New cases in China are now declining thanks to the government’s dramatic measures to contain the virus — mainly case finding, contact tracing, and suspension of public gatherings — as WHO epidemiologist Bruce Aylward, who led a recent mission there, told my colleague Julia Belluz.
In the US, there’s still time to put those efforts in place to flatten that curve.
In Washington state, health officials are now asking community groups to cancel events that bring together more than 10 people, and are recommending that people telework if they can. Pregnant people, people older than 60, and those who have underlying health conditions are being asked to stay home. More states and communities may have to impose such measures in the coming weeks. So be prepared for them.
“We also need to stop panicking and stigmatizing people of different ethnicities— this will only make people more hesitant to speak out and seek care,” says Abraar Karan, a physician at Brigham and Women’s Hospital and Harvard Medical School. “Disease should show us that we are all connected and need to help each other, not divide us.”
Individuals can help slow the spread of the virus through measures like staying home when you feel just a little bit sick (even when it is inconvenient), washing hands often, and following public health official recommendations when it comes to avoiding large crowds of people.
That’s the optimistic take: We will slow the spread, and help out our communities and the most vulnerable in the process.
The pessimistic view: Because of the lag in testing, the outbreak might be further along — and therefore harder to contain — than authorities currently realize. “There certainly is a window to [impose social distancing measures], but whether or not we’re still in that window, we have no idea because we have no idea what’s happening without the testing,” Grubaugh warns.
The lucky scenario: Covid-19 naturally stops spreading as fast during the summer
Another factor that could potentially slow the spread of coronavirus is the changing of the seasons.
For a variety of reasons, some viruses — but not all — become less transmissible as temperatures and humidity rise in the summer months. The viruses themselves may not live as long on surfaces in these conditions. Also, human behavior changes, and we spend less time in confined spaces. “A lot of how the outbreak ends or at least how things progress in the next few months really depends on if this is seasonal,” Grubaugh says.
That’s still a big unknown. “Just because some respiratory diseases, like flu, demonstrate seasonality doesn’t mean that Covid-19 will,” Maimuna Majumder, a Harvard epidemiologist, says. She and colleagues recently published an early version of a paper (which has not been peer-reviewed) that found that changes in weather across China did not seem to impact the course of the outbreak.
The study suggests that humidity — which appears to be correlated with the seasonality of the flu — is not correlated with transmissibility of Covid-19, she says. (She also stresses to treat the data as “provisional,” and that her group is still studying the potential effect of temperature on transmissibility.)
But if it is seasonal, it doesn’t mean Covid-19 goes away after the summer. “It likely isn’t just going to magically go away,” Grubaugh says. “Next winter might end up being the big winter.”
And if it is seasonal, it’s still dangerous. It would be like the flu, “except potentially with a higher case fatality rate,” Rasmussen says. “Which is definitely a problem because the seasonal flu kills 30,000 to 60,000 Americans every year. And even if it’s the same case fatality rate of seasonal flu, that still presents a substantial public health burden.”