A cyclosporiasis outbreak caused by a parasite has spread across at least 31 US states, infecting over 400 people in New York City alone, with CDC and health authorities still trying to pinpoint the source though salad greens and lettuce are emerging as leading suspects. The outbreak is expected to continue through August, making it a significant public health concern requiring careful monitoring of the food supply chain. Most cases emerged in the last 10 weeks, indicating rapid recent spread that health officials are racing to contain.