Multistate Outbreak of Human Salmonella Enteritidis Infections Associated with Shell Eggs
Posted August 16, 2010
This outbreak appears to be over. However, Salmonella is an important cause of human illness in the United States. More information about Salmonella, and steps people can take to reduce their risk of infection, can be found on the CDC Salmonella Web Page.
CDC is collaborating with public health officials in many states, the U.S. Food and Drug Administration (FDA), and the U.S. Department of Agriculture’s Food Safety and Inspection Service to investigate a nationwide increase of Salmonella Enteritidis (SE) infections with an indistinguishable pulsed-field gel electrophoresis (PFGE) pattern JEGX01.0004. This is the most common PFGE pattern for SE in the PulseNet database. Investigators are using DNA analysis of Salmonella bacteria obtained through diagnostic testing to identify cases of illness that may be part of this outbreak.
Investigation of the Outbreak
In May 2010, CDC identified a nationwide increase in the number of Salmonella Enteritidis isolates with PFGE pattern JEGX01.0004 uploaded to PulseNet, the national subtyping network made up of state and local public health laboratories and federal food regulatory laboratories that performs molecular surveillance of foodborne infections. The increase represents approximately a four-fold increase over the expected number of reported isolates of this particular PFGE pattern. Approximately 200 isolates were uploaded to PulseNet on a weekly basis during late June and early July compared to an expected ~50 uploads a week on average during this same period in the previous 5 years. Many states have reported increases of this pattern since May.
Epidemiologic investigations conducted by public health officials in California, Colorado, and Minnesota have revealed several restaurants or events where more than one ill person with the outbreak strain has eaten. Preliminary data suggests that shell eggs are a likely source of infections in many of these restaurants or events. State partners, FDA, and CDC, conducted a traceback and found many of these restaurants or events received shell eggs from a single firm, Wright County Egg, in Galt, Iowa. FDA is currently conducting an extensive investigation at the firm in Iowa. The investigation includes CDC participation and involves sampling, records review and looking for potential sources of contamination, such as feed. The investigation continues and updates will be made available.
On August 13, 2010, Wright County Egg of Galt, Iowa conducted a nationwide voluntary recall of shell eggs.
Clinical Features/Signs and Symptoms
A person infected with Salmonella Enteritidis 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 hospitalization may be required. The elderly, infants, and those with impaired immune systems may have a more serious 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. For more information, visit CDC’s Salmonella Enteritidis website.
Advice to Consumers
- Don’t eat recalled eggs. Recalled eggs might still be in grocery stores, restaurants, and consumers' homes. Consumers who have recalled eggs should discard them or return them to their retailer for a refund.
- Individuals who think they might have become ill from eating recalled eggs should consult their health care providers.
- Keep eggs refrigerated at ≤ 45° F (≤7° C) at all times.
- Discard cracked or dirty eggs.
- Wash hands and all food contact surface areas (counter tops, utensils, and cutting boards) with soap and water after contact with raw eggs. Then, disinfect the food contact surfaces using a sanitizing agent, such as bleach, following label instructions.
- 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 2 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 persons, and persons with weakened immune systems or debilitating illness.
Advice to Egg Producers
- Flock-based SE-control programs that include routine microbiologic testing are mandatory for producers with more than 50,000 hens, as of July 9, 2010, under FDA's egg safety rule.
Advice to Retail and Food Service Establishments and Institutional Settings
- In retail and food service establishments, pasteurized egg products or pasteurized in-shell eggs are recommended in place of pooled eggs or raw or undercooked shell eggs. If used, raw shell eggs should be fully cooked. If shell eggs are served undercooked, a consumer advisory should be posted in accordance with the Food Code.
- In hospitals, nursing homes, adult or childcare facilities, and senior centers, pasteurized egg products or pasteurized in-shell eggs should be used in place of pooled eggs or raw or undercooked eggs.
- Eggs should be purchased or received from a distributor refrigerated and stored refrigerated at ≤ 45° F (≤7° C) at all times.
- CDC FAQs: Salmonella Enteritidis
- Description of the Steps In a Foodborne Outbreak Investigation
- CDC's Role During a Multi-State Foodborne Outbreak Investigation
- Wright County Egg Conducts Nationwide Voluntary Recall of Shell Eggs Because of Possible Health Risk (August 13, 2010)
CDC's Role in Food Safety
As an agency within the U.S. Department of Health and Human Services (HHS), CDC leads federal efforts to gather data on foodborne illnesses, investigate foodborne illnesses and outbreaks, and monitor the effectiveness of prevention and control efforts. CDC is not a food safety regulatory agency but works closely with the food safety regulatory agencies, in particular with HHS's U.S. Food and Drug Administration (FDA) and the Food Safety and Inspection Service within the U.S. Department of Agriculture (USDA). CDC also plays a key role in building state and local health department epidemiology, laboratory, and environmental health capacity to support foodborne disease surveillance and outbreak response. Notably, CDC data can be used to help document the effectiveness of regulatory interventions.