Hantavirus

Aka: Hantavirus, Hantavirus Pulmonary Syndrome, Hantavirus Cardiopulmonary Syndrome, Hanta Virus, Andes Virus, Sin Nombre Virus, Black Creek Canal Virus, Bayou Virus, New York Virus, Four Corners Virus, Muerto Canyon Virus

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II. Epidemiology

  1. Farm settings and other rural areas
    1. Associated with entering rarely opened buildings
    2. Associated with increased rodent populations
  2. Most common in spring and summer
  3. Ages affected
    1. Mean age affected is middle aged adults
    2. Less commonly affects children
  4. United States
    1. Incidence U.S.: 890 cases since 1993 (as of 2023, cases/year: 30)
    2. First identified in 1993 in 4 corners (New Mexico, Arizona, Colorado and Utah)
    3. Now HPS has been identified in 31 states and Canada
    4. Initial cases were identified in southwest U.S.
      1. New Mexico
      2. Arizona
      3. California
  5. Worldwide
    1. North and South America (HPS clinical syndrome)
      1. In 2025, eight countries reported total of 229 cases and 59 deaths (25.7% CFR)
        1. https://www.paho.org/en/documents/epidemiological-alert-hantavirus-pulmonary-syndrome-americas-region-19-december-2025
    2. Asia and Europe (HFRS clinical syndrome)
      1. Asia (esp. East China and South Korea) experience thousands of cases per year
      2. In 2023, Europe reported 1885 cases
        1. https://www.ecdc.europa.eu/en/publications-data/hantavirus-infection-annual-epidemiological-report-2023
  6. Outbreaks
    1. Shipborne person-to-person transmission of Andes Strain with HPS in May 2026 (WHO)
      1. https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON601

III. Pathophysiology

  1. Family Hantaviridae (and the genus Orthohantavirus)
    1. First described in soldiers during Korean War in 1950s
      1. Originally termed "Hantaan Virus" as cases occurred near Hantaan River, Korea
    2. Reclassified as of 2018 (previously classified as Bunyaviridae)
    3. Enveloped, Helical single stranded RNA Viruses (70-160 nm)
    4. Hantaviridae strains identified: 24
  2. Anti-Message Sense RNA Viruses (Negative Stranded, -ssRNA)
    1. Anti-Message sense RNA (-ssRNA) need to first be transcribed into +ssRNA
    2. RNA dependent RNA Polymerase (RNA replicase, RdRp)
      1. RdRp is an enzyme carried by the -ssRNA virus within its capsid
      2. RdRp transcribes -ssRNA into +ssRNA within the host cell
    3. Translation follows +ssRNA transcription from -ssRNA (by RdRp)
      1. As with mRNA, +ssRNA translated by host ribosomes into Protein
  3. HPS Vectors (North America)
    1. Deer mouse (main vector): Sin Nombre Virus
    2. Cotton rat (Southeast U.S.): Black Creek Canal Virus
    3. Rice rat (Southeast U.S.): Bayou Virus
    4. White-footed mouse (Northeast U.S.): New York Virus
  4. Transmission
    1. Contact with the urine, faeces, or Saliva of infected rodents or by touching contaminated surfaces
      1. Inhalation of aerosolized rodent feces or Saliva is most common
      2. Highest risks for transmission include cleaning buildings with rodent infestations
    2. No identified Nosocomial Infections
    3. Person to person transmission in rare (Andes Strain only)
      1. Secondary transmission to healthcare workers is even less common (but can occur in early phase of illness)
  5. Infection
    1. Hantaviruses infect endothelial, epithelial, dendritic, and Lymphocyte cells
      1. Viral Glycoproteins attach to cell surface receptors (esp. immature dentritic cells)
    2. From skin, virus spreads to Lymphatics
      1. Replication within regional Lymph Nodes

IV. Types: Clinical Syndromes

  1. Hantavirus Cardiopulmonary Syndrome (HCPS) or Hantavirus Pulmonary Syndrome (HPS)
    1. Described on this page
    2. Strains causing HPS are limited to the Americas
      1. Primary North American strain is Sin Nombre Virus (SNV)
        1. Other strains: New York, Black Creek Canal, Bayou, Monongahela
      2. Primary South American strain is Andes Virus (ANDV)
        1. Other strains: Laguna Negra, Oran, Choclo, Rio Mamore, Lechiguanas
    3. Andes Strain (South America, esp. Argentina and Chile)
      1. Responsible for shipborne outbreak in May 2026
      2. Only strain demonstrating persion-to-person transmission
  2. Hemorrhagic fever with renal syndrome (HFRS)
    1. Strains limited to Asia and Europe (Hantaan, Dobrava, Seoul, Puumala)
    2. Associated with Acute Kidney Injury, Thrombocytopenia, fever, and Hypotension
    3. Note: HFRS is NOT covered on this page

