LOS ANGELES, July 14 (Xinhua) -- U.S. cyclosporiasis reports are rising rapidly, with state and local systems recording far more cases than federal figures and an analysis backlog, the U.S. Centers for Disease Control and Prevention (CDC) said Tuesday.
The CDC said it had received 1,645 laboratory-confirmed cases of cyclosporiasis across 34 states since May 1, 2026, with 141 hospitalizations and no deaths, in addition to more than 5,100 reports requiring analysis before they could be classified as domestically acquired.
The CDC said the total was substantially higher than the 249 cases reported nationally from May 1 through July 16, 2025, while assuming a reporting lag of about six weeks between illness onset and national case reporting.
Some state and local intake figures already exceed the narrower federal count.
The Michigan Department of Health and Human Services reported 3,309 cases on Tuesday, about twice the national confirmed total and surging from a typical yearly record of around 50 cases.
In Ohio, the Toledo-Lucas County Health Department reported 1,119 preliminary positive laboratory results across the state's northwest as of Tuesday.
The New York State Department of Health and New York City Health Department reported a combined 510 cases as of July 8, according to a joint advisory.
The figures are not directly comparable because state systems may include probable, travel-associated or still-unclassified reports, while the CDC counts only laboratory-confirmed cases classified as acquired in the United States.
The CDC expected the national total to keep rising as pending reports were processed, alongside continuing investigations into the sources of the outbreaks.
Cyclosporiasis is an intestinal illness caused by a microscopic parasite contracted by consuming contaminated food or water, which is unlikely to spread directly between people, according to the CDC.
The CDC said more than 400 cases in Michigan, Ohio, West Virginia and Kentucky appeared epidemiologically linked to a single multistate outbreak, but no specific food had been confirmed as the source. Investigators were interviewing patients and conducting traceback work, it added.
Michigan investigators said early interview results indicated lettuce or salad greens were possible sources in the state's outbreak, advising people in impacted counties to buy whole heads of lettuce rather than pre-washed bagged lettuce or pre-mixed salad kits, to discard the outer two or three layers of leaves, and to heat food to at least 70 degrees Celsius. ■