Some of the coronavirus testing kits sent to state laboratories around the country have flaws and do not work properly, the Centers for Disease Control and Prevention said on Wednesday.
The kits were meant to enable states to conduct their own testing and get results faster than they would by shipping samples to the C.D.C. in Atlanta. But the failure of the kits means that states still have to depend on the C.D.C., which will mean several days’ delay in getting results.
The C.D.C. announced last week that it had begun shipping about 200 kits to laboratories in the United States and roughly 200 more to labs in other countries. Each kit can test about 700 to 800 specimens from patients, the agency said.
But the flaw was actually discovered, C.D.C. officials said, before the kits had been shipped overseas. Dr. Nancy Messonnier, director of the National Center for Immunization and Respiratory Diseases, had said during a news briefing Wednesday morning that the international shipments had been sent, but later in the afternoon said she was mistaken and the test kits had not been distributed to other countries.
Officials have not said how many of the kits are flawed.
On trial runs in some states, the kits produced results that were “inconclusive,” Dr. Messonnier said at the news conference on Wednesday.
“Things may not always go as smoothly as we may like,” Dr. Messonnier said.
She said the C.D.C. was working closely with the states, and would send out new ingredients to laboratories that have encountered the problem.
There have been 13 confirmed cases of the infection in patients in the United States so far. About 850 evacuees have been quarantined at military bases after returning from China. Still others are under self-quarantine at their homes.
The flawed test kits are a separate issue from the mislabeled samples in San Diego that led officials to discharge from the hospital a woman who was sick from the coronavirus.
More than 1,100 people have died, nearly all of them in China, where there are more than 44,000 confirmed cases.