During the previous six years, one to three cases per year of Kawasaki syndrome had been reported by a state health department. During the past 3...

During the previous six years, one to three cases per year of Kawasaki syndrome had been reported by a state health department. During the past 3 months, 17 cases have been reported. All but two of these cases have been reported from one county. The local newspaper carried an article about one of the first reported case, a young girl. Describe the possible causes of the increase in reported cases.