What is the fine-grained topic of the following text: MONDAY, Aug. 13, 2018 (HealthDay News) — The number of confirmed cases of a parasite-caused illness linked to McDonald’s Fresh Express Salad Mix is now 436 in 15 states, the U.S. Centers for Disease Control and Prevention says. Only return the topic.
Outbreak of parasite-caused illness linked to McDonald's Fresh Express Salad Mix.