Health officials in Canada say many foods at holiday parties can carry bacteria that cause illness so food safety precautions are a must. Health Canada officials also warn raw or undercooked fish (oysters and sushi) might contain bacteria, parasites or viruses. Keep seafood refrigerated and serve it on ice. However, people who are more vulnerable to the risks of foodborne illness, such as older adults, pregnant women, young children and people with weakened immune systems, should avoid eating raw or undercooked fish and seafood. The health officials also said: -- Uncooked cookie dough, batters or frostings made with raw eggs could contain Salmonella bacteria. Always make sure baked goods are cooked thoroughly and never lick the spoon or eat raw cookie dough. -- Store-bought eggnog is pasteurized to remove any bacteria, but if making eggnog using raw eggs, be sure to heat the egg and milk mixture to at least 71 degrees C or 160 degrees F. Immediately after heating, refrigerate the eggnog in small, shallow containers to allow it to cool quickly. Or, use pasteurized egg and milk ingredients, which are available at many grocery stores. -- If making punch or serving cider, check the product label to make sure the juice or cider has been pasteurized. Unpasteurized juice may contain bacteria like E.coli or Salmonella.