Hantavirus

  • Diagnosis
  • Background
  • Lab Tests
  • References
  • Related Content

Indications for Testing

  • Consider diagnosis in thrombocytopenic patients with febrile illness and applicable rodent exposure

Criteria for Diagnosis

Laboratory Testing

  • Initial testing
    • Early in syndrome, diagnosis is usually clinical, but confirmation requires serum testing
    • CBC – in cardiopulmonary phase
      • Peripheral smear demonstrates thrombocytopenia – associated with prolonged tachypnea
      • Myelocytosis – >10% lymphocytes with immunoblastic morphology
    • Liver function tests – commonly elevated
    • PT/PTT – prolonged PTT is most common
  • Serologies using ELISA testing – confirm diagnosis
    • IgM appears relatively early after infection and declines over several weeks
      • Indicates recent exposure
    • IgG generally appears later and may remain elevated for years
  • PCR
    • Not widely available
    • Only useful in early stages when patient is viremic

Histology

  • Immunohistochemical staining (if available) is sensitive

Imaging Studies

  • Chest x-ray
    • Interstitial infiltrates most common
    • Pulmonary edema evident in more severe cases

Differential Diagnosis

Hantavirus causes hantavirus cardiopulmonary syndrome (HPS) (first reported in the Americas) and hemorrhagic fever with renal syndrome (HFRS) in Asia and Europe.

Epidemiology

  • Incidence – <50 cases annually in U.S.
  • Sex – M>F
  • Transmission – inhalation of infected aerosols from rodents

Organism

  • Hantavirus is the only member of the Bunyaviridae family not arthropod-transmitted
    • At least 11 species associated with human disease
  • Enveloped virus with tri-segmented, negative-stranded RNA
  • At least 25 genotypes identified in Americas
  • Virus is hosted by rodents of family Cricetidae

Clinical Presentation

  • Incubation of 1-2 weeks – fever, myalgia, headache, chills, abdominal pain, nonproductive cough, gastrointestinal symptoms
  • HPS – rapid development of dyspnea and pulmonary edema; diffuse infiltrates on chest x-ray
    • If hospitalization does not occur, hypotension and shock may follow, resulting in death within 3-6 days
  • Prolonged tachypnea; tachycardia common

Indications for Laboratory Testing

Tests generally appear in the order most useful for common clinical situations.
Click on number for test-specific information in the ARUP Laboratory Test Directory

Partial Thromboplastin Time 0030235
Method: Electromagnetic Mechanical Clot Detection

Hantavirus Antibodies, IgG and IgM with Reflex to Confirmation 2001540
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay

Limitations

False positives occur in cytomegalovirus, influenza and Mycoplasma pneumoniae infection

Follow Up

If test results are equivocal, repeat testing in 10-14 days

Additional Tests Available

CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential

Comments

Assist in ruling out bacterial infection

Hepatic Function Panel 0020416
Method: Quantitative Enzymatic/Quantitative Spectrophotometry

Comments

Evaluate for hepatitis

Prothrombin Time 0030215
Method: Electromagnetic Mechanical Clot Detection

Comments

Initial testing to rule out coagulopathy

General References

Hartline J, Mierek C, Knutson T, Kang C. Hantavirus infection in North America: a clinical review. Am J Emerg Med. 2013; 31(6): 978-82. PubMed

Klein S, Calisher C. Emergence and persistence of hantaviruses. Curr Top Microbiol Immunol. 2007; 315: 217-52. PubMed

Mattar S, Guzmán C, Figueiredo L. Diagnosis of hantavirus infection in humans. Expert Rev Anti Infect Ther. 2015; 13(8): 939-46. PubMed

Mertz G, Hjelle B, Crowley M, Iwamoto G, Tomicic V, Vial P. Diagnosis and treatment of new world hantavirus infections. Curr Opin Infect Dis. 2006; 19(5): 437-42. PubMed

Mir M. Hantaviruses. Clin Lab Med. 2010; 30(1): 67-91. PubMed

Simpson S, Spikes L, Patel S, Faruqi I. Hantavirus pulmonary syndrome. Infect Dis Clin North Am. 2010; 24(1): 159-73. PubMed

Medical Reviewers

Last Update: January 2016