Please stop infecting each other. That’s the message Harvard University has for students after a mumps outbreak left 40 people sick over the past two months. The university first announced mumps cases in February, and infections have steadily increased despite efforts to isolate patients.

Paul J. Barreira, director of the Massachusetts university’s health services, told the student newspaper that the rise in cases is worrying. “I’m actually more concerned now than I was during any time of the outbreak,” Barreira told The Harvard Crimson. “I’m desperate to get students to take seriously that they shouldn’t be infecting one another.” FULL REPORT