As many as 140 women and newborn babies at Swedish Medical Center/First Hill in Seattle may have been exposed to whooping cough, as an employee was recently diagnosed with the illness. Hospital officials are warning patients, physicians, and staff members who had contact with the hospital's Women and Infants Center employee between March 15 and 18 or on March 22 to receive an antibiotic to ward off the disease, says Will Shelton, the hospital's manager of epidemiology. Shelton did not give the employee's name to protect her privacy but did provide a number that concerned people can call to determine if they had contact with the employee. Whooping cough, or pertussis, is potentially fatal to infants who have not been completely vaccinated against the illness; however, adults who contract the disease often do not notice the symptoms, which means they can spread the illness to others without knowing it. A whooping cough immunization is required before children enter school or day care in Washington State, and health officials recommend vaccination against the contagious disease before two years of age.