Yersiniosis

• Pathogens: Yersinia enterocolitica, Yersinia pseudotuberculosis

  • Gram-negative, rod-shaped, pleomorphic bacteria; obligate pathogens

  • High infective dose required (109 pathogens)

• Transmission

  • Foodborne (e.g., raw/undercooked pork, unpasteurized milk products)

  • Contaminated water

  • Direct/indirect contact with infected animal (e.g., dogs, pigs, rodents) and/or their feces

• Incubation period: 4–6 days

• Duration: 12–22 days

• Low-grade fever, vomiting

• Invasive diarrhea (may be bloody in severe cases)

• Pseudoappendicitis: mesenteric lymphadenitis, particularly in the ileum, with typical signs of appendicitis

• Direct pathogen detection in culture or cold enrichment

• Supportive therapy for gastroenteritis: e.g., bland diet, oral rehydration therapy

• Antibiotic therapy: Treatment should be based on culture susceptibility testing.

  • Indications: severe cases

  • Recommended regimens

    • Trimethoprim/sulfamethoxazole

    • OR fluoroquinolones: e.g., ciprofloxacin

    • OR third-generation cephalosporins: e.g., cefotaxime

Particularly common in patients with HLA-B27

• Reactive arthritis

• Erythema nodosum

• Acute abdomen: appendicitis, bowel perforation, toxic megacolon, cholangitis

• Bacteremia