DeSantis Rekindles His Love for Florida’s Virus Positivity Rate

(Bloomberg) -- In recent weeks, Ron DeSantis has been negative on the state’s positivity rate, but on Thursday he was pretty positive the positivity rate is actually a positive.

Florida’s percentage of Covid-19 tests that come back positive fell to the lowest since mid-June, leading the Republican governor to tout the metric on Twitter -- an about-face for the erstwhile positivity-rate skeptic.

His shift shows how elected officials have broad latitude to pick their own lessons from the broad palette of Covid-19 data points, which don’t always agree.

In June, when case numbers were rising, but positivity rates were low, DeSantis insisted positivity was the favored way to judge Covid-19’s prevalence. Positivity rates eventually caught up with case numbers.

Then, this month, when stubbornly high positivity rates undermined his push to get schools to reopen, DeSantis started to downplay the accuracy of the metric, saying some smaller, private labs don’t consistently report the negatives, which would make rates appear higher.

“I’d be very cautious of tying a child’s future to the efficacy of some private lab dumping the results into a system,” he said Aug. 4.

Positivity can be measured several ways. But the rate of people testing positive for the first time slipped to 6.8% for Wednesday, from 7.1% on Tuesday. It’s the lowest since June 14, when a Covid-19 resurgence started taking hold in the Sun Belt.

A Fox 35 Orlando report last month showed how some small labs had impossibly high positivity rates, and the Florida Department of Health subsequently said some had failed to report negatives. At the time, it said it was contacting them to ensure proper reporting protocols.

But small labs have a limited ability to sway results, even with egregious errors. Well over 1,000 labs contribute results to the state’s data, but the top six account for 55% of tests. The cumulative positivity rate among those major labs was broadly in line with the statewide figure.

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