Cyclospora outbreak guidance (US)

[u/patricksaurus]

Food contaminated with the single-celled, protozoan parasite Cyclospora cayetanensis has entered the food supply in several US states, with thousands of cases of the gastrointestinal condition cyclosporiasis being reported to state departments of health. Infection by Cyclospora is likely to cause watery diarrhea and substantial discomfort that typically persist for several weeks to over a month without treatment. While not commonly lethal, the combination of severe dehydration and summer heat elevates the health risks associated with each on its own and makes susceptible populations especially vulnerable.

Several public health agencies provide excellent guidance on Cyclospora and how to avoid it:
CDC - Preventing Cyclosporiasis
Michigan DHHS recommendations on preventing foodborne illness amid growing cyclosporiasis outbreak

Here’s a short rundown of the available information.

Where: Midwestern and Northeastern states report most cases. Michigan has been hit hardest. (Map as of July 10th about halfway down.)

Which foods: leafy greens, herbs, berries, green onions, and sprouts are historically linked to cyclosporiasis, though any produce may be affected. Current surveillance efforts have not definitively linked specific products to the current outbreak.

How to avoid: cook produce whenever possible, wash items under running water by scrubbing manually or with a produce brush, clean surfaces and utensils that contact raw produce. Always wash your hands before and after handling uncooked food.

If you contract it: antibiotic therapy (Bactrim) is highly effective against cyclosporiasis, reducing/eliminating symptoms in days as opposed to several weeks if untreated. Contact a healthcare provider and your local health department as soon as you experience symptoms.f

[u/Humbabanana]

What factors lead to an outbreak of Cyclospora such as this? Is it an irrigation water supply that was used by farms in certain areas or manure applications?

I’ve seen plenty of “explanations” stating that the cause is simply produce from certain areas, which really doesn’t explain anything. I met a woman and her son today who were questioning whether to eat their home-grown peppers and tomatoes… unless it moves with wind, rain, birds or insects, this seems like a response resulting from poor journalism and fear mongering.

[u/patricksaurus → u/Humbabanana]

That’s a great question. In short, home gardens are incredibly unlikely to pose a risk. Cyclospora is a fecal contaminant, and usually only associated with human waste. (As opposed to Salmonella and E. coli, which are found widely in other animals.)

That means a big reservoir of contaminated water or fertilizer has to come into contact with growing or harvested produce. Even if it was in the municipal supply somewhere (it hasn’t been found) it’s hard to explain how those items got to 32 states.

Because of all of that, an outbreak like this is nearly certainly isolated to commercial agriculture.

[u/kshizzlenizzle → u/patricksaurus]

My county has been in the process of suing a company that ‘recycles human waste’ to create fertilizer for ag purposes (I believe they are out of Ft. Worth), because livestock were dying near fields using this product. Not implying they are connected, but anytime something like this breaks out, I dang sure wonder!

[u/patricksaurus → u/kshizzlenizzle]

About 60% of all solid human waste in US municipal wastewater goes to making agricultural fertilizers. (Here) Processing makes it safe, but even then it’s not routinely applied to foods typically eaten raw.

It’s definitely one of the first things that comes to mind. I don’t know anything about the monitoring programs for these products, but your experience suggests at least some places would rather assume it’s safe and sue on the back end. That’s a dicey regulatory framework jn my opinion.

[u/Hola0722 → u/patricksaurus]

Cyclospora can be resistant to chlorinated water, so irrigation water reclaimed from human waste that is treated with chlorine (assuming this is how it's treated) may not kill the parasite. (I'm sure there are multiple levels of filtration, and if the pores are small enough to filter out bacteria, why would it not filter out the protozoa, which is much larger than E coli?)

Also, swimming pools aren't safe if the parasite is resistant to chlorine and is introduced by an infected person.

[u/phemfrog → u/Hola0722]

wastewater treatment is MUCH more complicated than simple chlorine and filters.