The Middlesex-London Health Unit is calling on residents to thoroughly wash and cook fiddleheads before eating the seasonal vegetables. The reminder comes after five people in the Toronto area became ill after eating fiddleheads. Fiddleheads are the curled, edible shoots of the ostrich fern that are often eaten at this time of year.

While they are uncommon, cases of illness associated with eating raw or undercooked fiddleheads are reported periodically across Canada. At this time the cause of the illnesses associated with fiddleheads has not been identified, but it is believed to be an unidentified natural toxin in the plant.

Symptoms of illness appear within 30 minutes to 12 hours of eating raw or undercooked fiddleheads and typically last for less than 24 hours, but may last as long as three days. Symptoms may include diarrhea, nausea, vomiting, abdominal cramps and headaches.

Fiddlehead food safety tips include:

• Never eat raw fiddleheads.
• Remove as much of the brown, papery husk as possible.
• Wash the fiddleheads well using fresh, cold water.
• Cook fiddleheads by boiling them for 15 minutes or by steaming them for 10 to 12 minutes.
• Discard water used for boiling or steaming fiddleheads, as it may contain the toxin.

For more information about how to safely enjoy fiddleheads, visit Health Canada's website.

Anyone who believes they may have become ill as a result of eating fiddleheads should contact the Middlesex London Health Unit at 519-663-5317 ext. 2300, or visit their health care provider