Michigan has recorded 2,640 cases of cyclosporiasis as of Monday, a jump of more than 1,000 infections since Friday, making it the hardest-hit state in a national outbreak that now spans 31 states. The Centers for Disease Control and Prevention has confirmed 843 domestically acquired cases since May, with 86 hospitalizations and no deaths, but acknowledges an additional 1,500 suspected cases await laboratory confirmation. Viewed from state health departments, the true tally is far higher because federal confirmation lags by up to six weeks.

The parasite Cyclospora cayetanensis causes watery, often explosive diarrhea, severe fatigue, and abdominal cramps, with symptoms appearing roughly one week after ingestion of contaminated food or water. It does not spread directly between people. Michigan’s chief medical executive stated that early investigation information points to lettuce as a common product, though no specific grower or supplier has been identified and other foods cannot be ruled out. The state has advised consumers to avoid pre-packaged salads, discard outer leaves of lettuce heads, and wash produce thoroughly.

In Quebec, 85 cases have been reported since the start of 2026, compared with 30 over the same period in 2025. The provincial health ministry attributes the majority to travel, primarily to Mexico, and says no cases are currently linked to the US outbreak. A retired food safety professor noted that the parasite is more commonly acquired during travel than from Canadian produce, but the ministry is monitoring the situation closely given mandatory national reporting.

Other health and environmental incidents are drawing attention across North America and Australia. A paper in the Canadian Medical Association Journal urges physicians to consider anaplasmosis—a tick-borne bacterial infection—in patients with unexplained fever, as blacklegged tick prevalence rises in eastern Canada. In the US, the new world screwworm has been detected in 34 animals, mostly in Texas, and officials are expanding sterile fly production to slow its northward spread. Off Western Australia’s Ningaloo Reef, five whale entanglements in fishing gear were reported in five days, with one humpback dying and sharks swarming the carcass, prompting beach closures. The next milestone for the cyclosporiasis outbreak is identification of the specific food vehicle, which investigators in multiple states are pursuing through traceback interviews.