LOS ANGELES (KABC) -- Ahead of the Thanksgiving holiday, health officials warned families to stay home and stay safe, but millions of people chose to travel long distances anyway, and in the weeks that followed, many counties have reported an uptick in coronavirus cases.
Analysis by Eyewitness News shows many of the counties that saw the biggest jump in long-distance travel during Thanksgiving week also saw an uptick in positive coronavirus cases in the week following the holiday, Nov. 29 through Dec. 6.
Using data tracking new coronavirus cases from Johns Hopkins University and travel data from the Bureau of Transportation Statistics, Eyewitness News found Los Angeles County experienced the highest uptick in average new daily infections the week after Thanksgiving nationwide. L.A. County also saw the second highest number of people in the country traveling 500 miles or more over the holiday week.
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Riverside and San Bernardino Counties weren't far behind L.A. County. They had the third and fourth highest increases in average new daily cases, according to the data, and both counties were also among the top 50 for long distance travel over the holiday week.
Even after adjusting for population differences among counties across the country, Los Angeles, Riverside and San Bernardino Counties remained in the top 11% nationwide for new cases the week after Thanksgiving.
"These Thanksgiving surges of cases on top of already rising cases is creating extraordinary stress on our healthcare system," said L.A. County Public Health Director Dr. Barbara Ferrer. "Should this be followed by another surge related to the winter holiday, the numbers of hospitalizations and patients in the ICU could be catastrophic."
Nationally, 18 of the top 20 counties reporting the most "long-distance" travelers during Thanksgiving week also saw increases in the average number of daily new COVID-19 cases the week following the holiday.
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The counties experiencing an uptick in cases included travel-hub cities such as L.A., Dallas, Phoenix, Miami, Houston and New York City.
Additionally, several airports in counties experiencing an uptick in travel reported at least one new coronavirus case among TSA workers during the week following Thanksgiving.
Other factors beyond travel that weren't measured by this data could have also impacted the number of new infections in the week following Thanksgiving, including whether travelers properly wore protective gear, where travelers visited, how many people they saw over the holiday and testing differences over the period analyzed.
Additionally, this analysis may not capture the full impact of Thanksgiving travel on the pandemic, as many health officials believe the U.S. has not yet seen the peak of new COVID-19 cases related to Thanksgiving travel.
Health officials are yet again warning families to limit travel for the remainder of the holiday season as the Christmas and New Year's Eve holidays approach.