B75 Trichinellosis

Name of the Condition

• Trichinellosis

Summary

Trichinellosis is a parasitic infection caused by the nematode Trichinella species. The condition typically results from consuming undercooked meat containing encysted larvae, leading to gastrointestinal and systemic manifestations. Symptoms range from mild gastrointestinal upset to severe systemic illness, depending on the parasite load and host factors.

Causes

The infection is caused by ingestion of Trichinella larvae in raw or undercooked meat, most commonly pork, wild game, or other carnivorous animals. The larvae mature in the small intestine, penetrate the intestinal wall, and migrate to striated muscle tissue, where they encyst and can persist for years.

Risk Factors

• Consumption of undercooked or raw meat from infected animals.
• Handling raw meat without proper hygiene.
• Ingestion of meat from wild game or non-inspected sources.
• Living in regions where Trichinella is endemic or where meat inspection practices are limited.

Symptoms

• Gastrointestinal symptoms (nausea, vomiting, diarrhea, abdominal pain) within 1–2 days of infection.
• Systemic symptoms (fever, muscle pain, periorbital edema, weakness) appearing 1–2 weeks later.
• Neurological symptoms (headache, dizziness, confusion) in severe cases.
• Skin manifestations (rash, subconjunctival hemorrhages) may occur.

Diagnosis

Diagnosis is based on clinical presentation, exposure history (e.g., consumption of undercooked meat), and laboratory findings. Serological tests (e.g., ELISA) detect antibodies to Trichinella. Muscle biopsy may confirm the presence of encysted larvae, though this is less commonly performed. Imaging or eosinophilia may support the diagnosis.

Treatment Options

Treatment involves anthelmintic therapy (e.g., albendazole or mebendazole) to target adult worms and migrating larvae. Corticosteroids may be used for severe systemic or neurological symptoms to reduce inflammation. Supportive care, including pain management and hydration, is often necessary.

Prognosis and Follow-Up

Prognosis is generally good with early treatment, though severe cases can lead to complications. Most patients recover fully, but residual muscle pain or fatigue may persist. Follow-up may include monitoring for recurrence of symptoms or complications, especially in immunocompromised individuals.

Complications

• Myocarditis or encephalitis in severe cases.
• Respiratory failure due to muscle involvement.
• Persistent muscle pain or weakness.
• Gastrointestinal complications (e.g., perforation) in rare instances.

Lifestyle & Prevention

• Thoroughly cook meat to an internal temperature of at least 160°F (71°C).
• Avoid consuming raw or undercooked meat, especially from wild game.
• Practice proper food handling and hygiene when preparing raw meat.
• Freeze meat at sub-zero temperatures for extended periods to kill larvae (where applicable).

When to Seek Professional Help

Seek medical attention if you experience symptoms after consuming undercooked meat, especially if accompanied by fever, muscle pain, or gastrointestinal distress. Prompt evaluation is critical for severe cases with neurological or cardiac involvement.

Tips for Medical Coders

Document the clinical findings, exposure history (e.g., undercooked meat consumption), and diagnostic results to support the B75 code. Ensure specificity regarding the stage of infection (e.g., intestinal vs. muscular) if available, as this may impact coding accuracy. Note any complications or comorbidities that require additional coding.