B66.3 Fascioliasis

Name of the Condition

• Fascioliasis

Summary

Fascioliasis is a parasitic infection caused by the liver fluke Fasciola hepatica or Fasciola gigantica. The infection primarily affects the liver and bile ducts, leading to inflammation and potential long-term complications. It is commonly associated with the consumption of raw or undercooked aquatic plants or watercress containing fluke larvae. The condition may be asymptomatic in mild cases but can progress to more severe disease in chronic infections.

Causes

The infection is caused by ingesting the larvae of Fasciola species, which are present in raw or undercooked aquatic plants (e.g., watercress) or contaminated water. The larvae mature into adult flukes in the human liver, where they attach and reproduce, releasing eggs that are excreted in feces. Contaminated water sources or food preparation practices that involve uncooked aquatic plants facilitate transmission.

Risk Factors

• Consumption of raw or undercooked aquatic plants (e.g., watercress) from endemic regions.
• Residing in or traveling to areas where Fasciola infection is common (e.g., South America, the Middle East, Southeast Asia).
• Poor sanitation or lack of access to safe food and water.
• Occupational exposure to contaminated plants or water (e.g., farming, foraging).

Symptoms

• Abdominal pain, particularly in the upper right quadrant.
• Nausea, vomiting, or diarrhea.
• Fatigue, fever, or general malaise.
• Jaundice or liver dysfunction in severe cases.
• Eosinophilia (elevated eosinophil count) is common.

Diagnosis

Diagnosis is typically based on a combination of clinical presentation, exposure history, and laboratory findings. Stool or bile samples may be examined for fluke eggs. Serological tests (e.g., ELISA) can detect antibodies to Fasciola. Imaging studies (e.g., ultrasound, CT) may reveal liver lesions or bile duct abnormalities. In some cases, a liver biopsy may be performed to identify adult flukes or eggs.

Treatment Options

Treatment usually involves antiparasitic medications, such as triclabendazole, which is the first-line therapy. Alternative agents (e.g., bithionol) may be used if triclabendazole is unavailable. Supportive care, including pain management and hydration, may be necessary for severe cases. Follow-up testing is recommended to confirm treatment efficacy.

Prognosis and Follow-Up

With appropriate treatment, the prognosis is generally good, especially in early or mild cases. Chronic infections may lead to long-term liver damage or bile duct obstruction. Follow-up monitoring, including repeat serology or imaging, may be necessary to assess resolution of infection or complications. Patients should be advised to avoid re-exposure to contaminated sources.

Complications

• Chronic liver inflammation or fibrosis.
• Bile duct obstruction or cholangitis.
• Gallbladder disease.
• Severe anemia or malnutrition in prolonged cases.

Lifestyle & Prevention

• Avoid consuming raw or undercooked aquatic plants (e.g., watercress) from endemic areas.
• Ensure water sources are safe for drinking or cooking.
• Practice good hygiene, including handwashing after handling plants or soil.
• Cook aquatic plants thoroughly before consumption.
• Educate communities in endemic regions about transmission risks.

When to Seek Professional Help

Seek medical attention if you experience persistent abdominal pain, jaundice, fever, or unexplained fatigue, especially after potential exposure to contaminated water or plants. Early diagnosis and treatment improve outcomes and reduce complications.

Tips for Medical Coders

When coding for fascioliasis, use ICD-10-CM code B66.3. Ensure documentation supports the diagnosis, including clinical findings, exposure history, and diagnostic test results. Note that B66.3 is specific to fascioliasis and should not be confused with other fluke infections (e.g., opisthorchiasis, clonorchiasis). Verify that the code aligns with the patient’s clinical presentation and any associated complications.