Lower BP thresholds may represent significant deterioration
Polypharmacy interactions
Beta-blockers may blunt tachycardia as early warning sign
Diuretics may compound hypovolemia
ECMO eligibility
Age alone not a contraindication
Comorbidity burden and functional status guide decision
Pediatrics
HPS in children
Epidemiology in pediatric population
Cases reported in patients as young as 2 years old
Pediatric HPS (1993-2018): similar mortality to adult cases
Distribution of cases mirrors adult geographic pattern
Presentation differences
GI symptoms may be more prominent
Prodrome duration similar to adults
Thrombocytopenia and immunoblasts equally characteristic
Dosing adjustments
Dobutamine: 2-20 mcg/kg/min weight-based
Norepinephrine: 0.05-2.0 mcg/kg/min weight-based
All inotropes dosed by weight
ECMO in pediatrics
Pediatric ECMO centers required
Early transfer recommended
Fluid management
Same principle of fluid restriction applies
Inotropes preferred over volume loading regardless of age
Background
Epidemiology
Global and US burden
Sin Nombre virus (SNV): primary cause in North America
Cases reported in 39 US states; western states carry highest risk
Approximately 850 cases confirmed in the US since 1993 (historical data)
Case fatality rate: approximately 35-40%
Seasonal peak: spring and summer
Rodent populations peak with vegetation abundance
Human outdoor activity increases concurrently
Environmental and geographic drivers
Reservoir: deer mice (Peromyscus maniculatus) for SNV
Drought followed by heavy rainfall increases rodent populations
Open developed areas and arid climates associated with higher risk
Peridomestic rodent infestation as major urban exposure pathway
Demographic patterns
Age >18 years and female sex identified as independent mortality prognostic factors
Rural residence associated with increased case fatality
Certain HLA haplotypes may influence disease severity
Pathophysiology
Viral entry and tropism
Transmission: inhalation of aerosolized rodent urine, feces, and saliva
No person-to-person transmission for SNV
Andes virus: documented person-to-person transmission (sexual contact, close household contact)
Viral tropism for endothelial cells of pulmonary vasculature
Immunopathogenesis
T-cell-mediated immunopathology drives capillary leak (not direct viral cytopathic effect)
Massive endothelial permeability increase leads to non-cardiogenic pulmonary edema
Concomitant myocarditis contributes to depressed systolic function
Unique hemodynamic signature: hypovolemia plus systolic dysfunction plus increased permeability
Distinct from classic cardiogenic shock and classic septic shock
Clinical phases
Incubation: 5-50 days (median 18 days)
Prodromal phase: 2-7 days of fever, myalgias, GI symptoms
Cardiopulmonary phase: 2-4 days of refractory shock and respiratory failure
Most deaths occur within first 24 hours of this phase
Convalescent phase: rapid recovery in survivors
Endothelial barrier function reverses quickly
Most survivors recover fully
Therapeutic Considerations
No specific antiviral therapy approved
Ribavirin: no survival benefit in placebo-controlled trial for HCPS
Favipiravir: efficacy in animal models when given before viremia; not approved for clinical use
Corticosteroids: no proven benefit
Management is entirely supportive
Early recognition is the single most important factor in survival
Hemodynamic management evidence
Inotrope-first strategy superior to volume-loading strategy
VA-ECMO: 80% survival in case series; strongest evidence-based intervention for severe HPS
High-volume hemofiltration: bridge or alternative to ECMO in select cases (Journal of Medical Virology 2021)
Research landscape
Convalescent plasma: lower mortality in Andes virus open study; not standard of care
Long-term sequelae not well characterized
Pulmonary function normalization may take weeks in survivors
Patient Discharge Instructions
copy discharge instructions
