The US Centers for Disease Control and Prevention (CDC) are working alongside health officials in 29 states to investigate an outbreak of multidrug-resistant Salmonella Infantis infections. This outbreak has been linked to raw chicken products, adding yet another poultry-related outbreak to the list.
As of October 15, 2018, 92 illnesses have been reported across 29 states, with the onset of infection occurring between January 19, 2018 through September 9, 2018.
The ages of those who have fallen ill range from less than 1 year to 105 years with a median age of 36; at this time, 69% of the ill are female. Of the 62 individuals for which there was available information, there have been 21 hospitalizations with no deaths reported thus far.
As part of the investigation, health officials interviewed 54 individuals about consumption and exposure in the week prior to falling ill. Forty-eight of the individuals reported preparing or eating chicken products that were purchased raw, such as ground chicken, chicken pieces, and whole chickens, according to the CDC. The health officials have not identified a common brand or store where the products were purchased at this time.
One individual reported that they fell ill after pets living in their home ate raw food containing ground chicken. Another Salmonella case was reported in an individual working in a facility that processes or raises chickens.
As part of the epidemiologic investigation, samples were collected from ill individuals and processed using whole genome sequencing (WGS). The US Department of Agriculture Food Safety Inspection Service (USDA-FSIS) also collected samples from facilities that process raw chicken. The outbreak strain, Salmonella Infantis, was detected in products from 58 facilities.
WGS analysis indicated that the Salmonella in the human samples was closely related to the Salmonella from the products at the processing facilities, indicating that the individuals in the outbreak likely became sick from handling or consuming raw chicken.
Due to the widespread presence of the outbreak strain, it is possible that the strain is present in live chickens and raw chicken products.
WGS analysis indicated that 43 ill individuals and 68 product or environmental samples predicted resistance to antibiotics including “ampicillin, ceftriaxone, chloramphenicol, ciprofloxacin, fosfomycin, gentamicin, hygromycin, kanamycin, nalidixic acid, streptomycin, sulfamethoxazole, tetracycline, and trimethoprim-sulfamethoxazole,” according to the CDC.
As a result, clinicians in the area should be aware that infections may be hard-to-treat due to resistance, and, as such, may require alternate antibiotics.
The CDC and USDA-FSIS are working in collaboration with chicken raising and processing plants to create awareness about the outbreak and discuss methods of reducing Salmonella infection. Health officials will continue to investigate ways to reduce the prevalence of this strain in live chickens and raw chickens.
This is an ongoing investigation and the CDC will provide updates as they become available.
For the most recent case counts in the Multidrug-Resistant Salmonella Infantis Infections linked to Chicken Products, check out the Contagion® Outbreak Monitor.