Egg-associated salmonellosis is an important public health problem. A bacterium, Salmonella enteritidis, can be inside perfectly normal-appearing eggs, and if the eggs are eaten raw or undercooked, the bacterium can cause illness. Consumers should be aware of the disease and learn how to minimize the chances of becoming ill.
A person infected with the Salmonella enteritidis bacterium usually has fever, abdominal cramps, and diarrhea beginning 12 to 72 hours after consuming a contaminated food or beverage. The illness usually lasts 4 to 7 days, and most persons recover without antibiotic treatment. However, the diarrhea can be severe, and the person may be ill enough to require hospitalization.
The elderly, infants, and those with impaired immune systems may have a more severe illness. In these patients, the infection may spread from the intestines to the blood stream, and then to other body sites and can cause death unless the person is treated promptly with antibiotics.
Who can be infected?
Healthy adults and children are at risk for egg-associated salmonellosis, but the elderly, infants, and persons with impaired immune systems are at increased risk for serious illness. In these persons, a relatively small number of Salmonella bacteria can cause severe illness. Most of the deaths caused by Salmonella enteritidis have occurred among the elderly in nursing homes. Egg-containing dishes prepared for any of these high-risk persons in hospitals, in nursing homes, in restaurants, or at home should be thoroughly cooked and served promptly.
What is the risk?
In affected parts of the United States, we estimate that one in 50 average consumers could be exposed to a contaminated egg each year. If that egg is thoroughly cooked, the Salmonella organisms will be destroyed and will not make the person sick. Many dishes made in restaurants or commercial or institutional kitchens, however, are made from pooled eggs. If 500 eggs are pooled, one batch in 20 will be contaminated and everyone who eats eggs from that batch is at risk. A healthy person's risk for infection by Salmonella enteritidis is low, even in the northeastern United States, if individually prepared eggs are properly cooked, or foods are made from pasteurized eggs.
What you can do to reduce risk
Eggs, like meat, poultry, milk, and other foods, are safe when handled properly. Shell eggs are safest when stored in the refrigerator, individually and thoroughly cooked, and promptly consumed. The larger the number of Salmonella present in the egg, the more likely it is to cause illness. Keeping eggs adequately refrigerated prevents any Salmonella present in the eggs from growing to higher numbers, so eggs should be held refrigerated until they are needed. Cooking reduces the number of bacteria present in an egg; however, an egg with a runny yolk still poses a greater risk than a completely cooked egg. Undercooked egg whites and yolks have been associated with outbreaks of Salmonella enteritidis infections. Both should be consumed promptly and not be held in the temperature range of 40 to 140 for more than 2 hours.
Reducing the risk of Salmonella enteritidisinfection
- Keep eggs refrigerated.
- Discard cracked or dirty eggs.
- Wash hands and cooking utensils with soap and water after contact with raw eggs.
- Refrigerate unused or leftover egg-containing foods.
- Avoid eating raw eggs (as in homemade ice cream or eggnog). Commercially manufactured ice cream and eggnog are made with pasteurized eggs and have not been linked with Salmonella enteritidis infections.
- Avoid restaurant dishes made with raw or undercooked, unpasteurized eggs. Restaurants should use pasteurized eggs in any recipe (such as Hollandaise sauce or Caesar salad dressing) that calls for pooling of raw eggs.