More than 3,000 sick in Michigan and Ohio as Cyclospora outbreak sparks lettuce warning

Health officials in Michigan are investigating whether lettuce or salad greens are linked to a growing Cyclospora outbreak that has sickened more than 3,000 people across Michigan and Ohio.

Michigan has reported 2,640 cases, including 44 hospitalisations, while Ohio has recorded 361 cases since 1 June. More than 46 people have been hospitalised across the two states.

State officials said lettuce has emerged as a common food reported by patients, but no specific type, grower or supplier has been identified.

“Early information has shown lettuce as a common product that regularly comes up during the investigation,” Michigan chief medical executive Dr Natasha Bagdasarian said in a statement on Monday.

The US Centers for Disease Control and Prevention (CDC) said 31 states have reported Cyclospora cases, although it is still investigating whether they are connected to the same outbreak.

Cyclospora is a parasite that usually spreads through contaminated fresh produce or water. Symptoms include prolonged diarrhoea, stomach cramps and bloating, and some patients may require hospital treatment for dehydration.

Officials also say Cyclospora is more difficult to track than bacteria such as E. coli or salmonella, making outbreak investigations more challenging.