The Centers for Disease Control and Prevention yesterday issued interim guidelines for U.S. health care providers caring for infants born to mothers who traveled or lived in an area with Zika virus transmission during their pregnancy. A marked increase in infants born with microcephaly, a birth defect resulting in smaller than normal head size, has been reported in the Zika outbreak in Brazil. It is not known how many of the cases are associated with the virus. Only about one in five people infected with the mosquito-borne virus will get sick, and their illness is usually mild. The most common symptoms are fever, rash, joint pain or conjunctivitis (red eyes). For more information, visit www.cdc.gov/zika.