Donald G. McNeil Jr. March
31, 2020, 1:51 PM CDT
New data
shows evidence that U.S. restrictions are slowing coronavirus infections
In Manhattan, reports of fevers rose during
early March, when social distancing was not enforced. But a change began on
March 16 and 17 when schools,
Harsh
measures, including stay-at-home orders and restaurant closures, are
contributing to rapid drops in the numbers of fevers — a signal symptom of most
coronavirus infections — recorded in states across the country, according to
intriguing new data produced by a medical technology firm.
At
least 248 million Americans in at least 29 states have been told to stay at
home. It had seemed nearly impossible for public health officials to know how
effective this measure and others have been in slowing the coronavirus.
But the
new data offer evidence, in real time, that tight social-distancing
restrictions may be working, potentially reducing hospital overcrowding and
lowering death rates, experts said.
The
company, Kinsa Health, which produces internet-connected thermometers, first
created a national map of fever levels on March 22 and was able to spot the
trend within a day. Since then, data from the health departments of New York
state and Washington state have buttressed the finding, making it clear that
social distancing is saving lives.
The
trend has become so obvious that on Sunday, President Donald Trump extended
until the end of April his recommendation that Americans stay in lockdown.
Trump had hoped to lift restrictions by Easter and send Americans back to work.
Gov.
Andrew Cuomo during a coronavirus news conference the Javits Center in New
York, March 23, 2020. (Stephanie Keith/The New York Times)
“That
would have been the worst possible Easter surprise,” said Dr. Peter J. Hotez,
dean of the National School of Tropical Medicine at Baylor College of Medicine
in Houston, who added that he thought the Kinsa predictions were based on “very
robust technology.”
Kinsa’s
thermometers upload the user’s temperature readings to a centralized database;
the data enable the company to track fevers across the United States.
Owners
of Kinsa’s thermometers can type other symptoms into a cellphone app after
taking their temperature. The app offers basic advice on whether they should
seek medical attention.
Kinsa
has more than 1 million thermometers in circulation and has been getting up to
162,000 daily temperature readings since COVID-19 began spreading in the
country.
The
company normally uses that data to track the spread of influenza. Since 2018,
when it had more than 500,000 thermometers distributed, its predictions have
routinely been two to three weeks ahead of those of the Centers for Disease
Control and Prevention, which gathers flu data on patient symptoms from
doctors’ offices and hospitals.
To
identify clusters of coronavirus infections, Kinsa recently adapted its
software to detect spikes of “atypical fever” that do not correlate with
historical flu patterns and are likely attributable to the coronavirus.
As of
noon Wednesday, the company’s live map showed fevers holding steady or dropping
almost universally across the country, with two prominent exceptions.
One was
in a broad swath of New Mexico, where the governor had issued stay-at-home
orders only the day before, and in adjacent counties in southern Colorado.
The
second was in a ring of Louisiana parishes surrounding New Orleans, but 100 to
150 miles away from it. That presumably was caused by the outward local spread
of the explosion of infections in New Orleans, which officials believe was set
off by crowding during Mardi Gras.
By
Friday morning, fevers in every county in the country were on a downward trend,
depicted in four shades of blue on the map.
Fevers
were dropping especially rapidly in the West, from Utah to California and from
Washington down to Arizona; in many Western counties, the numbers of people
reporting high fevers fell by almost 20%. The numbers were also declining
rapidly in Maine.
The
parts of New Mexico and Colorado that had been slightly “warm” on Wednesday
were in light blue, indicating that they were cooling. So were the Louisiana
counties.
As of
Monday morning, more than three-quarters of the country was deep blue. A
separate display of the collective national fever trend, which had spiked
upward to a peak on March 17, had fallen so far that it was actually below the
band showing historical flu fever trends — which meant that the lockdown has
cut not only COVID-19 transmission but flu transmission, too.
“I’m
very impressed by this,” said Dr. William Schaffner, a preventive medicine
expert at Vanderbilt University. “It looks like a way to prove that social
distancing works.”
“But it
does shows that it takes the most restrictive measures to make a real
difference,” he added.
For
some hard-hit cities, Kinsa also sent The New York Times fever data plotted on
a timeline of restrictions enacted by mayors or governors.
Those
graphs, Schaffner noted, showed that simply declaring a state of emergency or
limiting the size of public gatherings did not affect the number of people
reporting fevers.
