According to a Dec. 2 update from the U.S. Centers for Disease Control and Prevention (CDC), the Salmonella outbreak this past summer linked to recalled pork products “appears to be over.” CDC stated that 192 people from five states were reported to be infected with the outbreak strains of Salmonella I 4,[5],12:i:- (188) and Salmonella Infantis (4). Thirty people were hospitalized, and no deaths were reported. Most of those sickened were from Washington state. PigsFeedingMainThe number of ill people reported from each state was as follows: Alaska (1), California (2), Idaho (2), Oregon (3), and Washington (184), CDC noted. Most of the ill people infected in states other than Washington had traveled there in the week before their illness started. Among people for whom information was available, illnesses started on dates ranging from April 25, 2015, to Sept. 25, 2015, the agency reported. Ill people ranged in age from less than 1 year to 90, with a median age of 35. Fifty-one percent of ill people were female. Epidemiologic, laboratory, and traceback findings identified pork produced by Kapowsin Meats of Graham, WA, as the likely source of this outbreak, CDC stated. The company recalled 116,262 pounds of whole hogs for barbecue on Aug. 13, 2015, and that recall was expanded on Aug. 27 to include another 523,380 pounds of whole hogs and related products. The product was shipped to individuals, retail locations, institutions, and distributors in Alaska, Oregon, and Washington. While Kapowsin Meats took steps to address sanitary conditions at their facility after the original recall, USDA-FSIS conducted intensified sampling. The intensified sampling identified Salmonella I 4,[5],12:i:- and Salmonella Infantis on whole pigs for barbeque, on associated pork products, and throughout the facility, CDC stated. The agency stated that consumers should check their homes and freezers for the recalled pork products and should not cook or eat them. Retailers should not sell these products and restaurants should not serve them, CDC stated. The agency’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory conducted antibiotic-resistance testing on clinical isolates collected from 10 ill people infected with one of the outbreak strains of Salmonella I 4,[5],12:i:-. All 10 isolates were multi-drug resistant. This included resistance to ampicillin, streptomycin, sulfisoxazole, and tetracycline. Antibiotic resistance may be associated with increased risk of hospitalization, development of a bloodstream infection, or treatment failure in patients, CDC stated. The Washington State Department of Health (DOH), Public Health–Seattle  & King County (PHSKC), several states, CDC, and the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS) investigated this outbreak.

Public health investigators used the PulseNet system to identify illnesses that may be part of this outbreak. CDC coordinates PulseNet, the national subtyping network of public health and food regulatory agency laboratories. DNA “fingerprinting” is performed on Salmonella bacteria isolated from ill people using techniques called pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). WGS gives a more detailed DNA fingerprint than PFGE. PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks of enteric illness. Six DNA fingerprints (outbreak strains) were included in this outbreak investigation. The six strains are rare in Washington but more common in other U.S. states. WGS was performed on clinical isolates from ill people in other states who were suspected to be part of the outbreak. Some of these isolates were found to be closely genetically related to clinical isolates from Washington. This close association provided additional evidence that illnesses that occurred in other states were related to the illnesses in Washington. The National Antimicrobial Resistance Monitoring System (NARMS) is a U.S. public health surveillance system that tracks antibiotic resistance in foodborne and other enteric bacteria found in people, raw meat and poultry, and food-producing animals. NARMS is a partnership among the CDC, the U.S. Food and Drug Administration (FDA), USDA, and state and local health departments. Salmonella is an important cause of human illness in the United States. For more information about Salmonella and steps that people can take to reduce their risk of infection, visit CDC’s Salmonella webpage here.

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