The mumps outbreak is slowing in Iowa, but officials at the state’s blood banks are still carefully screening every donor. Blood centers will not take donations from people who might have an infectious disease like mumps.

Susan Miller, a medical technologist at Mercy Hospital in Cedar Rapids says, “Of course, you wouldn’t want that to get into the units and spread to people who are being infused with blood who have other complications to begin with.” She says if a patient received blood from a donor who had mumps, the result could be disaster.

But according to most blood center rules, if you’ve had mumps you must be symptom-free for at least one week before they’ll allow you to give blood. You have to wait two weeks after having the measles/mumps/rubella vaccination to give blood. And you have to wait three weeks if you haven’t had the vaccination.

Nancy Mathahs, director of Mercy’s laboratory services, says she’s not worried about mumps getting into the blood supply because most of Iowa’s mumps cases have been in college-aged kids and there aren’t many regular blood donors in that age group. “A lot of those people were in an age group that don’t usually donate unless they do college type drives and so I think the blood supply is safe,” she says.

Blood bank workers say when cases of another infectious disease are reported, they’ll take similar precautions.