Lovers of frozen chicken nuggets have been issued a warning -- don't assume they're precooked and only need to be warmed before serving.

Following up on their study published in the June issue of the Journal of Food Protection, the B.C. Centre for Disease Control is urging consumers of frozen, prepared chicken nuggets and strips to cook them properly before putting them on the plate.

According to the study, one-third of people surveyed mistakenly thought the frozen snacks only needed to be heated.

That's a misconception, researchers say, that may be contributing to the risk of bacterial infection and possibly salmonella poisoning.

A quarter of the diagnosed salmonella cases in the study occurred in children under five years old.

Salmonella bacteria cause an infection of the gastrointestinal tract that can last several days. Symptoms include abdominal pain, severe diarrhea, fever, nausea or vomiting.

Although most people get better on their own, its effects can be more severe for children or people with weakened immune systems.

Looks are deceiving

According to the B.C. Centre's Laura MacDougall, nuggets' crispy-looking coating is what seems to be fooling consumers.

"They don't give us visual cues that we would associate with raw chicken," MacDougall told CTV News. "They go through a par-frying process, or most of the nuggets do, so that they look golden brown on the outside. When you cut them open, they also don't look obviously raw on the inside, they don't bleed."

She also said most packaging doesn't explicitly say the products are raw.

When health authorities in Quebec studied several types of frozen nuggets and chicken strips last year, they found traces of salmonella in approximately one-third of the samples.

Although that's not unusual for raw chicken, the fact consumers are confused about the proper cooking instructions increases the risk.

The published report also raises a concern about the use of microwaves. Microwave cooking of chicken nuggets and strips is not recommended because it may not heat the product evenly. But the report found that almost 30 per cent of those surveyed reported using the microwave sometimes or always when cooking these products.

Researchers also stress the importance of washing hands after handling any type of raw chicken product. In contrast to hand-washing habits after handling obviously raw chicken, the study found people washed their hands less often after handling the frozen products.

In response, the government is drafting a new law to make detailed labelling of the kids' favourites mandatory.