A96.2 Lassa fever

Name of the Condition

• Lassa fever

Summary

Lassa fever is a viral hemorrhagic illness caused by the Lassa virus, a member of the arenavirus family. It is characterized by fever, multi-organ dysfunction, and potential hemorrhagic manifestations. The condition can progress rapidly, requiring prompt medical intervention to manage symptoms and complications.

Causes

Lassa fever is caused by infection with the Lassa virus, an RNA virus. Transmission typically occurs through contact with infected rodents (specifically Mastomys natalensis) or their excreta, contaminated environments, or, in some cases, human-to-human transmission via bodily fluids.

Risk Factors

• Exposure to rodent habitats or contaminated materials.
• Occupational or recreational activities involving close contact with rodents.
• Living in or traveling to regions where the Lassa virus is endemic (e.g., West Africa).
• Weakened immune systems, which may increase susceptibility to severe disease.

Symptoms

• High fever
• Muscle pain
• Headache
• Fatigue
• Gastrointestinal symptoms (nausea, vomiting, diarrhea)
• Hemorrhagic signs (bleeding gums, bruising, petechiae)
• Respiratory distress
• Neurological symptoms (confusion, seizures)

Diagnosis

Diagnosis is based on clinical presentation, exposure history, and laboratory testing. Confirmatory tests include viral isolation, PCR, or serological assays to detect the Lassa virus.

Treatment Options

Treatment focuses on supportive care, including fluid and electrolyte management, blood pressure support, and treatment of complications. Antiviral therapy (e.g., ribavirin) may be considered in severe cases, particularly when initiated early.

Prognosis and Follow-Up

Prognosis varies; severe cases can be fatal, especially without timely intervention. Survivors may experience hearing loss or other sequelae. Follow-up care includes monitoring for complications and rehabilitation as needed.

Complications

• Severe hemorrhage
• Organ failure (e.g., liver, kidney)
• Hearing loss (a common long-term effect)
• Neurological damage
• Death (in severe or untreated cases)

Lifestyle & Prevention

• Avoid contact with rodents and their excreta.
• Store food in rodent-proof containers.
• Practice good hygiene, including handwashing.
• Use protective equipment in healthcare settings to prevent human-to-human transmission.
• Avoid traveling to endemic areas if high risk, or take precautions if travel is necessary.

When to Seek Professional Help

Seek immediate medical attention if you experience symptoms of Lassa fever, especially after potential exposure (e.g., travel to endemic regions, contact with rodents). Early diagnosis and treatment improve outcomes.

Tips for Medical Coders

Document the clinical presentation, exposure history, and confirmatory test results (e.g., PCR, serology) to support the diagnosis. Ensure the code A96.2 is assigned when Lassa fever is confirmed. Note any complications or sequelae for additional coding if applicable.