The tally of people infected with the coronavirus after attending a high-profile Centers for Disease Control and Prevention conference in April has risen to at least 181, the agency reported Friday. No one was hospitalized.

The CDC’s Epidemic Intelligence Service officers and alumni — the disease detectives deployed to identify and fight outbreaks — met April 24-27 at an Atlanta hotel. The conference drew 1,800 in-person attendees, the first in-person Epidemic Intelligence Service gathering in four years. Like many conferences, it was crowded, with much face-to-face contact, many events held in small rooms and lots of socializing, according to attendees. About 70 percent of participants who responded to a CDC survey said they did not wear masks at the event.