Questions and criticism mounted Thursday about how an Ebola patient in Dallas could have been allowed to leave the hospital two days before he was suspected of having the virus—and about how well prepared the country is for future Ebola cases.

Public health officials are reaching out to as many as a hundred people who may have come into contact with the first Ebola patient to be diagnosed in the U.S., quizzing them about their interactions with the man, who has been identified as Thomas Eric Duncan.

Any who are found to have come within three feet of him are considered to have been in close contact and will be monitored over the next three weeks to ensure they don't