| Transmission | Rodent aerosols; Andes virus person-to-person in close contact | Human respiratory droplets, surface contact |
| Contagious person-to-person | No (except Andes virus) | Yes — highly contagious |
| Incubation period | 1–6 weeks | 1–4 days |
| Fever | Yes — high (101–104°F) | Yes — high |
| Muscle aches | Severe, concentrated in large muscles (thighs, back) | Diffuse, whole body |
| Sore throat | Rare / absent | Very common |
| Runny nose / congestion | Rare / absent | Very common |
| GI symptoms | Present in ~50% of cases | Uncommon in adults |
| Lung involvement | Severe acute pulmonary edema (life-threatening) | Usually mild; pneumonia in high-risk patients |
| Platelet count | Low (thrombocytopenia) — key lab clue | Usually normal |
| Fatality rate | 35–40% (HPS, Sin Nombre) | <0.1% in healthy adults |
| Effective antiviral | None | Oseltamivir (Tamiflu), Baloxavir |
| Vaccine available | No (for Americas HPS) | Yes — annual vaccine |