V. Symptoms and Signs: Prodromal Phase (HPS)

  1. Follows 1 to 6 week (up to 8 week) Incubation Period after exposure
  2. Atypical cases may cause only prodromal phase
  3. Symptoms
    1. Mild febrile illness lasting 3-5 days
    2. Myalgias
    3. Gastrointestinal upset
    4. Headache
    5. Chills
    6. Malaise
  4. Signs
    1. Fever
    2. Tachypnea
    3. Tachycardia
  5. Findings rarely seen in HPS (Negative Predictive Value)
    1. Rash, Conjunctivitis (occur with South American HPS)
    2. Rhinorrhea
    3. Pharyngitis

VI. Symptoms and Signs: Cardiopulmonary Phase (HPS)

  1. Symptoms
    1. Progressive Tachypnea
    2. Cough productive of copious secretions
  2. Signs: Acute Pulmonary Edema
    1. Hypoxia
    2. Respiratory Failure within first 24 hours
    3. Cardiogenic Shock in severe cases
      1. Low Cardiac Output
      2. Hypotension
      3. High Peripheral Vascular Resistance
      4. Oliguria

VII. Labs

  1. Hypoalbuminemia (later finding)
  2. Lactic Acidosis (later finding)
  3. Liver Function Tests elevated
  4. Chemistry Panel
    1. Hyponatremia (variably present)
    2. Renal Function Tests
      1. Acute Renal Failure may occur
  5. Complete Blood Count
    1. Repeat in 8-12 hours if initial CBC normal
    2. Combination of all 4 criteria rare in other viral ID
      1. Thrombocytopenia (marker of severity)
      2. Leukocytosis with left-shift (severe Leukocytosis with DIC)
      3. Circulating immunoblasts
      4. Hemoconcentration (Hematocrit increased)
  6. Serology (in U.S.)
    1. Sin Nombre Virus IgM (ELISA assay)

VIII. Imaging: Chest XRay (HPS)

  1. Diffuse Interstitial Edema
  2. Pleural Effusions
  3. Differs from ARDS by involving more central lung

IX. Differential Diagnosis (HPS)

  1. Pneumonia
  2. ARDS
  3. Acute Bacterial Endocarditis
  4. Plague
  5. Tularemia
  6. Histoplasmosis
  7. Coccidioidomycosis
  8. Myocardial Infarction
  9. Goodpasture's Syndrome

X. Management (HPS)

  1. Early aggressive Intensive Care is associated with best outcomes
  2. Intensive cardiopulmonary support
    1. Mechanical Ventilation
    2. Vasopressors
    3. Invasive hemodynamic monitoring
    4. Careful fluid management
      1. Maintain normal to high filling pressures for Cardiac Output
      2. Avoid Pulmonary Edema (may avert Mechanical Ventilation)
  3. Initial broad spectrum Antibiotics (for other causes)
    1. Employ while awaiting SNV serologic titers
    2. Covers other causes on differential diagnosis
  4. Ribavirin (Virazole)
    1. See Viral Hemorrhagic Fever for protocol
  5. Experimental measures being investigated
    1. Extracorporeal Membrane Oxygenation (ECMO)

XI. Prognosis

  1. Mechanical Ventilation required in 40% of HPS patients
    1. Better prognosis with early improvement in first few days (and Extubation in first week)
  2. Case fatality rate: 25% (up to 40-50% in some studies)
    1. One third of patients may die in first 48 hours of admission despite Intensive Care
    2. Disseminated Intravascular Coagulation (associated Hemorrhage) is among the main causes of death
  3. Survivors may have persistent small airway obstruction
  4. Survivors often recover within 1 week of illness

XII. Prevention

  1. Eliminate rodent populations in and around buildings
  2. Avoid rodent exposure
  3. No licensed treatment or Vaccine is available for Hantavirus infection

XIII. Resources

  1. Hantavirus Pulmonary Syndrome (StatPearls)
    1. https://www.ncbi.nlm.nih.gov/books/NBK513243/

XIV. References

  1. (1996) MMWR Morb Mortal Wkly Rep 1996 45:291-5 [PubMed]
  2. Graziano (2002) Am Fam Physician 66:1015-20 [PubMed]
  3. Vitek (1996) Clin Infect Dis 22:824-6 [PubMed]

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