Nearly 9,300 U.S. health care workers contracted COVID-19, and 27 have died. A majority of those who tested positive (55%) think they were exposed while at work. The Centers for Disease Control and Prevention has released preliminary data on infections among frontline health workers. Nearly three-quarters are women and more than a third had some underlying health condition. The median age is 42. About 8% of those who tested positive didn't have symptoms. And the majority (90%) didn't have to be hospitalized. But as many as 5% did require intensive care. A third of the health care workers who died were over 65 years old.