Hantavirus Pulmonary Syndrome

Hantavirus pulmonary syndrome (HPS), or hantavirus cardiopulmonary syndrome, is caused by New World hantaviruses (Sin Nombre virus in North America, Andes virus in South America).

• Reservoirs: deer mouse (Peromyscus maniculatus) and other rodents. Transmission through inhaled aerosolised rodent excreta; person-to-person spread occurs with Andes virus.
• About 30 cases per year in the United States; case fatality 35 to 40%.
• Risk factors: cleaning enclosed spaces (cabins, sheds, barns) with rodent infestation.

• Prodrome (3 to 5 days): fever, myalgia, headache, nausea, vomiting, and diarrhoea.
• Cardiopulmonary phase: sudden cough, dyspnoea, hypoxaemia, and non-cardiogenic pulmonary oedema with cardiogenic shock (low cardiac output, high systemic vascular resistance), often within hours.
• Laboratory: thrombocytopenia, haemoconcentration, leucocytosis with left shift and immunoblasts, raised LDH and lactate.
• Death usually within 24 to 48 hours of hospitalisation if untreated; survivors recover in days.

• Serology (IgM and IgG ELISA), RT-PCR on blood, and immunohistochemistry on tissues.
• Chest X-ray: interstitial then alveolar infiltrates, effusions.
• Echocardiography and haemodynamic monitoring show reduced cardiac index.
• Exclude influenza, severe pneumonia, ARDS from other causes, leptospirosis, sepsis, and plague.
• Notify public health authorities.

• Early recognition and transfer to ICU with extracorporeal membrane oxygenation (ECMO) capability for refractory shock and hypoxaemia.
• Cautious fluid resuscitation (avoid overload; capillary leak), early vasopressor and inotrope support, mechanical ventilation with lung protective settings (tidal volume 6 mL/kg).
• ECMO (venoarterial) improves survival in severe cardiogenic shock.
• No proven antiviral therapy; ribavirin has not shown benefit.
• Supportive: correction of acidosis, renal replacement, and management of arrhythmia.
• Prevention: rodent control, sealing homes, ventilating and wet cleaning before disturbing rodent contaminated areas, and PPE with respirators.