Yersiniosis

This is infection with a member of the Yersinia species. There are three major human pathogens;

• Yersinia pestis, which causes plague
• Yersinia pseudotuberculosis which causes mesenteric lymphadenitis
• Yersinia enterocolitica which causes enterocolitis

Summary: Yersinia pseudotubercolosis and Yersinia entercolitica

Cause:

• Yersinia enterocolitica and Yersinia pseudotuberculosis

Reservoir:

• Asymptomatic carriage in the gastrointestinal tract of wild and domesticated animals and birds, particularly pigs for Y. enterocolitica

Epidemiology:

• most commonly seen in those less than 15 years of age
• seasonal variation occurs - Y. pseudotuberculosis is more common in winter and Y. enterocolitica is more common from June to November

Transmission:

• Faecal-oral:
  • consumption of contaminated food or water, particularly pork or pork products. A wide variety of foodstuffs have been implicated in cases and outbreaks
• person-to-person: particularly within nurseries, schools and healthcare settings
• direct contact with animals
• Via contaminated blood products

Incubation period:

• Y. enterocolitica: usually 3-7 days with extremes of 1-12 days reported
• Y. pseudotuberculosis: range of 2-25 days reported (median 5-8 days)

Common clinical features:

• Y. enterocolitica:
  - watery diarrhoea, abdominal pain, fever
  - duration: 2 days to 6 weeks
  - complications: reactive arthritis, erythema nodosum, septicaemia
• Y. pseudotuberculosis:
  - mesenteric adenitis, fever, abdominal pain often mimicking appendicitis
  - duration: 1-37 days (average 18 days)
  - complications: reactive arthritis, erythema nodosum, acute renal failure

Infectivity:

• excretion of the organism in stool may persist for several months after infection but infectivity decreases substantially after the first 4 days or so

Reference:

• PHE (2019). Recommendations for the Public Health Management of Gastrointestinal Infections