Federal and state health officials who are investigating a multistate outbreak of multidrug-resistant Salmonella linked to a variety of raw turkey products and based on detection in live birds are warning that the strain might be widespread in the turkey industry.
So far, 90 infections from Salmonella Reading have been reported in 26 states, according to an announcement today from the US Centers for Disease Control and Prevention (CDC).
Salmonella outbreaks have been linked to turkey products in the past, especially ground turkey. In 2011 a Salmonella Heidelberg outbreak linked to ground turkey sickened at least 136 people in 34 states. The same year, a Salmonella Hadar outbreak linked to turkey burgers resulted in at least 12 infections in 10 states. The strains in both outbreaks were resistant to several antibiotics.
The federal government doesn't classify Salmonella as an adulterant in meat, but food safety groups have called for the US Department of Agriculture (USDA) to classify certain antibiotic-resistant strains as adulterants.
First illnesses reported in November
Cases that are part of the outbreak are widely distributed throughout the country, including Alaska and Hawaii. Minnesota has 13 cases, the most of any state.
Illness onsets range from Nov 20, 2017, to Jun 29. Sick patients range in age from younger than 1 year to 91. Females make up 61% of the sick patients.
Of 78 people with available information, 40 (51%) were hospitalized. No deaths have been reported.
Epi, lab investigation findings
Interviews with sick patients suggest the contaminated products involved different turkey brands and products—including ground turkey, turkey pieces, and whole turkey—that were bought from many different locations. Two people sickened in the outbreak are from a household where raw turkey pet food was fed to pets.
Three of the patients interviewed worked at a facility that raises turkeys or lived with someone who did.
The CDC said the outbreak strain has been found in raw turkey pet food in Minnesota, raw turkey samples from 19 slaughter and 6 processing establishments, and from live turkeys in several states. Samples from slaughter and process facilities were tested as part of USDA Food Safety and Inspection Service (FSIS) routine testing for Salmonella.
Whole-genome sequencing suggests that the Salmonella from the samples is closely related to the strain isolated from sick patients.
Genetic sequencing tests didn't identify predicted resistance in 68 isolates from patient, food, and animal samples, but 33 isolates from people and 49 samples from food and animals contained resistance genes to all or some all of the following antibiotics: ampicillin, streptomycin, sulfamethoxazole, tetracycline, gentamicin, and kanamycin.
The CDC also said antibiotic susceptibility testing of four isolates through its National Antimicrobial Resistance Monitoring System (NARMS) testing confirmed the findings. However, it added that the resistance won't likely affect antibiotic treatment choice for most people, because the drugs in the resistance profile aren't typically used to treat Salmonella infections.
Investigators have not identified a common supplier of raw turkey products or live turkeys. The outbreak strain's presence in both suggests that it might be widespread in the turkey industry, the CDC said, adding that it and the FSIS have shared the information with the turkey industry and asked about steps they may take at the farm and processing levels to reduce contamination.
The CDC urged consumers to always handle raw turkey carefully and cook it thoroughly to prevent foodborne illness. The agency isn't advising consumers to avoid eating properly cooked turkey or that retailers stop selling raw turkey products.
Jul 19 CDC outbreak announcement
Jul 19 USDA FSIS notice