The Salmonella Blues

“One cannot think well, love well, sleep well, if one has not dined well.” Virginia Woolf

Did you know that summertime is the prime time for food poisoning? If you think about it logically, you would have surmised such already. After all, when we are trying to save and preserve foods, we usually cool them or freeze them. Yet summer brings opportunities for picnics in the park, reunions at the old open air lodge, and covered dish suppers on the lawn. It also allows a little extra opportunity for foods to warm as you rush from the grocery store to the Cleaners and Post Office on your way home, and leave the bags in your car while completing these brief, final tasks. All of these settings increase the likelihood that food will warm and breed a variety of toxins and unsavory germs. Rather than food for thought, we’ll consider food for ‘festering’ this week.

Quantification of the impact of foodborne illness in the United States is impressive. It’s estimated that approximately 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths occur each year due to food poisoning. For those of you who like big words and technical terms, especially when Latin is involved, these next few sentences are for you! Bacteria causing foodborne illness include: Escherichia coli 0157:H7, Campylobacter jejuni, Salmonella, Staphyloccus aureus, Listeria monocytogenes, Clostridium perfringens, Vibrio parahaemolyticus, Vibrio Vulnificus, and Shigella. Viruses such as Hepatitis A and Norwalk can also cause food poisoning. And, last, but certainly not least, parasites such as Giardia, Cyclospora, and Cryptosporidium are a mouthful to say and even bigger actors on your stomach! While you digest these thoughts, let’s consider the summer factors specifically.

Food poisoning REALLY DOES increase during the summer months. There are two reasons. The normal bacteria (germs) present in soil, air, water, and on our bodies grow faster in the warm summer months. Additionally, the added humidity of summer months aids growth of bacteria. . .since most of them prefer heat and need moisture to flourish. Along these lines, it’ll turn your stomach to learn that one bacterium can multiply to 2,000,000 within 7 hours if conditions are right! Secondly, the dramatic increase in outside cooking, camping trips, barbecues, etc. make thermostat-controlled cooking, refrigeration, and washing facilities less available and the ingestion of improperly cooked and/or contaminated food more likely. Since all of us would rather regurgitate these facts than our picnic lunch, let’s move to prevention.

There are three basic rules of food poisoning prevention: 1) Keep food clean 2) Cook food adequately 3) Keep hot food hot and cold food cold. If you follow these rules, you’ll likely prevent most foodborne illnesses. Let’s look a little more specifically at each of these rules in closing.

Since unwashed hands are a prime cause of germ transmission to food, whenever possible, wash yours with warm soapy water before handling food, after using the bathroom, and after your brief wrestling match with Fido while you’re waiting to turn the burgers on the open grill. If there’s not a source of clean water in the park, bring your own supply or pack those disposable washcloths or moist towelettes and paper towels for cleaning hands and surfaces. When you pack your cooler of food, wrap the raw meats securely, so the juices can’t come in contact with ready-to-eat foods. And, always wash plates, utensils, and cutting boards that have been in contact with raw meat and/or poultry before using them again for cooked foods. Cross-contamination in this manner is a very common cause of food poisoning in all settings.

Take a food thermometer with you for those picnics in the park. Hamburger and other ground meats should be cooked to an internal temperature of 160 degrees F, and ground poultry to 165 F. Other recommended internal temperatures are available in most cookbooks. Remember that meat and poultry cooked on grills often brown fast on the outside, so perceptions of thorough cooking can be misleading without a thermometer to check internal cooking. Additionally, meat and poultry should be cooked completely at the picnic site. Partial cooking ahead of time does not kill bacteria in the food; in fact, it can allow them to multiply to the point that even subsequent cooking to desired internal temperatures cannot destroy them.

Keep perishable foods such as luncheon meats, potato salads and pasta salads, and cooked meats in insulated coolers packed with several inches of ice, ice packs, or containers of frozen water. Try to keep your coolers in the shade or at least out of direct sunlight, and replenish ice as soon as it starts melting to preserve cold temperatures. Another suggestion is to pack beverages in one cooler and perishable foods in another. At most outings, the beverage cooler will probably be opened frequently, while the perishable foods can remain cold until time to serve or prepare them.

Finally, foods requiring refrigeration may not be safe to eat if left out for more than 2 hours. If the temperature is 90 degrees F or more (which it IS in Nashville right now), food should not be left out more than 1 hour. You can see why that wonderful room-temperature potato salad. . .full of eggs and mayonnaise can wreak such havoc on the digestive tracts of hungry picnickers!

So, if you have any doubts, throw it out. You’ll lose a little food, but better to toss it, than to toss your cookies later on! Attention to cleanliness, adequate cooking, and appropriate cooling can keep you from singing the Salmonella Blues this summer

Stephen L. Hines, M.D.
July 2001