(Reuters) - Several U.S. states said new coronavirus test kits did not work, while others said they were reliable as the United States tried to speed up testing for virus cases, which rose to 14 on Wednesday.

FILE PHOTO: The ultrastructural morphology exhibited by the 2019 Novel Coronavirus (2019-nCoV), which was identified as the cause of an outbreak of respiratory illness first detected in Wuhan, China, is seen in an illustration released by the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, U.S. January 29, 2020. Alissa Eckert, MS; Dan Higgins, MAM/CDC/Handout via REUTERS

The U.S. Centers for Disease Control and Prevention (CDC)said some of the kits sent to U.S. states and at least 30 countries produced “inconclusive” results due to a flawed component and the CDC planned to send replacement materials to make the kits work.

Since late January, the CDC has rushed to distribute the kits to allow states to do their own, faster testing rather than ship all samples to CDC headquarters in Atlanta.

Accelerating the speed of tests, which can be delayed by days if sent to Atlanta, is important given the agency’s expectation the virus at some point is likely to start spreading within U.S. communities.

It was not clear how many kits were flawed. Of six U.S. state health departments that responded to Reuters requests for comment, half of them, including California and Georgia, said they were waiting for a replacement component for kits to make them work.

Other states, such as Illinois, said kits had produced accurate results and they were now doing their own testing.

The problem is likely reagents, or enzymes, needed to carry out the tests, Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases told a press conference.

“Things may not always go as smoothly as we may like,” said Messonnier.

The test issues came up as scientists from the United States and other countries tried to get access to data to validate reports suggesting the number of new cases of the virus in China has been dropping.

Messonnier said the CDC had not yet been invited to send experts to China as part of a World Health Organization (WHO) team to investigate the outbreak that has killed more than 1,100 people.

In San Diego, California, a second person evacuated from Wuhan, China, to a U.S. Marine base was diagnosed with the virus, raising the U.S. tally to 14, the CDC said.

The patient was among 232 individuals placed under quarantine at the base after being airlifted from the epicenter of the coronavirus outbreak. Another case of coronavirus was detected on Monday among the same group of evacuees.

Messonnier cautioned that at some point the United States was likely to see “community spread.”

“[We] can and should be prepared for this new virus to take a foothold in the U.S.,” she told reporters on the call.