Killing Kitchen Germs

Q:  You recently wrote about how to handle poultry to avoid food poisoning. You mentioned the importance of cleaning the cutting boards and knives and washing your hands, but you did not mention whether it was necessary to rinse the raw chicken. My husband does not wash a chicken before he cooks it and tells me the germs get killed during cooking.

He also keeps the same kitchen sponge for months, even though he uses it to clean up after preparing chicken. I am a diabetic and do not want to get sick, but I cannot get him to change.

Am I being phobic?

A:  Rinsing poultry before cooking is a good way to limit the number of bacteria that are almost certainly living on the raw surface. However, as long as the chicken is fully cooked, any remaining bacteria will die. Reusing a dirty (and likely salmonella-laden) sponge is not a good idea. Some groups recommend using paper towels to clean up after working with raw poultry.

A reader who is a microbiologist tells me that many pathogenic microbes residing in a sponge cannot be destroyed by soap and water, especially those as hardy as salmonella. I also want to thank another reader for alerting me to a story in the January/February 2003 issue of Cook's Illustrated, which studied this subject.

"The article details how Cook's took dirty kitchen sponges with bacterial counts of 41 million to 59 million colony forming units (CFUs) per sponge and subjected them to a variety of cleansing methods. Freezing the sponges for 48 hours did nothing to disinfect them. Soaking them in soap and hot water for two minutes left 1.4 million CFUs. Putting them through the dishwasher left 410,000 CFUs. Soaking them in a bleach solution left 2,000 CFUs. Both boiling the sponges for three minutes and microwaving them for three minutes worked the best, in each case leaving the sponges with 1,000 CFUs."

So two minutes of soap and hot water removed about 97% of the bacteria while microwaving or throwing the sponges in the dishwasher got much closer to total disinfection. The reader offered her strategy: "I toss my sponge in the dishwasher to get rid of the surface grime, and then throw it in the microwave to finish the little buggers off. While my sponges don't seem to last quite as long, the 79 cents for another sponge seems a small price to pay for food safety." Good point.

Finally, you are right to be concerned for your health. Anyone who has a greater-than-average susceptibility to infection should be extra careful. The safest option is to disinfect or replace any sponge used to clean surfaces, cutting boards or knives that have come in contact with raw poultry, meat or eggs.

Julie L. Mitchell, MD, MS, is an Assistant Professor of Medicine at the Medical College of Wisconsin. She practices internal medicine at the Froedtert & Medical College General Internal Medicine Clinic - East. Her column also appears in the Milwaukee Journal-Sentinel.

For more information on this topic, see the HealthLink article Good Food – and Why It Can Make Us Sick.