CDC Recalls Employees to Fight Drug-Resistant Salmonella Outbreak
By Stan Deresinski, MD, FACP, FIDSA, Clinical Professor of Medicine, Stanford University, Hospital Epidemiologist, Sequoia Hospital, Redwood City, CA, Editor of Infectious Disease Alert
As a result of the shutdown of the federal government, approximately 9000 of the 14,000 CDC employees were placed on furlough. On October 8th, however, 30 of the furloughed employees were recalled to assist in the response to an epidemic of Salmonella Heidelberg infections.
A total of 317 individuals infected with the outbreak strains of Salmonella heidelberg have been reported as of October 11, 2013.1 While cases have occurred in 20 states and Puerto Rico, most of the ill persons (73%) have been reported from California. Among 310 persons for whom information was available, illness onset dates range from March 1, 2013 to September 26, 2013. Those affected range in age from less than 1 year to 93 years, with a median age of 20 years; 51% were male. Hospitalization was felt necessary for 79 of 189 (42%) individuals for whom the information was available. Bloodstream infection was detected in 13% — a proportion more than twice as great as normally seen in Salmonella infections. There have been no deaths to date.
Based on pulsed field gel electrophoresis, 7 strains of S. heidelberg have been identified as being involved in the outbreak. Resistance to commonly used antibiotics was frequent and multidrug resistance was seen in some. The epidemic strains were traced back, using classical and molecular epidemiology, to ingestion of chicken processed by Foster Farms.
Salmonella and chicken go together. A recent analysis of raw chicken purchased from retail outlets in central Pennsylvania found Salmonella in 84 of 378 (22%) samples.2 Furthermore, 26 of the Salmonella isolates were resistant to 3 or more antibiotics, and with frequently reduced susceptibility to ceftriaxone. The high incidence of hospitalization, however, distinguishes this outbreak from most others and suggests the possibility that the strains involved have enhanced virulence.
Reference
- 1.Centers for Disease Control and Prevention. Multistate Outbreak of Multidrug-Resistant Salmonella Heidelberg Infections Linked to Foster Farms Brand Chicken: http://www.cdc.gov/salmonella/heidelberg-10-13/index.html
- 2. M'ikanatha NM, Sandt CH, Localio AR, et al. Multidrug-resistant Salmonella isolates from retail chicken meat compared with human clinical isolates. Foodborne Pathog Dis 2010;7:929-34.
