CDC和卫生部官员在周五新闻发布会上说： tests could show negative one day, and positive on another Dr. Nancy Messonnier, director of the National Center for Immunization and Respiratory Diseases, said An initial negative test result for the virus doesn't mean a patient is "out of danger" for developing the disease or transmitting it to someone else days later.
加拿大最新的一例， 第一次test也是阴性。后来送到国家实验室测，测出阳性。说是国家实验室测试更 sensitive Chief Medical Officer of Health Dr. David Williams said the woman originally tested negative for the virus, however, after additional testing, he said she was found to be positive by the National Microbiology Lab. Williams said the national lab “uses a more sensitive test that can identify the smallest trace of the virus.”
因此隔离变得更加重要。
可能也解释了为什么，CDC的检测耗时，pending数量进展缓慢。
CDC和卫生部官员在周五新闻发布会上说：
tests could show negative one day, and positive on another
Dr. Nancy Messonnier, director of the National Center for Immunization and Respiratory Diseases, said
An initial negative test result for the virus doesn't mean a patient is "out of danger" for developing the disease or transmitting it to someone else days later.
日本
one person who came back on the first flight Wednesday initially tested negative but an additional test discovered the infection
https://mainichi.jp/english/articles/20200201/p2g/00m/0na/110000c
加拿大
A fourth person in Canada has the coronavirus, first testing negative, then positive
https://www.bloomberg.com/news/articles/2020-01-31/fourth-person-with-coronavirus-in-canada-first-tested-negative
中国
“A patient may be found as negative for the first or second test, and then found to be positive the third time,”said Jonathan Yu, a doctor at a university hospital in Wuhan
https://www.japantimes.co.jp/news/2020/02/01/asia-pacific/science-health-asia-pacific/china-virus-cases-undercounted/