The U.S. Centers for Disease Control and Prevention (CDC) reported that there have been problems with some of the 2019-nCoV test kits sent out to labs in states and said that it likely needs to remanufacture reagents.
Test kits have been provided to qualified labs in the U.S., including state and local public health laboratories, through the CDC's International Reagent Resource, following the issuance of an emergency use authorization by the Food and Drug Administration. The plan was that each lab requesting the test would get one diagnostic panel, which could test 700 to 800 specimens.
Labs need to validate the tests before use, and some have reported to the agency that they obtained inconclusive results during this quality control process.
It appears that a reagent wasn't performing as consistently as it should be, and, consequently, the agency believes it will need to remanufacture some reagents, explained Dr. Nancy Messonnier, director of the CDC's National Center for Immunization and Respiratory Diseases, during a press briefing on February 12.
Until results from every state are in, the CDC will not know which labs can move forward and which need new reagents, she explained.
"We are working closely with them to correct the issues," Messonnier said.
The agency rushed to get the test kits out and "hoped everything would go smoothly," with every state up and running for testing this week, but at the same time quality control is very important, she said at the briefing.
In addition to U.S. states, CDC coronavirus diagnostic kits have been shipped to more than 30 countries. Each country has its own internal validation process, and it's unclear how many have completed this work and started using the tests, according to Messonnier.
As of February 12, a total of 45,171 cases of coronavirus disease (COVID-19) had been confirmed globally, including 13 in the U.S., according to a situation report from the World Health Organization.
An unfortunate mishap at CDC
In addition to the problems with kits sent out to labs, there was a mistake with the testing processes at the CDC's own labs. The University of California, San Diego Medical Center discharged four evacuees who had come from China and been quarantined, believing that they were all negative for the coronavirus based on information from the CDC. In fact, the results were not yet in for one of the patients, who tested positive for COVID-19, the new name for the disease caused by the virus.
The "mishap was unfortunate," but the agency has added quality controls to prevent such mistakes from happening again, Messonnier said.
The CDC advises testing for people with symptoms of respiratory illness and who have traveled to regions that were the source of the outbreak or come in contact with a confirmed case. To date, more than 30,000 passengers coming from affected regions have been screened at airports.
"Our goal is to be as least restrictive as possible, while ensuring the safety and health of all Americans," she said.
Meanwhile, the agency is working on a test that could be used to detect the coronavirus in people who are asymptomatic. The CDC is gathering specimens from patients in the U.S. to understand the immune response, and once it has completed this process, it will make a test available rapidly -- within three or four weeks, Messonnier added.