Michigan health officials just reported the first two deaths from the state’s ongoing outbreak of the explosive diarrhea-causing foodborne illness cyclosporiasis, marking the first fatalities reported in the U.S. since the surge of cases began earlier this year.
The deceased patients had “significant underlying health conditions that may have been impacted by cyclosporiasis and dehydration,” according to the state’s Department of Health and Human Services. Their names or ages were not released.
“No additional information will be provided on these two cases,” it said Monday.
Michigan is the state with the largest number of cases nationwide, and officials reported there were 11,234 sickened and nearly 200 people hospitalized so far. More than 17,000 cases are being investigated in the U.S.
Cases in the Great Lakes state and eight others – including West Virginia, Oklahoma, Pennsylvania, Ohio, Kentucky, Kansas, Indiana and Illinois – have been tied to contaminated lettuce.
That outbreak is the largest in the nation and led to salad-maker Taylor Farms’ recall of iceberg lettuce sourced from Central Mexico. The lettuce had been served at several locations of the fast-food chain Taco Bell and the recall also included lettuce that was sold at retail stores.
There are now several outbreaks reported nationwide, but questions still swirl surrounding sources of exposure. There have also been reports of outbreaks in the U.K.
Some cases in North Carolina have been linked to parsley and cilantro, state health officials said.
In a typical year, the U.S. sees just a few thousand cases, experts told CNN.
While the Centers for Disease Control and Prevention has received 6,707 lab-confirmed cases of cyclosporiasis since May 1 and is aware of more than 11.500 additional cases that are not lab-confirmed, it only shows Michigan with 1,000-4,000 cases on its surveillance webpage.
The agency says there is a six-week lag between illness onset and case reporting, and it anticipates that case counts will continue to rise.
Part of that is because of the nature of cyclosporiasis. Infections are caused when people are exposed to the parasite cyclospora, often through produce.
But it can take weeks for symptoms of infection to appear, including vomiting, nausea and dehydration.
By this time, people may have forgotten what they had consumed and tainted products may already be out of grocery stores.
It’s also hard to trace cyclospora. The microscopic parasite – which is only spread by humans – cannot be traced using advanced testing methods that help scientists with bacteria and pathogens.
“FDA relies on whole genome sequencing to effectively fingerprint a pathogen to try to isolate a particular pathogen to a particular outbreak to a particular grower. You don’t have that in this case,” former FDA Commissioner Scott Gottlieb told Reuters.