The Centers for Disease Control and Prevention last week issued interim guidelines for U.S. health care providers caring for pregnant women who recently traveled to areas with Zika virus transmission. Among other actions, CDC recommends testing pregnant women for the virus if they report at least two related symptoms within two weeks of travel to affected areas, or have ultrasound findings of fetal microcephaly or intracranial calcifications. 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. Until more is known, pregnant women should consider postponing travel to areas with ongoing Zika virus transmission, CDC said. 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).