Wright County Egg and Hillandale Farms eggs have caused over 1800 Salmonella illnesses nationally, according to the CDC’s latest update, released today. Significantly, we have still not yet reached the end of the reporting period for this outbreak, which the CDC notes specifically in the summary below. Will confirmed illnesses in the outbreak top 2,000? How many total illnesses are there in this outbreak (confirmed and unconfirmed)? FYI: 38 x 1,800 is 68,400.
The updated summary from the CDC on the egg outbreak:
In July 2010, CDC identified a nationwide sustained 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. This increase began in May 2010 and is evident in the epidemic curve, or epi curve. The number of reports increased substantially in July when the peak of the outbreak appears to have occurred. From May 1 to October 15, 2010, 2010, a total of 3,182 illnesses were reported. However, some cases from this period have not been reported yet, and some of these cases may not be related to this outbreak. Based on the previous 5 years of reports to PulseNet, we would expect approximately 1,369 total illnesses during this same period. This means there are approximately 1,813 reported illnesses that are likely to be associated with this outbreak. Many states have reported increases of this pattern since May. Because of the large number of expected cases during this period, standard methods of molecular subtyping alone are not sufficient to determine which reported cases might be outbreak-associated. CDC is currently evaluating advanced molecular methodologies to see if they help distinguish between outbreak-related cases and sporadic (or background) cases.
Ilnesses that occurred after September 12, 2010 might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This typically takes two to three weeks for Salmonella, but can take up to six weeks. For more details, please see the Salmonella Outbreak Investigations: Timeline for Reporting Cases.
Epidemiologic investigations conducted by public health officials in 11 states since April have identified 29 restaurants or event clusters where more than one ill person with the outbreak strain has eaten. Data from these investigations suggest that shell eggs are a likely source of infections in many of these restaurants or event clusters. Wright County Egg, in Galt, Iowa, was an egg supplier in 15 of these 29 restaurants or event clusters; three are clusters that have been recently reported, but occurred earlier in the outbreak. Traceback investigations have been completed for several of these clusters. A formal traceback was conducted by state partners in California, Colorado, and Minnesota, in collaboration with FDA and CDC, to find a common source of shell eggs. Wright County Egg in Iowa was found as the common source of the shell eggs associated with three of the clusters. Through traceback and FDA investigational findings, Hillandale Farms of Iowa, Inc., was identified as another potential source of contaminated shell eggs contributing to this outbreak. FDA has completed its on-site investigations at both of these firms in Iowa. Evaluation of the investigational data, including review of sampling results and records, continues in order to identify potential sources of contamination, such as feed. FDA’s inspectional observations, in addition to sample results, indicate substantial potential for Salmonella to have persisted in the environment and to have contaminated eggs (see 483 Inspectional Observations on the Egg Recall).