Yersiniosis: Causes, Symptoms and Treatment

What is Yersiniosis?

Yersiniosis is an infectious disease caused by bacteria of the genus Yersinia. The species most commonly responsible for human illness are Yersinia enterocolitica and Yersinia pseudotuberculosis. The disease primarily affects the gastrointestinal tract and occurs worldwide, with higher prevalence in temperate and colder climates.

Causes and Transmission

Yersinia bacteria are primarily transmitted through contaminated food. The most common sources include:

• Raw or insufficiently cooked pork (especially organ meats)
• Unpasteurized milk and dairy products
• Contaminated drinking water
• Direct contact with infected animals (e.g., pets or livestock)
• Fecal-oral transmission from person to person

Yersinia bacteria are unusually cold-tolerant and can multiply at refrigerator temperatures (around 4 °C / 39 °F), making them a particular challenge in food safety.

Symptoms

The incubation period is typically 1 to 11 days. The most common symptoms of yersiniosis include:

• Diarrhea (often watery, occasionally bloody)
• Abdominal pain (often on the lower right side, which can be confused with appendicitis)
• Fever
• Nausea and vomiting
• General malaise

In older children and adults, the condition can mimic appendicitis due to pain localized in the lower right abdomen. In rare cases, particularly in immunocompromised individuals, the bacteria can spread through the bloodstream, causing sepsis or infection of other organs.

Complications

Possible complications following yersiniosis include:

• Reactive arthritis (joint inflammation as an immune-mediated response)
• Erythema nodosum (painful skin nodules, more common in women)
• Rarely: thyroiditis or hepatitis

Diagnosis

Yersiniosis is typically diagnosed by detecting Yersinia bacteria in stool samples. Common diagnostic methods include:

• Stool culture (microbiological cultivation of bacteria)
• PCR testing (molecular pathogen detection)
• Blood culture in cases of suspected sepsis
• Serological tests (antibody detection in blood) for persistent or complicated cases

Because Yersinia bacteria require special culture conditions, it is important to explicitly inform the laboratory of any clinical suspicion of yersiniosis.

Treatment

In otherwise healthy adults and children, yersiniosis typically resolves without specific treatment within 1 to 3 weeks. Management focuses on:

• Adequate fluid intake to replace fluids lost through diarrhea
• Symptomatic treatment (e.g., fever-reducing medications)

Antibiotic therapy is necessary in severe cases, in immunocompromised patients, or when complications such as sepsis occur. Antibiotics used may include trimethoprim-sulfamethoxazole, fluoroquinolones, or third-generation cephalosporins, always as prescribed by a physician.

Prevention

The following measures are recommended to prevent yersiniosis:

• Thoroughly cooking pork and other meat products
• Consuming only pasteurized milk and dairy products
• Washing hands thoroughly after handling raw meat or animals
• Ensuring safe drinking water
• Avoiding cross-contamination in the kitchen

References

1. Robert Koch Institute (RKI): Yersiniosis. RKI Advisory for Physicians. Available at: https://www.rki.de (2023)
2. World Health Organization (WHO): Foodborne diseases. Yersinia. Available at: https://www.who.int
3. Bottone EJ. Yersinia enterocolitica: the charisma continues. Clinical Microbiology Reviews. 1997;10(2):257-276.