Facultative anaerobic gram-negative coccobacilli in the genus Yersinia (most commonly Yersinia enterocolitica serogroups O:3; O:5,27; O:8; and O:9).
Consuming or handling contaminated food, most commonly raw or undercooked pork products; milk that was not pasteurized, inadequately pasteurized, or contaminated after pasteurization; or untreated water. Also transmitted by direct or indirect contact with animals.
Most common in northern Europe (particularly Scandinavia), Japan, and Canada. In temperate climates, risk is higher in cooler months. The incidence among travelers to developing countries is generally low. A US study found that approximately 6% of Y. enterocolitica infections were travel associated. People with high iron levels are at higher risk of infection and severe disease.
Incubation period is 4–6 days (range, 1–14 days). Symptoms include fever, abdominal pain (may mimic appendicitis), and diarrhea (may be bloody and can persist for several weeks). Necrotizing enterocolitis has been described in young infants. Reactive arthritis affecting the wrists, knees, and ankles can occur, usually 1 month after the initial diarrhea episode, resolving after 1–6 months. Erythema nodosum can also occur, manifesting as painful, raised red or purple lesions along the trunk and legs, usually resolving spontaneously within 1 month.
Isolation of the organism from stool, blood, bile, wound, throat swab, mesenteric lymph node, cerebrospinal fluid, or peritoneal fluid. If yersiniosis is suspected, the clinical laboratory should be notified and instructed to culture on CIN agar.
Most infections are self-limited. Antibiotics should be given for moderate to severe cases. Y. enterocolitica isolates are usually susceptible to trimethoprim-sulfamethoxazole, aminoglycosides, third-generation cephalosporins, fluoroquinolones, and tetracyclines; they are typically resistant to first-generation cephalosporins and most penicillins. Antimicrobial therapy has no effect on postinfectious sequelae.
Avoid eating raw or undercooked pork products, unpasteurized milk products, and untreated water (see Chapter 2, Food & Water Precautions). Wash hands with soap and water before eating and preparing food, after contact with animals, and after handling raw meat.
CDC website: www.cdc.gov/yersinia
L. Hannah Gould, Cindy R Friedman