The risk to the US from an unconfirmed pneumonic plague case in Siberia is extremely low, the CDC's director said, and the agency is prepared to monitor and screen travelers ↧ CDC sees low plague risk, monitors Siberia arrivals after worker de... Centers for Disease Control and ​Prevention Director Erica Schwartz said on Wednesday the risk to ‌the US from an unconfirmed pneumonic plague case in Siberia was extremely low, but the agency was prepared to monitor and screen travelers.