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.
CDC's director of the Center for the National Center for Immunization and Respiratory Diseases, Dr Nancy Messonnier issued a calm but stark warning.
Officials have not said how numerous kits are flawed.
"Things may not always go as smoothly as we may like", noted Dr Messonnier. After being taken to Rady Children's Hospital for testing, CDC officials said the child's tests came back negative and the child was allowed to return to MCAS Miramar with the "evacuee population" that is under quarantine.
She said CDC is working closely with states, and will deliver new ingredients to laboratories that have encountered the problem.
Hundreds of people, including U.S. State Department employees and their families, have arrived at military bases in California, Texas and Nebraska aboard chartered flights from Wuhan, a city of 11 million that is the epicenter for the virus.
A second person evacuated from Wuhan, China, to a US Marine base near San Diego has been diagnosed with the coronavirus, raising the tally of confirmed cases in the United States to 14, the Centres for Disease Control and Prevention (CDC) reported on Wednesday (Feb 12).
LabCorp also said it had seen minimal impact to its business due to the outbreak, particularly in China, where the usually week-long Lunar New Year holiday was extended by 10 days in much of the country amid mounting alarm over the epidemic. Of the total confirmed cases, mainland China accounts for 59,539, while 1,361 of deaths are also on mainland China.
Japan's health ministry says 44 more people on a cruise ship quarantined in the port of Yokohama, near Tokyo, have tested positive for the virus that causes the new disease known as COVID-19.
So far, there have been just two known cases of human-to-human transmission in the USA but, after hopeful signs the outbreak might be subsiding, China Thursday reported a huge surge of more than 14,000 new cases.