exhibits regional and local trends. This suggests that RSV incidence may be influenced by regional factors, such as meteorological conditions. A better understanding of how weather patterns affect RSV activity could help predict the timing and burden of the RSV season. Methods: In the US, the National Respiratory and Enteric Virus Surveillance System monitors RSV activity by collecting data on the number of specimens tested for RSV and the number of tests positive for RSV. Using this surveillance data, we calculated the weekly percent positive tests for RSV, and then linked the weekly percentages to weather measurements made at airport weather monitoring stations located within US Department of Health and Human Services Region 1 (i.e. Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont). Generalized additive models with autoregressive terms examined exposure in the prior 3 weeks using distributed lags, and adjusted for season, time trend, and influenza activity (i.e. the weekly percentage positive tests for influenza). Results: From July 2007 through December 2014, each 1°C decrease in temperature in the previous week (lag 1) increased RSV activity by 0.09% (95% confidence interval (CI) 0.01-0.16%), and by 0.11% (95% CI 0.03-0.19%) at lag 2. Collectively, a 1°C decrease in each of the 2 previous weeks increased RSV activity by 0.19% (95% CI 0.09-0.30%). The temperature effect was not significant beyond lag 2 weeks. Relative humidity and specific humidity were not associated with RSV activity. Discussion: Meteorological conditions influence RSV activity in the northeast US. Lower temperatures, particularly in the prior two weeks, are associated with increased RSV activity.