Huge Salmonella Outbreak Traced to Recalled Eggs: What You Should Know
Daniel J. DeNoon
WebMD Health News
Latest Infectious Disease News
Reviewed By Laura J. Martin, MD
Aug. 20, 2010 -- It's the biggest egg recall in recent memory. Eggs contaminated with salmonella have sickened thousands of Americans.
What do you need to know? Here is WebMD's FAQ on the ongoing egg recall and salmonella outbreak.
Why are the eggs being recalled?
As early as April, states began noticing an unusual number of cases of salmonella food poisoning due to Salmonella enteritidis or SE. In recent years, SE has become the most common cause of salmonella infections in the U.S. It's predominantly found in eggs.
Aided by the CDC, health departments in 10 states identified 25 SE outbreaks among people who ate at the same restaurant or event where food was served. Fifteen of these restaurants served eggs traced to a single firm in Iowa, Wright County Egg.
However, on Aug. 20 a second Iowa firm issued a recall of eggs due to suspected salmonella contamination.
How many people are sick?
As of mid-July, the CDC had 2,000 confirmed reports of SE illness -- 1,300 more cases than usual for this time of year.
Most cases of salmonella do not get reported. The CDC usually calculates that for every reported case, 38 people are sickened. That would mean that the outbreak may already have sickened some 76,000 Americans. And the CDC expects to receive more reports before the outbreak is over.
The FDA says it's the biggest outbreak in recent history. But perspective is needed. The FDA calculates that there are 141,990 egg-related SE illnesses each year in the U.S.
The FDA calculates that about 91% of salmonella cases are mild -- that is, don't require a doctor visit and get better in one to three days. About 8% of cases are moderate, requiring a doctor visit and two to 12 days for recovery. And just over 1% of cases are severe, requiring hospitalization and 11 to 21 days for recovery. A small number of patients die.
Moreover, 3.7% of patients have lingering arthritis even after their other salmonella symptoms resolve. For 2.4% of patients, this arthritis lasts for a year or longer.
Do I have contaminated eggs in my refrigerator?
Maybe. Some 380 million eggs, sold under at least 16 different brand names, have been recalled. The egg industry has posted an updated list of recalled egg brands and their identifying package details.
Two previous recalls were issued by Wright County Egg of Galt, Iowa, on Aug. 13 and Aug. 18. On Aug. 20, Hillandale farms of Iowa issued a third recall.
Hundreds of millions of eggs would make a lot of omelets. But the recalled eggs actually represent less than 1% of the U.S. egg supply. The U.S. produces around 67 billion eggs each year. About 47 billion are sold in the shell as table eggs; the rest are processed into products such as pasta, cake mix, ice cream, mayonnaise, and baked goods.
The huge size of the farm linked to the salmonella outbreak isn't unusual. More than 4,000 U.S. farms have 3,000 or more laying hens that produce about 90 eggs per 100 hens per day. About 17% of farms in the states that produce the most eggs (California in the west; Ohio, Indiana, Iowa, and Pennsylvania in the east) have more than 30,000 laying hens.
On the other hand, the FDA estimates that each year, U.S. farms distribute 2.3 million eggs filled with salmonella. The CDC estimates that one in 50 consumers is exposed to a contaminated egg each year.
Unfortunately, an egg contaminated with salmonella appears normal.
How do eggs get contaminated with salmonella?
It once was thought that salmonella on the surface of eggs penetrated the shell and infected the egg contents. That's possible. But it's now becoming clear that a hen infected with salmonella can carry the bacteria in its ovaries and oviducts. The eggs become infected with salmonella as they are forming.
Interestingly, the site of contamination is usually -- but not always -- the egg white.
Not every hen at the same farm carries salmonella, and not every egg laid by an infected hen carries the bug.
Hens get salmonella mainly from germs carried by flies and from eating the excrement of rodents that get into their feed. New FDA regulations -- which ironically went into effect on July 9, well after the current salmonella outbreak began -- are expected to cut the number of salmonella-carrying eggs by 60%.
What are the symptoms of Salmonella Enteritidis infection?
Infants, the elderly, and people with compromised immune systems may get very severe diarrhea and require hospitalization.
How is Salmonella Enteritidis treated?
Fortunately, most cases of SE get better without any treatment other than drinking fluids to replace those lost to diarrhea.
More severe diarrhea will require fluid and electrolyte replacement.
Antibiotics usually are not used except for very severe disease, or for high-risk patients. In fact, antibiotics can actually prolong salmonella duration.
What can I do to avoid salmonella illness from eggs?
Here's the CDC's advice:
- Don't eat recalled eggs or products containing recalled eggs. Recalled eggs might still be in grocery stores, restaurants, and homes. Consumers who have recalled eggs should discard them or return them to their retailer for a refund.
- People who think they might have become ill from eating recalled eggs should consult their health care providers.
- Keep eggs refrigerated at least to 45 degrees F at all times.
- Discard cracked or dirty eggs.
- Wash hands, cooking utensils, and food preparation surfaces with soap and water after contact with raw eggs.
- Eggs should be cooked until both the white and the yolk are firm and eaten promptly after cooking.
- Do not keep eggs warm or at room temperature for more than two hours.
- Refrigerate unused or leftover egg-containing foods promptly.
- Avoid eating raw eggs.
- 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 raw eggs.
- Consumption of raw or undercooked eggs should be avoided, especially by young children, elderly people, and people with weakened immune systems or debilitating illness.
News release, FDA.
News release, CDC.
CDC/FDA news teleconference, Aug. 19, 2010.
Final Rule, Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation. Federal Register, July 9, 2009.
eMedicine web site.
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