CLINICAL GUIDE · UPDATED MAY 7, 2026

Andes Virus Symptoms:
What to Watch For

Andes virus causes hantavirus pulmonary syndrome (HPS) — a severe respiratory illness with approximately 40% case fatality rate. Symptoms progress through distinct phases. Early detection and ICU admission significantly improves survival. There is no approved vaccine or antiviral treatment.

⚠ EMERGENCY SIGNS — CALL 911 IMMEDIATELY

If you were potentially exposed to Andes virus and develop sudden shortness of breath, go to an emergency room immediately. Tell the treating team about potential Andes virus exposure. Time is critical during the cardiopulmonary phase.

SYMPTOM PROGRESSION BY PHASE

Days 1–5 · PRODROMAL PHASE

Early symptoms resemble severe flu. Many patients and clinicians initially misdiagnose this phase.

  • Fever (38–40°C / 100–104°F)
  • Severe headache
  • Muscle pain, especially lower back and thighs
  • Chills and sweating
  • Nausea, vomiting, diarrhea
  • Fatigue, general malaise
Days 5–10 · CARDIOPULMONARY PHASE

This is the critical and often fatal phase. Respiratory failure can develop within hours.

  • Sudden shortness of breath (hallmark symptom)
  • Rapid heart rate (tachycardia)
  • Fluid accumulation in lungs (pulmonary edema)
  • Low blood pressure
  • Oxygen saturation drops rapidly
  • Cyanosis (bluish skin) in severe cases

EMERGENCY: If shortness of breath develops after fever, call emergency services immediately. This phase can become life-threatening within 4–6 hours.

Days 10+ · DIURETIC/RECOVERY PHASE

Survivors who make it past the cardiopulmonary phase typically begin to improve. ICU care is usually required.

  • Gradual improvement in breathing
  • Fluid clearance from lungs
  • Weeks to months of recovery
  • Mechanical ventilation may be required before improvement
  • Approximately 40% fatality rate — survivors recover fully
  • No vaccine or antiviral exists

HOW ANDES VIRUS SYMPTOMS DIFFER FROM FLU

SYMPTOM
ANDES VIRUS
INFLUENZA
Sudden shortness of breath
✓ Key feature
✗ Rare
Severe muscle pain
✓ Prominent
✓ Common
Respiratory failure
✓ Common (40% fatal)
✗ Uncommon
Runny nose / sore throat
✗ Uncommon
✓ Common
Gradual onset
✗ Abrupt
✓ 1–4 days
ICU admission needed
✓ Often required
✗ Rarely
NEXT →
Incubation Period
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How It Spreads