Cellphone activity could be used to monitor and predict spread of the new coronavirus, researchers say.

They analyzed cellphone use in more than 2,700 U.S. counties between early January and early May to identify where the phones were used, including workplaces, homes, retail and grocery stores, parks and transit stations.

Between 22,000 and 84,000 points of publicly available, anonymous cellphone location data were analyzed for each day in the study period.

Counties with greater declines in workplace cellphone activity during stay-at-home orders had lower rates of COVID-19, according to findings published Aug. 31 in the journal JAMA Internal Medicine.

Researchers said their findings suggest that this type of cellphone data could be used to better estimate COVID-19 growth rates and guide decisions about shutdowns and reopenings.

“It is our hope that counties might be able to incorporate these publicly available cellphone data to help guide policies regarding reopening throughout different stages of the pandemic,” said senior study author Dr. Joshua Baker, an assistant professor of medicine and epidemiology at the University of Pennsylvania School of Medicine.

“Further, this analysis supports the incorporation of anonymized cellphone location data into modeling strategies to predict at-risk counties across the U.S. before outbreaks become too great,” he added in a university news release.

Baker said it also may be possible to use cellphone data to forecast hotspots and take action. But, he added, it will be important to confirm that the data is useful at other stages of the pandemic beyond initial containment.

This type of data could also prove important in the future, he said.

“They do have the potential to help us better understand behavioral patterns which could help future investigators predict the course of future epidemics or perhaps monitor the impact of different public health measures on peoples’ behaviors,” Baker said.

More information

The U.S. Centers for Disease Control and Prevention has more on COVID-19.