The weekly time series of ED visits and reported cases were overlaid on Google search engine data, as a measure of public awareness of the outbreak. Data were visualized with the use of Google Trends for U.S. searches related to e-cigarette or vaping products . Google Trends scores range from 0 to 100, with a score of 100 indicating peak interest and a score of 50 indicating that the search term is half as popular as at its peak.Longer-term trends were assessed as the ED visits returned by each query per 1 million reported ED visits . To identify weeks when the trend in ED visit rates changed for each query, we identified knots with the use of the segmented package in R software, version 3.6. Piecewise linear splines were fit between knots to estimate the change in visit rates during each period of interest.