B81.3 Intestinal angiostrongyliasis

Name of the Condition

• Intestinal angiostrongyliasis

Summary

Intestinal angiostrongyliasis is an infection caused by parasitic nematodes of the genus Angiostrongylus. These worms primarily affect the intestinal tract, leading to inflammation and gastrointestinal symptoms. The condition occurs after ingesting larvae or eggs of the parasite, which mature in the intestinal mucosa and can cause tissue damage. Clinical presentation varies based on parasite load and host immune response.

Causes

The infection is caused by ingesting Angiostrongylus larvae or eggs, typically through contaminated food or water. Common sources include raw or undercooked snails, slugs, or other intermediate hosts, as well as produce contaminated with soil containing parasite larvae. The larvae penetrate the intestinal wall, triggering an inflammatory response.

Risk Factors

• Consumption of raw or undercooked snails, slugs, or other intermediate hosts.
• Eating unwashed produce from endemic regions.
• Exposure to soil or water contaminated with Angiostrongylus larvae.
• Poor sanitation and hygiene practices in areas with high parasite prevalence.
• Travel to regions where the parasite is endemic.
• Weakened immune system, which may increase susceptibility to infection.

Symptoms

• Abdominal pain or cramping.
• Nausea and vomiting.
• Diarrhea, which may be chronic or intermittent.
• Weight loss or malnutrition.
• Fatigue or weakness.
• Eosinophilia (elevated eosinophil count in blood).

Diagnosis

Diagnosis is based on clinical presentation, history of exposure to potential sources (e.g., raw snails or contaminated produce), and laboratory findings. Stool samples may be examined for parasite eggs or larvae, though detection can be challenging. Serological tests or imaging may be used to support the diagnosis, especially if eosinophilia is present.

Treatment Options

Treatment typically involves anthelmintic medications, such as albendazole or mebendazole, to target the parasite. Supportive care, including hydration and symptom management, may be necessary for severe cases. In some instances, corticosteroids are used to reduce inflammation.

Prognosis and Follow-Up

Prognosis is generally favorable with appropriate treatment, though outcomes depend on the severity of infection and host immune response. Follow-up may include monitoring for resolution of symptoms and repeat testing if necessary. Chronic infections or complications may require extended care.

Complications

• Severe abdominal pain or intestinal obstruction.
• Malnutrition or weight loss from chronic diarrhea.
• Eosinophilic organ damage in rare cases.
• Allergic reactions to parasite antigens.

Lifestyle & Prevention

• Avoid consuming raw or undercooked snails, slugs, or other intermediate hosts.
• Thoroughly wash produce, especially from endemic regions.
• Practice good hygiene, including handwashing after handling soil or potential contaminants.
• Cook food thoroughly to kill parasites.
• Avoid exposure to contaminated water sources in endemic areas.

When to Seek Professional Help

Seek medical attention if you experience persistent abdominal pain, diarrhea, or other gastrointestinal symptoms after potential exposure to the parasite. Prompt evaluation is important for early diagnosis and treatment.

Tips for Medical Coders

When coding for intestinal angiostrongyliasis (B81.3), ensure documentation supports the diagnosis, including clinical findings, exposure history, and diagnostic test results. Verify that the code is used for intestinal involvement specifically, as other forms of angiostrongyliasis (e.g., neuroangiostrongyliasis) are coded separately. Follow guidelines for reporting parasitic infections and associated complications.