Discharge instructions for Hantavirus Pulmonary Syndrome
What you were diagnosed with
You were evaluated for possible hantavirus infection, a rare but serious illness spread from rodents
This infection can cause severe lung and heart problems that worsen rapidly
Medications
There is no specific antiviral medication proven to treat this infection
Take all prescribed medications as directed
Activity restrictions
Rest at home and avoid strenuous activity
Do not return to areas with known rodent exposure until fully recovered
Rodent exposure prevention
Seal all entry points in your home to prevent rodent access
Use wet cleaning methods (damp mop/wipe) in rodent-contaminated areas; do not sweep or vacuum dry droppings
Wear an N95 respirator during any cleanup in rodent-contaminated spaces
Ventilate enclosed spaces (cabins, sheds) for at least 30 minutes before entering
Return to emergency department immediately for
Any new cough or shortness of breath
Worsening difficulty breathing
Chest tightness or pressure
Feeling faint, dizzy, or lightheaded
High fever (>38.5 degrees C) that is not improving
Inability to keep fluids down
Decreased urine output
Household contacts
If you were potentially exposed to Andes virus, notify household contacts to monitor for symptoms for 40 days
Contact your local health department for guidance on exposure management
Follow-up
Follow up with your primary care physician within 1 week of discharge
Infectious disease follow-up as arranged by your hospital team
Report any new or worsening respiratory symptoms immediately
References
Guidelines and key sources
Primary references
Abdoler EA, Malani PN. What Is Hantavirus? JAMA. 2025. https://jamanetwork.com/journals/jama/fullarticle/10.1001/jama.2025.5014
Vial PA, Ferres M, Vial C, et al. Hantavirus in Humans: A Review of Clinical Aspects and Management. Lancet Infect Dis. 2023. https://pubmed.ncbi.nlm.nih.gov/37105214
Riquelme R. Hantavirus. Semin Respir Crit Care Med. 2021. https://pubmed.ncbi.nlm.nih.gov/34918323
Ulloa-Morrison R, Pavez N, Parra E, et al. Critical Care Management of Hantavirus Cardiopulmonary Syndrome. J Crit Care. 2024. https://pubmed.ncbi.nlm.nih.gov/39024823
Epidemiology and natural history
Duchin JS, Koster FT, Peters CJ, et al. Hantavirus Pulmonary Syndrome: A Clinical Description of 17 Patients. NEJM. 1994. https://www.nejm.org/doi/full/10.1056/NEJM199404073301401
Watson DC, Sargianou M, Papa A, et al. Epidemiology of Hantavirus Infections in Humans. Crit Rev Microbiol. 2014. https://pubmed.ncbi.nlm.nih.gov/23607444
Hartline J, Mierek C, Knutson T, Kang C. Hantavirus Infection in North America: A Clinical Review. Am J Emerg Med. 2013. https://pubmed.ncbi.nlm.nih.gov/23680331
Graziano KL, Tempest B. Hantavirus Pulmonary Syndrome: A Zebra Worth Knowing. Am Fam Physician. 2002. https://pubmed.ncbi.nlm.nih.gov/12358213
ECMO and advanced therapy
Crowley MR, Katz RW, Kessler R, et al. Successful Treatment of Adults With Severe HPS With ECMO. Crit Care Med. 1998. https://pubmed.ncbi.nlm.nih.gov/9468181
Lopez R, Perez-Araos R, Salazar A, et al. Targeted high volume hemofiltration in severe HCPS. J Med Virol. 2021. https://onlinelibrary.wiley.com/doi/10.1002/jmv.26930
Special populations and prognostic factors
Tortosa F, Ragusa MA, Neumann I, et al. Prognostic Factors for Mortality in New World Hantaviruses. BMJ Open. 2026. https://pubmed.ncbi.nlm.nih.gov/41592833
Thorp L, Fullerton L, Whitesell A, Dehority W. Hantavirus Pulmonary Syndrome 1993-2018. Pediatrics. 2023. https://pubmed.ncbi.nlm.nih.gov/36855865
Martinez VP, Di Paola N, Alonso DO, et al. Super-Spreaders and Person-to-Person Transmission of Andes Virus. NEJM. 2020. https://www.nejm.org/doi/full/10.1056/NEJMoa2009040
Gorris ME, Whitesell A, Telford C, Shoemaker T, Bartlow AW. Hantavirus Associated With Open Developed Areas and Arid Climates. Transbound Emerg Dis. 2025. https://pubmed.ncbi.nlm.nih.gov/41141578
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.