B33.4 Hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS]

Name of the Condition

• Hantavirus (cardio)-pulmonary syndrome [HPS] [HCPS]

Summary

Hantavirus (cardio)-pulmonary syndrome (HPS) is a severe respiratory illness caused by hantaviruses. It is characterized by rapid onset of respiratory distress and can progress to acute respiratory failure. The condition is rare but has a high mortality rate, particularly if not diagnosed and treated promptly.

Causes

HPS is caused by hantaviruses, which are transmitted to humans primarily through inhalation of aerosolized virus particles from the urine, droppings, or saliva of infected rodents. The virus is not spread person-to-person under normal circumstances.

Risk Factors

• Exposure to rodent-infested environments, such as cabins, barns, or rural areas.
• Activities that disturb rodent nests or droppings, like cleaning sheds or camping.
• Living in regions where hantavirus-carrying rodents are common, particularly in the Americas.

Symptoms

• Early symptoms: fever, muscle aches (especially in the thighs, hips, back, and shoulders), fatigue, and headaches.
• Later symptoms: coughing, shortness of breath, and rapid fluid accumulation in the lungs, which can lead to respiratory failure.

Diagnosis

Diagnosis is based on clinical presentation, exposure history, and laboratory confirmation. Tests may include serologic assays to detect hantavirus antibodies or PCR to identify viral RNA in blood or tissue samples.

Treatment Options

Treatment is primarily supportive, focusing on managing respiratory distress. This may include oxygen therapy, mechanical ventilation, and monitoring in an intensive care setting. No specific antiviral therapy is universally recommended.

Prognosis and Follow-Up

The prognosis depends on the severity of respiratory involvement at presentation. Early recognition and supportive care improve outcomes, but mortality rates remain significant. Survivors may require ongoing monitoring for residual lung or cardiac effects.

Complications

• Acute respiratory distress syndrome (ARDS).
• Multi-organ failure due to severe hypoxia.
• Long-term pulmonary or cardiac sequelae in some survivors.

Lifestyle & Prevention

• Avoid contact with rodents and their habitats.
• Seal homes and buildings to prevent rodent entry.
• Clean potential rodent-infested areas with disinfectants and wear masks during cleanup.
• Store food in rodent-proof containers.

When to Seek Professional Help

Seek immediate medical attention if you experience unexplained fever, muscle aches, and shortness of breath, especially after potential rodent exposure. Early intervention is critical for improving survival.

Tips for Medical Coders

Use code B33.4 for hantavirus (cardio)-pulmonary syndrome. Documentation should specify the clinical syndrome and exposure history to support the diagnosis. Ensure the code aligns with the patient's confirmed or suspected hantavirus infection and associated respiratory findings.