“These aren’t just any random chemicals that can be mixed together,” Streeck says. “We need enzymes that are produced through biological processes by cells or yeasts. Such complex processes “can’t be ramped up at will on short notice.” Manufacturers, some of which are based in the U.S., are currently receiving inquiries from all over the world.
But the biggest bottleneck at the moment isn’t even due to the lack of reagents, with which the genetic material of the coronavirus can be specifically detected, says Hendrick Borucki from the Bioscientia laboratory network. There’s also a shortage of the substances that can be used to break open the virus envelope and isolate the genetic material for the actual test. Other laboratories complain that even plastic pipettes or carrier plates that are calibrated for the analytical instruments are becoming increasingly difficult to obtain.
There is a danger that the lack of reagents could soon mean that fewer tests will be available than there are today. Meanwhile, the number of infections is expected to continue increasing.
To manage the looming shortage, lab operators have called for an even stricter decision-making process for who gets tested and who doesn’t. Only people who are at risk or showing symptoms should be tested, they argue. “At the moment, we’re still testing way too many healthy people,” says Borucki. Well over 90 percent of the tests evaluated by Bioscientia come back negative. “We’re wasting valuable reagents.”
The Robert Koch Institute now feels the same way. “We don’t have enough tests to be able to use them senselessly,” the institute’s director, Lothar Wieler, warned last week. At the same time, though, the institute has loosened the recommendation that has thus far been in place – namely that patients with symptoms should only be tested if they had contact with an infected person or had been in a region with a high number of confirmed cases. Given that the pathogen is now essentially everywhere, the focus on at-risk regions no longer makes sense, an institute spokeswoman said.
Limiting tests to people showing symptoms is a matter of some disagreement among experts. “We know of cases where the test returned a positive result even though the test subject was showing no symptoms at all,” says Streeck, the virologist. A study from Hong Kong found that as many as 40 percent of the infections took place in the phase before symptoms developed, Streeck says. These virus carriers who have no symptoms can spread the pathogen and unwittingly endanger others, he adds.
The rule is also inscrutable for many of those affected. “We didn’t have any symptoms, but we were concerned,” says a 45-year-old mother from Hesse. The father of her two sons had been in the Austrian ski resort of Ischgl with friends, and after he returned home, the boys spent a weekend with him. Soon thereafter, Ischgl was declared a high-risk area for the virus and the father and five of his friends all tested positive for the virus. The mother contacted their family doctor, who referred them to the health authorities. There, she was told that tests would only be performed if she or the children developed symptoms. “We wanted peace of mind, so we fibbed,” the woman admits. Together with her children, she drove to a test center set up in front of a hospital in Worms and said she had a slight fever.