Another month of the Salmonella Heidelberg outbreak linked to Foster Farms raw chicken has added 43 people with the illness to the official case count. The new illnesses increased the number of individuals infected with the outbreak strains of Salmonella Heidelberg to 524 in 25 states and Puerto Rico. The illnesses in the outbreak, which has now spanned more than one year, occurred between March 1, 2013, and April 7, 2014. Most of the illnesses — 76 percent — have been reported in California. In the past month, the new illnesses were reported from five states: Arizona (2), California (34), Michigan (1), Texas (2) and Washington (1). In the latest report posted Wednesday, the federal Centers for Disease Control and Prevention says that, for 518 persons for whom information is available, illness onset dates range from March 1, 2013, to March 18, 2014. Ill persons range in age from less than 1 year to 93 years, with a median age of 18 years. Fifty-one percent of ill persons are male. Among 437 persons with available information, 162 (37 percent) reported being hospitalized. Thirteen percent of ill persons have developed blood infections as a result of their illness. Typically, approximately 5 percent of persons ill with Salmonella infections develop blood infections. No deaths related to this outbreak have been reported. Illnesses that began after March 8, 2014, might not be reported yet due to the time it takes between when a person becomes ill and when the illness is reported. This can take an average of two to four weeks. The outbreak is linked to California-based Foster Farms through interviews with those who were infected. Among those who could remember brand information, 119 (or 74 percent) of 161 people named Foster Farms or another brand likely produced by Foster Farms. CDC says it is working closely with USDA’s Food Safety and Inspection Service, which it claims “is assessing interventions implemented at Foster Farms facilities to prevent future illnesses.” Foster Farms has not recalled any product associated with the ongoing outbreak. In a press statement released Wednesday, Foster Farms noted that the company was “steadily reducing Salmonella levels” at its facilities. The statement continued: “Foster Farms is committed to leadership in food safety and producing the safest chicken on the West Coast. Since October 2013, Foster Farms has developed a multiple-hurdle approach to reduce or eliminate Salmonella at each stage of production – from screening breeder flocks before entering the Foster Farms system, to farms where the birds are raised, to the plants where the chicken is processed as a whole bird and when it is cut into parts. As a result, the company has steadily reduced the prevalence of Salmonella at the parts level toward a goal of less than 10 percent – well below the USDA-measured industry benchmark of 25 percent.”
Meanwhile, CDC’s National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS) laboratory is doing antimicrobial susceptibility testing on clinical isolates collected from ill persons infected with any of the seven outbreak strains. Of 61 isolates tested to date, 38 (62 percent) exhibited resistance to one or more antibiotics. Nineteen (31 percent) of the 61 isolates were multidrug-resistant. To date, isolates collected from ill persons were resistant to combinations of the following antibiotics: ampicillin, chloramphenicol, gentamicin, kanamycin, streptomycin, sulfisoxazole and tetracycline. CDC says that, although these antibiotics are not typically used to treat Salmonella bloodstream infections or other severe Salmonella infections, antibiotic resistance can be associated with a higher risk of hospitalization in infected individuals. Isolates collected from ill persons reported in 2014 have exhibited similar patterns of antibiotic resistance as isolates collected from ill persons reported in 2013.