Emergency: If you suspect hantavirus exposure, seek immediate medical attention. For more information, visitCDC.gov
HantavirusInfo

About Hantavirus

Comprehensive medical information about hantavirus infections, how they occur, what they feel like, and how healthcare providers diagnose and manage them.

Hantavirus Pulmonary Syndrome (HPS)

Hantavirus Pulmonary Syndrome (HPS) is a severe, sometimes fatal respiratory disease caused by infection with hantaviruses. It was first recognized in 1993 during an outbreak in the Four Corners region of the United States.

The Sin Nombre virus ("virus with no name" in Spanish) is the predominant hantavirus strain in North America. Deer mice serve as the primary reservoir and shed the virus throughout their lifetimes without becoming ill themselves.

HPS primarily affects the lungs, causing them to fill with fluid — a condition called pulmonary edema. This can cause breathing to become extremely difficult and lead to respiratory failure within hours in severe cases.

Key Facts
First identified1993 — Four Corners region
Primary US strainSin Nombre virus
Primary reservoirDeer mouse (P. maniculatus)
Case fatality rate~36% (US, historical)
Annual US cases~20–40 confirmed
Highest risk statesColorado, New Mexico, California, Texas

Symptom Timeline

Incubation Period
1–8 weeks after exposure
Severity: None
  • No symptoms present
  • Virus replicating in body
  • Person is not contagious
Early (Prodromal) Phase
Days 1–5 of illness
Severity: Moderate
  • Fever (101–104°F / 38.3–40°C)
  • Fatigue and malaise
  • Muscle aches (myalgia), especially hips, thighs, back
  • Headache
  • Dizziness
  • Chills
  • Nausea, vomiting, diarrhea (sometimes)
Cardiopulmonary Phase
Days 5–10 (onset 4–10 days after fever)
Severity: Critical
  • Cough (initially dry, may become productive)
  • Shortness of breath (dyspnea)
  • Rapid breathing (tachypnea)
  • Fluid accumulation in lungs (pulmonary edema)
  • Falling blood pressure
  • Heart rhythm irregularities
  • Shock may develop
Recovery Phase
Days 10–30+ (survivors)
Severity: Improving
  • Rapid improvement in lung function
  • Breathing normalizes
  • Fatigue may persist weeks to months
  • No long-term lung damage in most survivors
Critical: The transition from the prodromal to cardiopulmonary phase can happen very quickly — sometimes within hours. Anyone with risk factors and early symptoms should seek hospital care before breathing difficulty develops.

Diagnosis & Treatment

Laboratory Diagnosis

Diagnosis is confirmed through serology (IgM/IgG antibodies), PCR testing on blood, or immunohistochemistry on tissue. Early HPS can look like influenza — mention rodent exposure to your doctor. Chest X-rays reveal characteristic bilateral infiltrates in the lungs.

Supportive Treatment

There is no specific antiviral treatment for HPS. Patients require intensive care including supplemental oxygen, mechanical ventilation, and careful fluid management. ECMO (extracorporeal membrane oxygenation) has been used in severe cases to support heart and lung function.

Early Intervention Matters

Patients who are hospitalized early — before respiratory failure — have significantly better outcomes. Ribavirin has been studied but has not shown clear benefit in clinical trials. Research into specific antivirals continues at CDC and NIH.

Frequently Asked Questions

Medical Sources & References
CDC — Hantavirus Pulmonary Syndrome (HPS)
NIH — National Institute of Allergy and Infectious Diseases
WHO — Hantavirus disease fact sheet
MMWR — Hantavirus Surveillance, United States
New England Journal of Medicine — HPS clinical reviews
American Journal of Tropical Medicine