A98.5 Hemorrhagic fever with renal syndrome

Name of the Condition

• Hemorrhagic fever with renal syndrome (ICD-10 Code: A98.5)

Summary

Hemorrhagic fever with renal syndrome (HFRS) is a viral disease characterized by fever, bleeding tendencies, and acute kidney injury. It is transmitted to humans through contact with infected rodents or their excretions. The illness can range from mild to severe, with severe cases involving hemorrhagic manifestations, renal dysfunction, and potential shock.

Causes

HFRS is caused by hantaviruses, primarily of the Hantavirus genus. The virus is transmitted to humans through inhalation of aerosolized rodent urine, droppings, or saliva, or through direct contact with infected rodents or their habitats. Human-to-human transmission is rare but has been reported in close contact settings.

Risk Factors

• Exposure to rodent-infested environments, such as rural or agricultural areas.
• Occupational risks for farmers, forestry workers, or military personnel in endemic regions.
• Living in or visiting areas with high rodent populations, especially during seasonal outbreaks.
• Lack of protective measures during activities that may disturb rodent habitats.

Symptoms

• Sudden onset of fever, chills, and severe headache.
• Muscle and back pain, often with abdominal discomfort.
• Bleeding manifestations, including petechiae, bruising, or mucosal hemorrhage.
• Oliguria (reduced urine output) or acute kidney injury in severe cases.
• Nausea, vomiting, and blurred vision may also occur.

Diagnosis

Diagnosis is based on clinical presentation, exposure history, and laboratory testing. Serologic tests (e.g., ELISA) to detect hantavirus-specific antibodies are commonly used. PCR testing for viral RNA may be performed in early stages. Differential diagnosis includes other viral hemorrhagic fevers, leptospirosis, or acute kidney injury from other causes. Imaging or renal function tests may support clinical assessment.

Treatment Options

Treatment is primarily supportive, focusing on managing symptoms and complications. Intravenous fluids are administered to maintain hydration and blood pressure. Dialysis may be required for severe renal failure. Pain management and monitoring for bleeding or shock are critical. Antiviral therapies are not routinely recommended, but experimental treatments may be considered in severe cases.

Prognosis and Follow-Up

Prognosis varies by severity, with most patients recovering fully with appropriate care. Severe cases may result in prolonged renal dysfunction or residual symptoms. Follow-up includes monitoring renal function and blood pressure, especially in patients with significant kidney involvement. Recovery may take weeks to months, with gradual improvement in symptoms.

Complications

• Acute kidney injury, which may require dialysis.
• Hemorrhagic shock due to severe bleeding.
• Pulmonary edema or respiratory distress in severe cases.
• Long-term renal impairment or hypertension in some survivors.

Lifestyle & Prevention

• Avoid contact with rodents or their habitats; seal homes and store food in rodent-proof containers.
• Use protective gear (e.g., masks, gloves) when cleaning rodent-infested areas.
• Practice good hygiene, especially after outdoor activities in endemic regions.
• Seek prompt medical care if exposure to rodents or symptoms develop.

When to Seek Professional Help

Seek immediate medical attention if you experience sudden fever, severe headache, unexplained bleeding, or reduced urine output after potential rodent exposure. Early diagnosis and supportive care improve outcomes, especially in severe cases.

Tips for Medical Coders

Document the clinical presentation, including fever, bleeding tendencies, and renal involvement, to support the A98.5 code. Note exposure history (e.g., rodent contact) and laboratory findings (e.g., serologic or PCR results) when available. Ensure coding aligns with the specific hantavirus-related diagnosis and avoids overlap with other viral hemorrhagic fevers.