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Norovirus is the leading cause of food-borne outbreaks in the US, with fresh produce (especially leafy vegetables and fruits) among the most common culprits.

While you can be infected with norovirus through direct contact with someone who’s infected, this virus is often spread through the fecal-oral route, when you consume food or water that’s contaminated.

According to the US Centers for Disease Control and Prevention (CDC), sick food handlers are the main source of food-borne norovirus outbreaks and caused about half of such cases from 2001 to 2008.

This makes sense, since norovirus outbreaks are commonly associated with contaminated foods from restaurants and long-term care facilities. It turns out there may be an additional culprit, however, an insidious one that to date has received very little attention.

Dirty Water Used to Dilute Pesticides May Spread Norovirus

Contaminated water has long been recognized as a potential introduction source of norovirus to fresh produce, but typically this has centered on water used to irrigate crops.

Researchers from the Netherlands decided to look into the water used to reconstitute pesticides to determine if that could be a relevant source of infectious norovirus, and their results revealed a strong possibility that it could.

They tested four fungicides and four insecticides commonly used on lettuce and raspberries (two foods associated with norovirus outbreaks), diluted with water that had been spiked with norovirus.