Link Between Dry Pet Food and Human Salmonella Infection

Casey Barton Behravesh, MS, DVM, DrPH, from the National Center for Zoonotic, Vectorborne and Enteric Diseases, and the Epidemic Intelligence Service Program at the Centers for Disease Control and Prevention (CDC), and colleagues report on their study of human Salmonella infections associated with dry pet food in the latest issue of Pediatrics, the journal of the American Academy of Pediatrics.

The researchers investigated an outbreak of Salmonella Schwarzengrund and primarily affecting young children via two multistate case-control studies to determine the source and mode of infections among case-patients with the outbreak strain. Study 1 evaluated household exposures to animals and pet foods, and study 2 examined risk factors for transmission among infant case-patients. Environmental investigations were conducted.

Behravesh and colleagues report that 79 case-patients in 21 states were identified; 48 percent were children aged 2 years or younger. Case-households were significantly more likely than control households to report dog contact and to have recently purchased manufacturer X brands of dry pet food. Illness among infant case-patients was significantly associated with feeding pets in the kitchen. The outbreak strain was isolated from opened bags of dry dog food produced at plant X, fecal specimens from dogs that ate manufacturer X dry dog food, and an environmental sample and unopened bags of dog and cat foods from plant X. More than 23 000 tons of pet foods were recalled. After additional outbreak-linked illnesses were identified during 2008, the company recalled 105 brands of dry pet food and permanently closed plant X.

The researchers conclude that dry dog and cat foods manufactured at plant X were linked to human illness for a three-year period, and emphasize that this outbreak highlights the importance of proper handling and storage of pet foods in the home to prevent human illness, especially among young children.

Reference: Behravesh CB, et al. Human Salmonella Infections Linked to Contaminated Dry Dog and Cat Food, 20062008. Pediatrics. August 9, 2010.