Michigan Cyclosporiasis Cases Rise 3% Weekly as Outbreak Shows Signs of Easing

Michigan's health department reported 14,277 cases linked to the ongoing cyclosporiasis outbreak on Thursday, an increase of 368 cases, or roughly 3%, from the previous week. The slower pace of growth suggests the outbreak may be beginning to ease, officials said.

The state, which has been the hardest hit in the multistate outbreak, previously attributed the sharp rise in numbers to a backlog in processing reports. New infections have been slowing, according to the department.

Jeffrey Griffiths, a professor of public health and medicine at Tufts University, said the data indicates the outbreak has peaked. "The peak of 3,585 (reported in the week through July 12) is almost 19 times higher than the last reported week, so that is a big drop," he noted.

The outbreak, linked to iceberg lettuce, is among the largest foodborne illness events in recent U.S. history. Symptoms include diarrhea, nausea, and other gastrointestinal distress. The illness has prompted many consumers nationwide to avoid fresh produce and restaurant dining.

Griffiths suggested the decline in Michigan could be because the contaminated food has been consumed, removed from markets, or aged out of circulation. The U.S. Food and Drug Administration has assured the public that it is safe to resume eating fresh produce, stating it is confident all affected iceberg lettuce has been cleared from the market.

Tracing the disease is difficult due to its two-week incubation period and the fact that it cannot be identified using advanced genetic testing methods, unlike many other foodborne pathogens.

Within Michigan, Wayne County reported the most cases at 2,029, followed by Oakland County with 1,499. Adults aged 30 to 39 accounted for the largest share of infections, with 2,879 cases.

The U.S. Centers for Disease Control and Prevention has recorded 15,716 laboratory-confirmed cyclosporiasis cases across 47 states as of August 18. State figures may be higher than CDC counts because they can include cases that do not meet the agency's formal reporting criteria.