The Ebola virus might have struck again on American soil.
One scientist in Atlanta may have been exposed to the virus and as many as 12 others are being assessed for potential exposure, agency officials said on Wednesday according to The Washington Post.
The exposure took place Monday at a high-security lab of the Centers for Disease Control and Prevention where scientists have been conducting research on the virus.
A sample containing the potentially infectious virus was mistakenly put in a place where it was transferred for processing to another CDC lab, also in Atlanta on the CDC campus.
The technician has no symptoms of the illness but will be monitored for 21 days, the incubation period of the disease, according to the Washington Post.
A small number of other employees, fewer than a dozen, who entered a lab where the mistake occurred will also be assessed for exposure, according to The New York Times.
The first case of Ebola was diagnosed in the U.S. in October when Liberian Thomas Eric Duncan flew to Dallas. He passed away on Oct. 8.