A21.3 Gastrointestinal tularemia

Name of the Condition

• Gastrointestinal tularemia

Summary

Gastrointestinal tularemia is a localized form of tularemia, a bacterial infection caused by Francisella tularensis. It is characterized by gastrointestinal symptoms resulting from ingestion of the bacteria, typically through contaminated food or water. This form of the disease may present with abdominal pain, nausea, vomiting, and diarrhea, and symptoms can range from mild to severe depending on the bacterial load and host factors.

Causes

Gastrointestinal tularemia is caused by the bacterium Francisella tularensis. Infection occurs when the bacteria are ingested, often through consumption of contaminated meat (e.g., undercooked wild game) or water from sources harboring the organism. The bacteria colonize the gastrointestinal tract, leading to localized inflammation and systemic symptoms.

Risk Factors

• Ingestion of undercooked or raw meat from infected animals (e.g., rabbits, rodents).
• Consumption of water from untreated sources in endemic areas.
• Occupational or recreational activities involving wildlife (e.g., hunting, farming) where food or water contamination is possible.
• Living in or traveling to regions with known Francisella tularensis activity.

Symptoms

• Abdominal pain, cramping, or discomfort.
• Nausea and vomiting.
• Diarrhea (which may be bloody in severe cases).
• Fever and chills.
• Loss of appetite or weight.

Diagnosis

Diagnosis of gastrointestinal tularemia involves a combination of clinical evaluation, exposure history, and laboratory testing. Healthcare providers may order blood cultures, serologic tests for Francisella tularensis antibodies, or polymerase chain reaction (PCR) assays to detect bacterial DNA. Stool samples may be analyzed to rule out other gastrointestinal pathogens, and imaging studies (e.g., abdominal ultrasound) can assess for complications like abscesses.

Treatment Options

Treatment typically involves antibiotics, with streptomycin or gentamicin being first-line therapies for severe cases. Oral antibiotics such as doxycycline or ciprofloxacin may be used for milder infections. Supportive care, including hydration and electrolyte management, is important for managing gastrointestinal symptoms. The duration of treatment is usually 10–14 days, depending on the severity of the infection.

Prognosis and Follow-Up

With prompt antibiotic treatment, most patients recover fully. Delayed or inadequate treatment can lead to prolonged illness or complications. Follow-up may include monitoring for resolution of symptoms and repeat testing if clinical improvement is not observed. Patients should be advised to complete the full course of antibiotics to prevent relapse.

Complications

• Dehydration due to persistent vomiting or diarrhea.
• Bacteremia (spread of bacteria to the bloodstream), which can lead to sepsis.
• Abscess formation in the gastrointestinal tract or other organs.
• Chronic fatigue or malaise in some cases.

Lifestyle & Prevention

• Cook wild game meat thoroughly to kill bacteria.
• Avoid consuming untreated water in endemic areas; use boiled or filtered water.
• Practice good hand hygiene, especially after handling animals or their tissues.
• Wear protective gloves when skinning or processing wild animals.
• Use insect repellent to reduce exposure to biting arthropods that may carry the bacteria.

When to Seek Professional Help

Seek medical attention if you experience severe abdominal pain, persistent vomiting, bloody diarrhea, high fever, or signs of dehydration (e.g., dizziness, reduced urination). Prompt evaluation is important to prevent complications and ensure appropriate treatment.

Tips for Medical Coders

When coding for gastrointestinal tularemia (ICD-10-CM code A21.3), ensure documentation supports the gastrointestinal presentation, including symptoms like abdominal pain, nausea, or diarrhea, and a history of exposure (e.g., contaminated food/water). Verify that the code aligns with the clinical scenario and that any associated conditions (e.g., dehydration) are coded separately if applicable.