Yersiniosis – Causes, Symptoms and Treatment

What is Yersiniosis?

Yersiniosis is an infectious disease caused by bacteria of the genus Yersinia. The two species most relevant to human health are Yersinia enterocolitica and Yersinia pseudotuberculosis, both of which primarily affect the gastrointestinal tract. Yersiniosis is a notifiable disease in many countries and occurs throughout the year, with higher incidence rates during winter months.

Causes and Transmission

The infection is most commonly transmitted through the consumption of contaminated food, particularly:

• Raw or undercooked pork (the most frequent source)
• Unpasteurized milk and dairy products
• Contaminated drinking water
• Raw vegetables and salads

Direct transmission from animals to humans or between humans is also possible, though less common. A notable characteristic of Yersinia bacteria is their ability to multiply even at refrigerator temperatures, setting them apart from many other foodborne pathogens.

Symptoms

The clinical presentation varies depending on the age and immune status of the affected individual, as well as the specific Yersinia species involved:

• Diarrhea (watery or bloody)
• Abdominal pain, often in the lower right abdomen (which can mimic appendicitis)
• Fever
• Nausea and vomiting
• General malaise

In older children and adults, mesenteric lymphadenitis (inflammation of the lymph nodes in the abdomen) may develop, closely resembling appendicitis. Complications such as reactive arthritis, erythema nodosum (painful skin nodules), or sepsis (bloodstream infection) are possible but rare.

Diagnosis

Diagnosis is typically confirmed by laboratory identification of the pathogen from stool, blood, or other body fluids:

• Stool culture: Growing the bacteria from a stool sample in the laboratory
• Serology: Detection of specific antibodies in the blood
• PCR (Polymerase Chain Reaction): Molecular detection of bacterial genetic material

Because the symptoms resemble those of other gastrointestinal illnesses, laboratory testing is essential to ensure accurate diagnosis and appropriate treatment.

Treatment

In uncomplicated cases, no specific treatment is usually required. The illness typically resolves on its own within one to three weeks. Key supportive measures include:

• Adequate fluid intake to compensate for losses caused by diarrhea
• Rest and physical recovery

In severe cases, complications, or immunocompromised patients, antibiotic therapy may be necessary. Suitable antibiotics include fluoroquinolones, cotrimoxazole, or third-generation cephalosporins, to be taken under medical supervision.

Prevention

The following hygiene measures are recommended to prevent yersiniosis:

• Always cook meat thoroughly, especially pork
• Store food at appropriate temperatures
• Wash hands regularly and thoroughly, especially after handling raw meat
• Clean kitchen utensils carefully after contact with raw meat
• Avoid consuming unpasteurized milk

References

1. Robert Koch Institute (RKI): Yersiniosis Fact Sheet. RKI Advisory, Berlin, updated edition 2023. Available at: https://www.rki.de
2. World Health Organization (WHO): Foodborne diseases. Available at: https://www.who.int
3. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th edition, Elsevier, 2020. Chapter on Yersinia infections.