Coronavirus testing still limited as labs rush to roll out their own versions

In response to blistering criticism about coronavirus testing in the United States, the government has loosened rules to allow public health labs and academic medical centers to design and use their own versions.

But gearing up may not happen quickly enough to contain the fast-spreading upper respiratory disease — and expanded capacity is complicating efforts to keep an up-to-date national tally of tests and cases.

The Association of Public Health Laboratories on Sunday estimated that its members — 125 state and local labs — could soon be doing 10,000 tests a day. The association was rebuffed last month after asking the Food and Drug Administration to do what it has now done, loosening rules for “emergency use authorization."

At the Hospital of the University of Pennsylvania, chief medical officer Neil Fishman said Monday that Penn has been working with several diagnostic testing companies to develop a test.

“I would guess validation would take two to three weeks, so we probably won’t have a test until mid-March,” he said.

By then, at least one commercial test may be available. Cepheid, a leading diagnostics company based in California, has said its coronavirus test — which will have automated components and run on a testing platform already installed in 23,000 sites around the world — will launch between April and June.

While expanded testing should improve disease surveillance, it could undercut the central role of the U.S. Centers for Disease Control and Prevention. On Monday, the CDC abruptly and without explanation postponed a scheduled news briefing and also removed data on its website summarizing how many people had been tested across the country.

“Now that states are testing and reporting their own results, CDC’s numbers may not represent all of the testing being done nationwide,” a CDC spokesperson emailed to explain the website change.

Pennsylvania’s state lab expects to be able to do testing by the end of this week, while state labs in New Jersey and Delaware are processing samples, according to state officials. Although none of the states has had a confirmed case, Delaware on Monday announced three negative tests, and two for which results were pending; New Jersey over the weekend tested three people who were negative for the virus, COVID-19.

In the U.S., more than 80 cases have been reported in at least 10 states. Four more people have died of the virus in Washington state, raising the death toll in the state and nation to six, health officials said Monday.

The nation’s first positive case was diagnosed in January in Washington state, where the virus has spread to a nursing home. Officials speculate that the virus was being transmitted person-to-person, undetected, in the Seattle area for weeks because of insufficient testing.

Until last week, the CDC narrowly defined which people with respiratory symptoms should be tested. It also shipped faulty test kits to state labs in early February. Only about 500 people had been tested in the U.S. by the end of February.

The polymerase chain reaction (PCR) technology being used for all coronavirus tests is standard in molecular biology. But obtaining or making the components — primers, probes, reagents — and validating the accuracy with patient samples is complicated. Under the loosened rules, the FDA is still requiring labs to validate their tests, but they will have an additional 15 days to submit a formal emergency use application.