A serious infection transmitted from mother to fetus during pregnancy has been discovered for the first time in a nonhuman primate. The infection, cytomegalovirus, causes neurological impairment in about 25 percent of human infants who contract it in utero from their mothers. According to the Centers for Disease Control and Prevention, about 5,000 children a year sustain permanent injury from these infections, including deafness, blindness, seizures and cognitive delay. New research, appearing in Proceedings of the National Academy of Sciences, shows that rhesus monkeys, like humans, can pass the virus to unborn offspring through the placenta. The finding may help scientists develop a vaccine to protect against the infection.