Study shows that high levels of testing could drive COVID-19 to 'extinction,' but there's a catch
Yesterday in Wyoming, 77% of tests for COVID-19 came back positive. That could just be a fluke, except that it’s the first day in a week that Wyoming’s test results have fallen below 90%. Thankfully, no other state is proving quite that inadequate at the moment—despite Mississippi, Iowa, and South Dakota giving it a mighty try—but there is no doubt that the United States is still doing a woefully inadequate job of testing, and that testing is vital to ending the coronavirus pandemic.
To prove that, all it takes is looking at the other end of the Johns Hopkins testing chart. Repeatedly, states have used high rates of testing to identify and isolate cases of COVID-19, as a means of combating the disease. A good example right now would be North Dakota. In the last two weeks, the rate of testing has soared to 11.8 tests per 1,000 residents. Even at that high rate, the state’s rate of positive tests is still nearly 15%—about 5 times what genuinely adequate testing should return. But a week ago, North Dakota was consistently seeing positive rates over 50%. And since it has upped its rate of testing and tracing, America’s most COVID-saturated state has seen a significant decline in new cases.
But even states with the highest rate of testing at the moment are only doing a small fraction of what needs to be done to genuinely crush the pandemic. And a new paper from Harvard shows what so many nations knew from the start — a massive testing program generates even larger benefits.
At the moment, the state doing the highest level of testing is Rhode Island, which on Friday hit a rate of 13.6 tests per 1,000 residents. States have reached number several times that value when battling a regional spike, while those few states that have managed pandemic well—such as Vermont and Hawaii—have varied their testing rate as they’ve kept the number of positive results below 3%.
When looking around the world, some other testing rates don’t at first seem all that impressive. For example, South Korea has done fewer than 3 million tests total. That means their rate of testing is almost 10 times lower than in the United States. However, South Korea has done a program of highly directed testing and case tracing that hit infected areas hard as soon as outbreaks began, and traced down all possible contacts quickly. That system has allowed South Korea to get on top of each new outbreak when it occurs and rapidly suppress the number of cases before it becomes a general epidemic.
At the other end of the scale, Iceland went big. They set a goal of testing everyone, and were well along the road toward achieving it when they got the case count down to the point where they could address the issue with more limited testing. The tiny Faroe Islands, population 49,000, did Iceland one better. They’ve tested everyone there at least three times. Not surprisingly, their case count has been … pretty small.
But what researchers from Harvard’s School of Public Health and the University of Colorado Boulder team are suggesting is testing of a whole different order. Like testing half the population of the United States every week. Repeatedly. That’s like all the tests done to date, every week.
However, before you start thinking about how infinitely long the testing queue in L.A. would be under this kind of scheme, what the Harvard team is talking about is not the kind of testing where you roll your car up to a clinic or technician to explore just how close someone can get to your brain by inserting a cotton swab into your nose. A critical part of the proposal is that this would be cheap and rapid tests, self administered, that return nearly instant results.
This kind of test is already available, but there have been big concerns over the rate of both false positives and false negatives these tests can generate. But the new study says … that’s okay. Because, in terms familiar to military planners, quantity has a quality all its own.
“Our big picture finding is that, when it comes to public health, it’s better to have a less sensitive test with results today than a more sensitive one with results tomorrow,” said lead author Daniel Larremore.
One of the goals of this study was to generate a response that could be not just self-testing, but self-policing. People who receive a positive test could place themselves in quarantine, and if the level of testing was massive enough, the need for a centralized authority coordinating test results and contact testing evaporates. Because if people just do the right thing … and … and ….
Yes, that would definitely be the point where the numeric analysis of the paper seems to smash its nose right into the wall of what we’re seeing on the streets every day. This is the nation where people are not only shoving over stands in their low grocery to protest having to put on a mask, they’re watching as Donald Trump and a long line of other Republican politicians absolutely refuse to give a straight answer about when they first received positive test results for COVID-19. While it’s absolutely certain that a very high rate of testing would more than compensate for the kind of single-digit inaccuracies in the results of these quick tests, it’s very much not certain what would happen if 20, or 30% or 50% of the population simply refused to go along with the testing, or worse, refused to isolate when receiving a positive result.
On paper, the kind of mass testing the researchers describe would absolutely crush the pandemic in short order.
In one scenario, in which 4% of individuals in a city were already infected, rapid testing three out of four people every three days reduced the number ultimately infected by 88% and was “sufficient to drive the epidemic toward extinction within six weeks.”
But if that rapid testing requires that people practice responsible self-policing … it might as well involve a national distribution of unobtanium.
Still, widespread use of quick test paired with expanded oversight, mask mandates, and coordinated contract tracing definitely could have an impact on the pandemic, even in the time between the start of Biden’s term and general availability of vaccines. A packet of quick tests, and a six pack of masks sent to every home in America could be just the national shot we need, before we can all get a shot that’s more personal.