Cyclospora Cases Top 18,000 as Hawaii Joins Map

Federal health officials have confirmed 18,445 domestically acquired cyclospora infections since May 1, a record national outbreak of the parasite that causes prolonged watery diarrhea, with Hawaii newly added to the CDC's map of affected states.

The figure, current through Aug. 31 and posted in a CDC update on Tuesday, is up 1,265 cases from the 17,180 reported a week earlier. The agency counts 990 hospitalizations — 68 of them added in the past week — and two deaths.

Confirmed cases now span 49 states and the District of Columbia. The season officially ended Aug. 31, but the numbers are still climbing.

Why Cases Keep Rising

The CDC and FDA have said repeatedly that the recalled lettuce is no longer in the food supply — its best-by dates have passed, and FDA officials say they are confident the affected product has been removed from the marketplace.

Cases keep appearing anyway for two reasons. First, reporting lags: the CDC says it can take about six weeks from symptom onset for a case to be diagnosed, investigated and entered into national surveillance, so this week's numbers largely describe old infections. At least 13,505 additional cases are still awaiting laboratory confirmation, the agency said.

Second, the lettuce is not the only source. The CDC is investigating multiple clusters beyond the Taylor Farms outbreak and has said it is unlikely one common cause explains all of them. So far, only the lettuce source has been identified.

The overall trend is still down. USA TODAY notes that earlier weeks regularly saw increases in the 2,000 to 3,000 range, well above this week's 1,265.

Hawaii In, Delaware Out

Hawaii is the newest state on the CDC map, in the lowest bracket of 1 to 49 confirmed cases. Hawaii health officials say the recalled lettuce was not distributed or sold in the state, and investigators are still working out whether the island cases connect to another multistate outbreak or a separate source entirely.

Delaware is now the only state with no federally confirmed cases — a bookkeeping artifact, its health department says.

"Delaware is not exempt from cyclospora activity this season. The state has identified 13 probable Cyclospora cases," Sean Dooley, chief of public affairs at the Delaware Department of Health and Social Services, told Newsweek. "CDC's national map shows zero confirmed cases for Delaware because confirmation requires whole-genome sequencing, which is not routinely performed here. Specimens from our three most recent cases have been sent to CDC for sequencing, and those results are still pending."

Michigan remains the hardest-hit state on the federal map, in the 4,000-to-6,999 bracket — far below its own state-reported total, another product of the confirmation lag. USA TODAY lists Michigan and Ohio as the two states hit hardest.