Knowing where the virus is spreading is key to relaxing social distancing and returning to normalcy, Buckee said.
In addition to different parts of the country seeing different disease curves, there are “important epidemiological timelines here where when you become infected you’re spreading the virus, but you don’t show any symptoms for about five days or so,” Buckee said. “For people who end up in the hospital, that takes another week and then disease progression from there to death takes another week or more,” she added.
“So, there’s a long time lag between when people are becoming infected and when we’re starting to see an uptick in deaths. And I think that really highlights the important problem here of lack of test capacity. This has a been a problem from the beginning and it continues to be patchy,” she said.
The lack of testing capacity is a big problem because the disease has “a very broad clinical spread,” Buckee said. So even as people show up at the hospital and get tested, there are many more cases in the community, including mild and asymptomatic cases that go undetected.
“And those are the people that are spreading the disease. Right now, we don’t have good estimates for where we are on the epidemic curve in different places,” said Buckee.
“So discussions of relaxation of physical distance, which do seem to be having an effect, curbing some of the worst impacts of the outbreak, need to be based on the capacity to test people so we know where we are.”
Buckee added that without knowing the answers, the nation could reopen too soon and risk a deadly second pandemic wave.
“Right now, we don’t have good estimates for where we are on the epidemic curve in different places. So, discussions of relaxation of physical distance, which do seem to be having an effect, curbing some of the worst impacts of the outbreak, need to be based on the capacity to test people so we know where we are,” she said.
There are two types of tests: one that looks for actively circulating virus and another that tests for antibodies to the virus, an indication a person has been infected at some time in the past.
“Until we know how far along the epidemic curve we are, we can’t really make informed decisions about opening up and how to do that in sensible way because we simply don’t know whether we’re close to the first peak or not,” Buckee said.
“We could see a second wave that could be even more deadly. So really understanding where we are in the epidemic curve, which will be different in different places, is where we’re at. And I think, again, the call for testing is the most important.
“We were very clear in the guidelines that we believe we can monitor, again, monitor communities at the community level,” she said.