Health officials in West Texas have started testing babies for tuberculosis after learning that more than 700 infants at an El Paso hospital were exposed to a worker who was found to have the disease. Local health authorities said the babies may have been exposed at a nursery in Providence Memorial Hospital of El Paso between September 2013 and last month. A health-care worker tested positive for TB last month. Officials used Centers for Disease Control and Prevention guidelines to determine how far back to test those who might have been exposed. Authorities are especially concerned about infants, because they are more likely to develop serious disease.