But
closing restaurants and bars and asking people to stay in their homes produced
dramatic results in all three cities.
For
example, in Manhattan, reports of fevers steadily rose during early March,
despite a declaration of emergency on March 7 and an order on March 12 that
public gatherings be restricted to less than 500 people.
The
turning point began on March 16, the day schools were closed. Bars and
restaurants were closed the next day, and a stay-at-home order took effect on
March 20. By March 23, new fevers in Manhattan were below their March 1 levels.
Last
Friday, New York state’s own data showed the same trend that Kinsa’s fever
readings had spotted five days earlier.
The
state tracks hospitalization rates, not fevers. So many patients were being
admitted to New York City hospitals, Gov. Andrew M. Cuomo said, that until
March 20, hospitalization rates were doubling roughly every two days.
By
Tuesday, the hospitalization rate took four days to double. This is roughly
what the fever readings predicted, said Nita Nehru, a company spokeswoman.
Hospitalizations
occur several days after symptoms like fever appear. “The cases being counted
now had fevers five to 10 days ago,” she said.
The
slowing of new hospital admissions “suggests that our density-control measures
may be working,” Cuomo said Wednesday.
“People
say these requirements — no restaurants, no nonessential workers — are
burdensome,” he said. “And they are burdensome. But they are
effective, and they are necessary. The evidence suggests that they have slowed
our hospitalizations, and that is everything.”
Shown
the Kinsa data, Dr. Howard Zucker, New York state’s health commissioner, called
it “a great example of technology being able to show what we think we’re
experiencing — and it’s consistent with our data.”
On
Friday, the University of California, San Francisco, said its hospitals were
not facing a huge surge of patients and gave the credit to the strict
shelter-in-place orders imposed by Mayor London Breed on March 16.
On
Sunday, Washington state also reported a downward trend following the
imposition of its restrictions, based on data from deaths, coronavirus tests
and information about people’s movements from the Facebook apps on their
cellphones.
“People
need to know their sacrifices are helping,” said Inder Singh, founder of Kinsa.
“I’ve had friends text or call and say: ‘Inder, this seems overblown. I’m
sitting at home by myself, I don’t know anyone who’s sick, why am I doing
this?’”
Kinsa’s
tracking of fevers in Miami-Dade County in Florida showed an even more
pronounced trend, and the company had tried to raise the alarm.
In
early March, Florida beaches and bars were packed with spring break revelers,
despite warnings that crowding was dangerous. On Kinsa maps that normally look
for flu trends, fever levels were soaring.
Singh
tried to get the word out, but the San Francisco-based company is relatively
obscure and almost no one paid attention.
”It was
so frustrating,” said Nehru, the company spokeswoman. “For three days from
about March 19 on, Inder was calling local government folks in Florida, The
Tampa Bay Times and other papers. The government did absolutely nothing.”
“Plus,
we were getting pushback on social media,” she said. “People were saying, ‘The
testing doesn’t show this, you know, is your data wrong?’ and ‘Could it be that
you were just selling more thermometers in Florida?’”
On
March 12, a state of emergency had been declared, but according to Kinsa’s
data, fevers were continuing to rise. Closing local schools on March 16 had
little effect.
But on
March 18, Miami’s bars and restaurants were closed, and within two days reports
of fevers started to drop sharply, according to Kinsa’s data.
But the
damage may have been done. Now Florida is reporting that coronavirus cases are
soaring, and its hospitals expect to be overwhelmed.
The
dropping fever trend does not mean cases or hospitalizations will also drop
immediately, Nehru pointed out.
Confirmed
cases will keep going up for days, because people do not always go for a
COVID-19 test the same day they feel feverish. Besides, many states are doing
more tests every day.
The CDC
has declined to comment whenever it is asked about the company.
Singh
said he had approached the CDC about using his data as part of its own flu
surveillance, but agency officers had insisted on him giving up the rights to
his data if they did, and he refused.
Schaffner,
an adviser to the CDC on flu surveillance, said he was disappointed to hear
that and would look into it.
The
refinement Kinsa made on March 22 was to add “trends” — a map showing whether
all fevers were increasing, decreasing or holding steady.
“Finally,
people are asking us for our data,” Singh said Monday. “We’re talking with six
states about them distributing more thermometers. People understand the value
now.”
This
article originally appeared in The New York Times.
© 2020
The New York Times Company
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