Hantavirus symptoms — phase by phase
Phase 1 — Early (1-7 days)
Symptoms
- ●Fever (38-40°C)
- ●Severe muscle aches in thighs, hips, lower back, shoulders
- ●Fatigue, weakness
- ●Headache and dizziness
- ●Chills
- ●Sometimes: nausea, vomiting, abdominal pain
Typically NOT seen
- ○No runny nose
- ○No sore throat
- ○No cough yet
This phase resembles flu but has more severe muscle pain in large muscle groups, and crucially no upper respiratory symptoms. People often delay care thinking it is influenza.
Phase 2 — Late cardiopulmonary (4-10 days after onset)
Symptoms
- ●Cough
- ●Shortness of breath, rapid breathing
- ●Fluid in the lungs (pulmonary edema)
- ●Low blood pressure
- ●Sometimes: rapid heart rate, confusion
Typically NOT seen
- ○Phase 1 ends abruptly; phase 2 starts within hours
- ○Without ICU support, mortality rises sharply
This is the dangerous phase for Andes virus and Sin Nombre virus (both cause Hantavirus Pulmonary Syndrome — HPS). Hospitalization is critical: oxygen, ventilation, ECMO when needed. The MV Hondius cluster involves Andes virus.
CDC clinical red flags
Per CDC Hantavirus Signs & Symptoms, the following are described as warranting urgent medical evaluation:
Acute signs
- →Severe shortness of breath or rapidly worsening breathing
- →Chest tightness with confusion or fainting
- →Cyanosis (skin or lips turning blue/grey)
Exposure context that elevates clinical suspicion
- →Recent rodent exposure (cleaning a rodent-infested space, sleeping in an endemic-area cabin)
- →Travel to a hantavirus-endemic region (parts of South America, Four Corners USA) in the past 8 weeks
- →Known close contact with a confirmed case from the MV Hondius cluster
Why exposure history matters in diagnosis. Hantavirus is rare. CDC clinical guidance notes that physicians will typically not consider hantavirus testing without knowledge of rodent contact or travel to endemic regions, because clinical presentation overlaps with influenza and other viral illnesses.
⚠ Not medical advice. Always consult a physician for individual evaluation.