Testing for coronavirus is falling in around half of U.S. states, despite high case numbers and a high positivity rate being recorded in many of these regions. Ashish Jha, director of the Harvard Global Health Institute, told Newsweek this fall represents the "early cracks" in a system not designed to handle such high case numbers. He said in some states, testing is falling while cases are rising, meaning huge numbers of infections are being missed by health authorities.
The high level of testing in the U.S. has been touted as a major success by the government. In terms of numbers, the U.S. has carried out more tests than any other country in the world. This has been used by the current administration to explain why the country has so many cases of COVID-19, with over 4.8 million recorded—two million more than Brazil, the world's second worst affected country.
However, the number of daily tests being carried out is now starting to drop. According to Johns Hopkins University data, total testing in the country has fallen fairly steadily since the end of July. While the average test positivity rate has also been falling, it is still 7.6 percent for the U.S. as a whole.
Test positivity denotes the percentage of tests coming back positive from the total number carried out. According to advice from the World Health Organization, the test positivity rate should be 5 percent or lower for at least two weeks before a country reopens. Jha said that in some states, having test numbers fall is not an issue. In places like Vermont, case loads are so low that a fall in testing just shows the demand is not there. Vermont's test positivity rate is at 0.5 percent, according to Johns Hopkins. In other states, however, the fall in testing is a problem. In a small handful, testing is down but case numbers are up.
"Those are extremely unusual and very scary in some ways because if you're testing fewer people and finding more cases, then your percent positive is going way up," Jha said. "It's a real problem in the sense that you have large outbreaks and every day you're missing more and more."
In a larger number of states, both testing is down and cases are down—but not at the same rate. Where testing is down more than cases, the test positivity goes up, and that is a "really bad sign," Jha said.
"Ultimately for me the most important metric in all of this is the percent positive... Once you get above 10 percent it's hard to know exactly what proportion of cases you're missing but you're probably missing 60 to 80 percent of cases out there, once it's above 10 percent. And a vast majority of states where testing is down that is the case."
At present, there are 38 states that have a test positivity rate above 5 percent. Some of the highest rates currently being seen are in Mississippi, Nevada, Alabama, Florida, Arizona, Idaho and Texas.
"At this point in the pandemic, we should not be seeing testing coming down in almost any state," Jha said. "There's so much more testing that needs to be done. The fact it is dropping in half the states in the United states is a real problem because it means that our testing infrastructure is starting to fail and I see this as the early cracks in a system that wasn't designed to manage this level of cases."
There are a number of issues that are resulting in the fall in testing. Jha said one of the problems is laboratory machines processing the tests are starting to break down as they were not designed to run at the pace they are. Staffing of labs is also becoming a problem. These factors mean there are delays in processing tests, so people are not getting their results for days if not weeks. As a result, people are just not bothering to get tested.
Folks are saying it's not worth it," Jha said. "And they're right on some level, it is important to get a result back [quickly] that you have to pay hundreds of dollars for. It makes no sense."
Jeffrey D. Klausner, Professor of Medicine at the University of California, Los Angeles, also said reductions in state and local spending on testing may be behind the fall in some areas.
"There was a promise that testing costs would be covered with federal funds but many states and cities have not seen those funds and they are not certain that they will be reimbursed," he told Newsweek in an email.
Klausner said the biggest problems with the testing system relate to the lack of infrastructure, gaps in the supply chain and an absence of information technology infrastructure within public health programs.
"Other problems include the fact that the FDA is completely overwhelmed and months behind now in emergency reviews. States were given the option to take on that review process but few have set up their own review programs."
With fewer tests, it may seem President Donald Trump's argument that the high level of testing being behind the high case numbers could start to fall apart. Jha does not think this is the case, however. "In some ways this is what the president has been looking for. Numbers are coming down," he said.
"The bottom line is that testing is dropping in the U.S., but probably not enough for the president to stop [using] it. He will use the total amount of tests done. And that will remain high in the U.S. for a long time. They'll find a way to convince themselves things are great in America even though pretty much everyone knows things are not great in America."
Correction 08/07 6.52 a.m. ET: Jeffrey D. Klausner's title and affiliation have been corrected.