2018 Salmonella Infections Linked to Gravel Ridge Farms Shell Eggs – Final Update – Outbreak Investigation Updates by Date

October 2, 2018

Since the last update on September 10, 2018, 24 ill people have been added to this investigation.

As of October 1, 2018, 38 people infected with the outbreak strain of Salmonella Enteritidis have been reported from seven states. A list of the states and the number of cases in each can be found on the Map of Reported Cases page.

Illnesses started on dates ranging from June 17, 2018, to August 16, 2018. Ill people range in age from one year to 94, with a median age of 33. Fifty-seven percent of ill people are female. Of 32 people with information available, 10 (31%) have been hospitalized. No deaths have been reported.

Illnesses might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 4 weeks. Please see the Timeline for Reporting Cases of Salmonella Infection for more details.

Investigation of the Outbreak

State and local health officials continue to interview ill people and ask questions about the foods they ate and other exposures in the week before they became ill. Twenty-two of 29 (76%) people interviewed reported eating restaurant dishes made with eggs. This percentage is significantly higher than results from a survey [PDF – 787 KB] of healthy people in which 38% of respondents reported eating any eggs away from home in the week before they were interviewed. These restaurants reported using shell eggs in the dishes eaten by ill people.

FDA and state partners traced the source of the shell eggs supplied to these restaurants. Gravel Ridge Farms in Cullman, Alabama supplied shell eggs to restaurants where 19 of the 22 ill people ate. Eight ill people live in states where Gravel Ridge Farms shell eggs were not sold. Six of these ill people traveled to states where Gravel Ridge Farms shell eggs were sold.

The outbreak strain of Salmonella Enteritidis was identified in environmental samples from Gravel Ridge Farms. Officials in Alabama also collected eggs from the Gravel Ridge Farms facility for testing. The outbreak strain of Salmonella Enteritidis was identified in these eggs.

WGS results show that the Salmonella from the environmental samples and from Gravel Ridge Farms is closely related genetically to the Salmonella from ill people. These results provide more evidence that people in this outbreak got sick from eating shell eggs from Gravel Ridge Farms.

On September 8, 2018, Gravel Ridge Farms recalled cage-free large eggs because they might be contaminated with Salmonella bacteria.

This investigation is ongoing, and CDC will provide updates when more information is available.

September 10, 2018

CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA) are investigating a multistate outbreak of Salmonella Enteritidis infections.

Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. PulseNet is the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC. DNA fingerprinting is performed on Salmonella bacteria isolated from ill people by using techniques called pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). CDC PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks. WGS gives a more detailed DNA fingerprint than PFGE. WGS performed on bacteria isolated from ill people showed that they were closely relatedly genetically. This means that people in this outbreak are more likely to share a common source of infection.

As of September 7, 2018, 14 people infected with the outbreak strain of Salmonella Enteritidis have been reported from two states. A list of the states and the number of cases in each can be found on the Map of Reported Cases page.

Illnesses started on dates ranging from July 10, 2018 to August 7, 2018 Ill people range in age from 1 year to 94, with a median age of 31. Fifty percent are female. Of 9 people with information available, 2 (22%) have been hospitalized. No deaths have been reported.

Illnesses that occurred after August 22, 2018, might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 4 weeks. Please see the Timeline for Reporting Cases of Salmonella Infection for more details.

Investigation of the Outbreak

Epidemiologic and traceback evidence indicates that shell eggs from Gravel Ridge Farms are a likely source of the outbreak.

In interviews, ill people answered questions about the foods they ate and other exposures in the week before they became ill. Thirteen of 14 (93%) people interviewed reported eating restaurant dishes made with eggs. This percentage is significantly higher than results from a survey [PDF – 787 KB] of healthy people in which 38% of respondents reported eating any eggs away from home in the week before they were interviewed. These restaurants reported using shell eggs in the dishes eaten by ill people.

FDA and state partners traced the source of the shell eggs supplied to these restaurants to Gravel Ridge Farms in Cullman, Alabama.

On September 8, 2018, Gravel Ridge Farms recalled cage-free large eggs because they might be contaminated with Salmonella bacteria. Recalled eggs were sold in grocery stores and to restaurants in Alabama, Georgia, and Tennessee. The FDA website has a list of the grocery stores where recalled eggs were sold. Consumers who have any Gravel Ridge Farms cage-free large eggs in their homes should not eat them. Return them to the store for a refund or throw them away. Restaurants and retailers should not serve or sell recalled Gravel Ridge Farms cage-free large eggs.

This investigation is ongoing, and CDC will provide updates when more information is available.