Salmonella Enteritidis and Shell Eggs:

Salmonella contamination of eggs is an important public health problem in the United States. Salmonella contamination of eggs by serotype enteritidis–the strain involved in the massive Salmonella outbreak and recall associated with eggs from Wright County Egg–more specifically, was formerly a problem that occurred most frequently in the northeastern United States, but now illness caused by S. enteritidis is increasing in other parts of the country as well. 

Most types of Salmonella live in the intestinal tracts of animals and birds and are transmitted to humans by contaminated foods of animal origin. Stringent procedures for cleaning and inspecting eggs were implemented in the 1970s and have made salmonellosis caused by external fecal contamination of egg shells extremely rare. However, unlike eggborne salmonellosis of past decades, the current epidemic is due to intact and disinfected grade A eggs. The reason for this is that Salmonella enteritidis silently infects the ovaries of healthy appearing hens and contaminates the eggs before the shells are formed.

Although most infected hens have been found in the northeastern United States, the infection also occurs in hens in other areas of the country. In the Northeast, approximately one in 10,000 eggs may be internally contaminated. In other parts of the United States, contaminated eggs appear less common. Only a small number of hens seem to be infected at any given time, and an infected hen can lay many normal eggs while only occasionally laying an egg contaminated with the Salmonella bacterium.

Reducing the Risk of Salmonella Enteritidis Infection:

*  Keep eggs refrigerated.

*  Discard cracked or dirty eggs.

*  Wash hands and cooking utensils with soap and water after contact with raw eggs.

*  Eat eggs promptly after cooking. Do not keep eggs warm for more than 2hours.

*  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.