NIH
Zebra of the week: Hantavirus pulmonary syndrome (HPS)
Overview
Hantavirus pulmonary syndrome (HPS) is a rare but highly lethal zoonotic infection caused by New World hantaviruses (family Hantaviridae), most commonly the Sin Nombre virus in North America. It is characterized by a rapidly progressive cardiopulmonary illness with capillary leak, pulmonary edema, and shock. Although uncommon, HPS carries a case fatality rate of ~35–40%, making early recognition critical.
Transmission & Epidemiology
HPS is primarily acquired through inhalation of aerosolized viral particles from rodent excreta (urine, feces, saliva), particularly in enclosed or poorly ventilated spaces. Direct contact, bites, or contaminated food are less common routes. Exposure risk is highest in rural or rodent-infested environments. Human-to-human transmission is generally not seen with North American strains, but has been reported with the Andes virus in South America.
Clinical Presentation
After an incubation period of 1–8 weeks, illness typically begins with a viral prodrome (3–5 days):
- Fever, fatigue, myalgia (especially thighs/hips/back)
- Headache, chills
- GI symptoms (nausea, vomiting, abdominal pain)
This rapidly progresses to the cardiopulmonary phase, marked by:
- Noncardiogenic pulmonary edema → dyspnea, cough
- Hypoxia, tachycardia
- Hypotension and shock
Radiographically and clinically, this phase mimics ARDS. Laboratory findings may include thrombocytopenia and hemoconcentration.
Diagnosis
Diagnosis relies on:
- Clinical suspicion + rodent exposure history
- Serology (IgM/IgG) or PCR confirmation
Early disease is often misdiagnosed as influenza, COVID-19, or atypical pneumonia, delaying recognition.
Management
There is no specific antiviral therapy for HPS. Treatment is supportive and should occur in an ICU setting:
- Careful fluid management (avoid worsening pulmonary edema)
- Early oxygen supplementation
- Mechanical ventilation for respiratory failure
- Consider ECMO in refractory hypoxemia
Early aggressive supportive care improves survival.
Clinical Pearl
Think of HPS in patients with rapid respiratory decompensation following a flu-like illness plus rodent exposure—especially when thrombocytopenia and hemoconcentration are present.
Recent Clinical Context: 2026 Atlantic Cruise Outbreak
A recent multinational outbreak aboard a trans-Atlantic expedition cruise ship (MV Hondius) underscores the relevance of this rare diagnosis. As of early May 2026, 7–9 confirmed or suspected cases and 3 deaths were reported among ~150 travelers prompting an international public health response.
The outbreak is notable for suspected involvement of the Andes virus, the only hantavirus known to allow person-to-person transmission under close contact conditions. This remains atypical, as most HPS cases are sporadic and linked to environmental exposure rather than clusters.
For clinicians, this cluster highlights:
- The importance of travel and exposure histor
- The potential (albeit rare) for clustered cases
- The need to consider hantavirus in severe, unexplained ARDS presentations—even outside classic rural settings
Public health authorities emphasize that the overall risk to the general population remains low, but vigilance is warranted.
Sources:
NIH GARD. Hantavirus Pulmonary Syndrome
CDC. Hantavirus Pulmonary Syndrome (HPS): Clinical Overview for Healthcare Providers
StatPearls. Hantavirus Pulmonary Syndrome. NCBI Bookshelf
Mayo Clinic. Hantavirus Pulmonary Syndrome: Diagnosis & Treatment
WHO. Disease Outbreak News: Hantavirus Cluster Linked to Cruise Ship Travel (May 2026)
CBS News / Associated Press. Hantavirus Cases Linked to Cruise Ship Outbreak (May 2026)