Dutch looking to expand coronavirus blood testing; Nasal swab capacity is "enough"

With reporting by Jamie de Geir.

Laboratories in the Netherlands have the capacity to do 17,500 coronavirus tests per day, as cabinet ministers and health authorities previously told parliament, but this only involves polymerase chain reaction (PCR) tests, in which swabs of a patient's nasal and throat mucus are tested, the RIVM confirmed to NL Times. The health authorities want to conduct more serological tests, where the blood is examined for a prior infection, but they are still investigating how to do so efficiently and accurately.

PCR tests are used to test whether a patient currently has the coronavirus by detecting the genetic material of the virus, but they do not necessarily detect a prior infection in a patient who has since recovered. Serological tests, on the other hand, are used to test whether someone has had the virus in the past by checking for antibodies in the blood.

A main factor in testing capabilities, is the reliability of the tests. "The PCR tests are generally acceptable. They are all subject to quality requirements, there are no doubts about that," a spokesperson for the RIVM said to NL Times. But that is not yet the case for the rapid blood tests. "The quick tests are actually very unreliable," the spokesperson said. "Research is currently being done into more efficient serological testing and those studies are still ongoing."

"So far, none of the rapid tests examined are suitable for diagnosis in individual patients or for home use," the RIVM also notes on its website.

Two weeks ago a laboratory in Germany offered to do 5 thousand coronavirus tests per day for the Netherlands, but the Dutch authorities have not yet made use of this offer. A spokesperson for the Ministry of Public Health, Welfare and Sports told NL Times that this is because the Netherlands does not need extra PCR testing capacity at this stage.

Feike Sijbesma testified in Parliament on Thursday about test capacity in the Netherlands. The country's specially-appointed envoy for such issues said the biggest obstacle is still the shortage of good test material on the world market, which includes buffer solution, swabs, and Petri dishes. "About all other countries have the same problem. The manufactures say: 'You are really not the only one mister Netherlands'," he said in the Tweede Kamer, the lower house of Dutch parliament.

The Netherlands has been busy with solving this problem by manufacturing these supplies in the Netherlands, first by acquiring a buffer solution recipe from pharmaceutical firm Roche, then by beginning production of 3D-printed swabs. The Dutch authorities are still trying to locally-source more Petri dishes.

"We have enough testing capacity in the Netherlands for the time being, we are keeping the lines open, but it is not necessary for now," the spokesperson said.

The Netherlands is currently performing a maximum of between seven and eight thousand PCR coronavirus tests per day, mainly for healthcare workers and vulnerable patients. That is set to increase to a maximum of 10 thousand per day next week, with municipal health services GGD stepping in to conduct more tests.

The increased PCR testing is so that teachers and child services workers, as well as other care providers, can also be tested when primary schools reopen on May 11.