While infections have been reported across multiple states, officials have not identified one confirmed cause behind the recent rise. Unlike some stomach illnesses, Cyclospora infections can last for weeks if untreated and may return after symptoms appear to improve. Which States Have Reported Cyclospora Cases? Health departments across the United States have recorded Cyclospora infections in multiple states during the 2026 outbreak monitoring period. Investigation Continues as Cases RiseAs more states continue reporting infections, health officials are focused on identifying patterns that could reveal the source of the outbreak.