US Cyclospora Outbreak Nears 7,000 Cases as Officials Eye Salad Greens

Verified key facts

• The CDC confirmed 1,645 laboratory-verified cases across 34 states since 1 May, with over 5,100 more under review, approaching 7,000 total.
• More than 400 cases in Michigan, Ohio, West Virginia and Kentucky are epidemiologically linked in a single multistate outbreak.
• Michigan reported more than 3,300 cases as of 14 July, far exceeding all other states.
• As of mid-July there had been 141 hospitalisations nationwide and no reported deaths.

An outbreak spreading across dozens of states

A large cyclosporiasis outbreak is unfolding across the United States. According to CNN, cases have risen above 3,000 in Michigan alone. Nationally the total is far higher and still climbing.

The Centers for Disease Control and Prevention has confirmed 1,645 laboratory-verified domestic cases in 34 states since 1 May. The agency says it is aware of more than 5,100 additional cases under review. Combined, the figure approaches 7,000.

That scale dwarfs recent years. The CDC noted just 249 cases reported nationally at the same point last year. This season's tally represents a steep and unusual rise.

The gap between confirmed and pending cases reflects laboratory workload. Testing for the parasite takes time and specialist methods. As results are processed, the confirmed count is expected to move closer to the fuller estimate.

What cyclosporiasis is

Cyclosporiasis is a gastrointestinal illness caused by the parasite Cyclospora cayetanensis. It is spread when people consume food or water contaminated with the parasite. It is not passed directly from person to person.

The illness typically causes watery diarrhoea that can last for weeks if untreated. Other symptoms can include fatigue, cramping and loss of appetite. NPR reported that the affliction can be prolonged and draining for those affected.

As of mid-July there had been 141 hospitalisations nationwide, according to reporting on CDC figures. No deaths had been reported. Anyone with persistent symptoms should seek advice from a qualified healthcare professional.

The Michigan-centred cluster

The CDC has identified a specific multistate cluster within the broader picture. It says more than 400 people in Michigan, Ohio, West Virginia and Kentucky are epidemiologically linked. Illness onset dates began on or after 22 June 2026.

Michigan is by far the most affected state. The Michigan Department of Health and Human Services reported more than 3,300 cases as of 14 July. That total exceeds every other state in the country.

A CDC official pointed to two separate peaks in illness-onset dates. One clustered around 25 June and another around 7 July. That pattern suggests two separate batches of a contaminated ingredient may be involved.

The hunt for a source

Investigators have not confirmed a specific food source. Federal and state officials are examining lettuce and salad greens. The work remains ongoing.

Michigan's chief medical executive, Dr Natasha Bagdasarian, said lettuce regularly came up during the investigation. She described it as a common product appearing in patient interviews. She stressed the conclusion was preliminary and unconfirmed.

No specific type, grower or supplier has been identified. Officials say the suspicion has not been confirmed through environmental or supply-chain testing. That caution matters, because premature blame can misdirect a response.

• 1,645 confirmed cases plus over 5,100 under review across 34 states
• More than 400 cases linked in a Michigan-Ohio-West Virginia-Kentucky cluster
• Two illness peaks around 25 June and 7 July suggesting separate batches
• Lettuce and salad greens under examination but not confirmed

Cross-border attention

The outbreak has drawn notice beyond US borders. CTV News reported that Canada's food inspection agency said it was not banning produce imports over the outbreak. The agency sought to reassure consumers while monitoring the situation.

Cyclospora outbreaks have historically been linked to fresh produce. Salad greens, herbs and berries have featured in past US clusters. That history is part of why investigators are focused on the produce supply chain now.

The parasite is not visible to the eye and can survive on produce. Because it is not spread person to person, tracing rests on identifying a shared food. That makes patient interviews and supply-chain data central to the investigation.

The Globe and Mail reported that Canadian health officials were advising the public about the illness as US cases climbed. Cross-border produce supply chains mean outbreaks rarely respect national boundaries. Monitoring has extended beyond the United States.

General guidance and next steps

Public health agencies typically advise general food-safety hygiene during such outbreaks. Washing produce and following official guidance are standard prevention messages. These are broad measures, not a guaranteed shield against a parasite this small.

The investigation is expected to continue as laboratories process the large backlog of cases under review. The final total may shift as those results come in. Health officials will look for the common ingredient that connects the clusters.

For now the picture is one of an unusually large season. People experiencing prolonged diarrhoea are encouraged to contact a healthcare provider, who can arrange testing. Diagnosis matters because cyclosporiasis requires specific medical management rather than routine care.

Sources

• CNN - Michigan says diarrhea outbreak may be linked to lettuce as cases rise above 3,000 (13 July 2026)
• NPR - What to know about cyclosporiasis, the intestinal illness hitting the U.S. (12 July 2026)
• CDC - Cyclospora Outbreak with Unknown Source, 2026