COVID-19 may surge in Manatee, Southwest Florida, thermometer data indicates

Manatee County and Southwest Florida could be on the verge of another rise in cases of the novel coronavirus, warns a company that tracks fevers to spot early signs of spreading disease.

Kinsa Health relies on more than one million internet-connected thermometers across the country to try to detect outbreaks before people can get tested or go to the doctor. Since the COVID-19 pandemic began, the company’s data has shown spikes in certain regions two or three weeks before a similar jump in confirmed cases.

More residents in Hillsborough County have reported fevers than expected for this time of year, according to the company. That spells the potential for a resurgence of the virus, or an abnormal flu outbreak, soon.

“We are assuming that it’s COVID,” said Nita Nehru, a spokeswoman for Kinsa Health. She said they adjust for the normal expected levels of illness based on the part of the country and the time of year.

While other counties in Southwest Florida, including Manatee, show similar data, researchers have greater confidence in the data in Hillsborough because of a higher number of thermometer users there.

Kinsa uses its thermometer data and historical patterns to guess a current transmission rate in each county – a measure of how fast diseases spread between people. A rate of exactly one means each contagious person infects one more; any higher, and outbreaks will grow.

Hillsborough’s rate has been abnormally high for about two weeks, Nehru said. She called the gap between what’s happening and what normally happens this time of year “wildly divergent.” The rate had been below one from early July until late August.

“We are worried that COVID cases may increase in the coming weeks, and so we urge everyone to take appropriate precautions,” she said.

Several counties, especially in Southwest Florida, showed similarly high estimated transmission rates. A map shows the worst region of the state stretching from Manatee to Lee.

The worst counties are showing rates around 1.03. The number sounds small. But exponential growth means tiny changes can make big differences.

If a county’s rate is exactly 1, then 10 infections today means 10 new infections tomorrow. At the end of a month, 300 people will have been infected.

Bump it up to 1.03, just three percent higher, and the number of new infections increases every single day. That adds up to about 475 total infections over the course of a month – 60 percent higher.

Of course, patterns can change if behavior does. The more residents wear masks, and the less they interact with other people – especially in crowded buildings – the better for preventing spread.

Kinsa can’t tell whether their data shows the coronavirus spreading or a similar flu-like disease, but they already adjust for the regular seasonal flu in their data, Nehru said. For example, the same data identified an abnormal flu outbreak in 2019 in Houston.

“We don’t know for a fact,” Nehru said, “but the transmission we’re seeing is notably higher than (normal for) this time of year from only flu.”

An article in the scientific journal Engineering notes a recent study indicated the smart thermometer data led to better flu outbreak predictions. Isolating coronavirus outbreaks is harder, however, because most people don’t have the thermometers, not everyone with COVID-19 gets a fever, and fevers can be signs of many illnesses.

Still, there are examples of the Kinsa data preceding notable coronavirus case spikes last month. After high transmission rate estimates in North and South Dakota in August, confirmed cases jumped in both states. A similar pattern emerged around Lubbock, Texas.

As of Thursday, Hillsborough is reporting about 173 new cases of the coronavirus every day (using a weekly average). That number has been generally flat, with a slight increase for a few days, a setback considering there had previously been constant improvement since July.

New case numbers are also flat or slightly rising in several counties with high estimated transmission rates: Manatee, Sarasota, Lee, Hardee, Highlands and Glades.

Southwest Florida counties also show a slowdown in the improvement in current coronavirus hospitalizations. None have shown the number of people diagnosed in hospitals increase for a long period, but many have seen the improvement slow since the beginning of September. Pinellas was stagnant for more than two weeks before making more improvement in the past week.

At the statewide level, Nehru said, the overall rate has ticked up, but has not yet been high for long enough to be a clear trend. That’s because the most populous counties, in South Florida, do not show rates as high, although they are rising in recent days.

This story was originally published September 18, 2020 at 10:06 AM.