Mar 6, 2013 (CIDRAP News) – Four more illnesses have been reported in a multistate Salmonella Heidelberg outbreak linked to a brand of retail chicken, and lab testing in Washington has detected the outbreak strain on products from patients' homes, the US Centers for Disease Control and Prevention (CDC) said yesterday.
The new cases push the total in the outbreak that has been simmering since last June to 128. Epidemiologic and trace-back investigations in Oregon and Washington previously found that most of the patients ate chicken before they got sick and that Foster Farms brand chicken was the most likely source.
The new findings on chicken samples added to the evidence that the company's chicken is probably the source of the outbreak, and tests found that some of the patient isolates and one from a chicken sample were resistant to antibiotics.
In its first report on the outbreak on Feb 14 the CDC declined to list all of the affected states until investigators determined that the cases were linked to the outbreak, but in the new update it names 13 affected states. Most cases are from Washington (56) and Oregon (39), but others reporting infections are Alabama, Alaska, California, Hawaii, Idaho, Massachusetts, Montana, New York, Utah, Virginia, and West Virginia.
These states have reported 1 to 11 cases each. The four newest illnesses were from Alabama, California, and Oregon.
The most recent illness onset was Feb 4. Of 103 patients with available information, 32 were hospitalized. No deaths have been reported.
Testing by the Washington State Public Health Laboratories has identified the outbreak strain in four intact samples of chicken collected from three patients' homes, according to the report.
Also, the CDC said data from its National Antimicrobial Resistance Monitoring System (NARMS) from 2002 to 2011 show that of 233 retail samples that tested positive for Salmonella Heidelberg, 48 (21%) matched the outbreak strain. All but one of the matching outbreak strains was in chicken samples from Foster Farms.
The NARMS retail meat surveillance program is a joint effort of the Food and Drug Administration (FDA), CDC, and health departments in 11 states that provides information on bacterial isolates in chicken, ground turkey, ground beef, and pork chops. The state labs send the isolates they collect from the samples to the FDA for serotype identification, antimicrobial susceptibility testing, and genetic analysis.
So far there has been no recall, and Salmonella isn't considered an adulterant on raw chicken. The CDC has said it's not unusual for raw poultry from any producer to have Salmonella, which underscores the importance of following key food safety steps when handling the product in the home, such as avoiding cross-contamination of other foods.
CDC testing on samples from 14 of the sick patients found that two isolates were resistant to multiple antibiotics. Similar testing on isolates from the four retail samples found that one was resistant to gentamicin, streptomycin, and sulfisoxazole.
The CDC said infections with resistant Salmonella strains may be more severe or difficult to treat.
Mar 5 CDC outbreak update
Feb 15 CIDRAP News story "Multistate Salmonella outbreak tied to chicken sickens 124"