From the WebMD Archives

Dec. 20, 2018 -- Even though you plan to peel it, wash that avocado first. Almost 18% of avocado skins tested positive for listeria in samples taken by the FDA from 2014 to 2016. Less than 1% of pulp samples -- that’s the part you eat -- tested positive for the harmful bacteria. The agency published the results of the testing earlier this month.

Eating food contaminated with listeria can cause listeriosis, an illness that can send you to the hospital and cause death. People at greatest risk are pregnant women, the elderly, and people with weak immune systems.

The FDA recommends washing all produce under running water and scrubbing firm produce with a clean produce brush before cutting or peeling it. When you cut into unwashed produce, you can transfer contaminants from the knife to the fruit.

Listeria can also spread from contaminated foods to refrigerators and other kitchen surfaces. The FDA recommends cleaning up spills and leaks inside refrigerators immediately and washing the inside with warm soapy water regularly.

When foods test positive for listeria or other harmful bacteria, the FDA alerts the manufacturer and issues recalls as needed.