As coronavirus continues to spread across the world, a simple solution has been repeated by some leaders: Warm summer temperatures will stop the outbreak in its tracks.
U.S. President Donald Trump floated the idea that by
April the coronavirus problem would solve itself. He told a crowd at a
Feb. 10 rally in New Hampshire: “You know, in theory when it gets a
little warmer, it miraculously goes away, that’s true.”
In Southeast Asia,
officials in Indonesia have offered the warm climate as the reason that
no cases have been diagnosed there. “Indonesia’s air is not like the
air in China that is subtropical,” said Achmad Yurianto,
a senior official in Indonesia’s health ministry, in response to a
study suggesting there are likely to be undetected cases in the country.
However, infectious disease experts say
while the factors that cause other viruses to retreat during the summer
months could affect this coronavirus, called COVID-19, in a similar way,
there’s no way to be sure. And, even if the virus’ spread does slow as
temperatures rise, that doesn’t mean it will be gone for good.
Why cold and flu decrease in the summer
There’s precedent for the idea that the COVID-19 outbreak will collapse with the onset of summer.
The common cold is most prevalent in the winter and spring, and influenza is most common during the fall and winter in the U.S., with flu activity peaking between December and February, according to the CDC.
It appears that COVID-19
is transmitted in the same fashion as the flu and common cold: by close
contact with infected people and from respiratory droplets when an
infected person sneezes or coughs.
There’s a variety of reasons that influenza and cold
infections plummet in the summer, but a major one is that that warm,
humid weather can make it harder for respiratory droplets to spread
viruses.
“The droplets that carry viruses do not stay
suspended in humid air as long, and the warmer temperatures lead to more
rapid virus degradation,” says Elizabeth McGraw, director of the Center
for Infectious Disease Dynamics at Pennsylvania State University.
Human activity also changes in summer months, says
Thomas Bollyky, the director of the Global Health Program at the
Washington D.C.-based Council on Foreign Relations. People spend less
time indoors—where they tend to be in closer contact with each other,
making it easier for the virus to spread—in the summer.
But health experts aren’t so sure that COVID-19, which has infected more than 83,000 people since officials first discovered the disease in December, can be stopped by the onset of summer.