A parasite that causes explosive diarrhea and can linger for months is sweeping through the American food supply, and the federal agency tasked with keeping your food safe still can't tell you where it's coming from. Meanwhile, the big chains are ghosting the public and small businesses are left to protect their customers on their own.

The CDC counts over 840 confirmed cyclosporiasis cases as of July 9, but state health departments report far higher numbers. Michigan alone has identified over 1,500 cases with 44 hospitalizations — a state that typically sees about 50 cases a year. Thousands more are suspected across the country, with outbreaks concentrated in Michigan, Illinois, Virginia, Ohio, and New York.

Cyclospora spreads when people eat fresh produce contaminated with fecal matter — usually from tainted irrigation water. The infection isn't typically life-threatening and can be treated with antibiotics, but without treatment, symptoms including watery and sometimes explosive diarrhea, cramping, fatigue, nausea, and vomiting can drag on for more than a month. Food safety lawyer Bill Marler put it plainly: "It is not pleasant, and it can last for months."

So what is the FDA — the agency with a $6.7 billion budget responsible for food safety — doing about it? Thus far, investigators have not identified a specific produce supplier or even a specific type of produce as the source. The CDC's acting parasitic diseases branch chief, Dianna Blau, told the Associated Press it's "not immediately clear how unusual this year will be." Not exactly a confidence builder.

The Independent framed the story around Taco Bell, which posted signs at several Metro Detroit locations reading: "We are currently unable to sell Lettuce, Cilantro, Onion, Pico de Gallo and Guacamole due to a nationwide recall." USA Today, by contrast, led with general consumer caution and buried the more uncomfortable fact that major national chains have gone completely silent.

USA Today reached out to the National Restaurant Association and several major fast-food chains — McDonald's, Chick-fil-A, Jersey Mike's, Burger King, Subway, and Wendy's. None returned requests for comment. Taco Bell's parent company YUM! Brands also did not respond. Chipotle — a chain that knows a thing or two about foodborne illness scandals — issued a statement saying it's "monitoring the situation" and doesn't believe its ingredients are associated with the outbreak.

Meanwhile, it's the little guys doing the obvious thing. Dipisa's Pizza in Stevensville, Michigan, posted on Facebook that it's pulling lettuce, tomatoes, and onions from the menu. "Rather than take any unnecessary risks, we've decided it's best to pause serving these fresh produce items until more information is available and the situation is resolved," the pizzeria wrote.

One restaurant acts. A dozen national chains duck and cover. And the regulators with billions in funding can't trace a parasite that sickens thousands. The outbreak has not been declared a national health emergency.

Americans are eating feces-contaminated produce and the best the system can offer is "be paranoid" and wash your hands. The question isn't just what's in your salad — it's what exactly the FDA is doing with all that money before it ends up on your plate.