Nancy Messonnier, head of the respiratory disease section at the Centers for Disease Control and Prevention, said around 100 people in 26 states are being investigated for the virus, which originated in the Chinese city of Wuhan.

Of the confirmed cases, all five people had traveled to Wuhan, Messonier said during a conference call with reporters.

“Every case we have had in the United States is someone who has had direct contact in Wuhan,” she said.

Messonier said there are two cases in California and one each in Arizona, Illinois and Washington state. Until now the toll was three.

While Chinese officials have launched an extraordinary emergency response, Messonier insisted that the health risk for Americans, in general, remains low “at this time.”