Andes Virus (ANDV): What Makes It Different From Other Hantaviruses
The strain confirmed in the 2026 MV Hondius cruise ship outbreak is uniquely dangerous: it can spread person-to-person.
Person-to-Person
Andes virus is the ONLY hantavirus that can spread between humans
Up to 50% CFR
Case fatality rate in the Americas — among the highest of any respiratory virus
South America Origin
Endemic to Argentina, Chile, and neighbouring countries. Rodent reservoir: long-tailed pygmy rice rat
How Does Andes Virus Spread?
Primary Route — Rodent Contact:
Like all hantaviruses, Andes virus is primarily spread through contact with infected rodent droppings, urine, or saliva. Inhaling aerosolized particles (e.g., while cleaning a contaminated area) is the most common infection route.
Secondary Route — Person to Person (UNIQUE TO ANDES VIRUS):
Andes virus is the only hantavirus confirmed to spread from person to person. This requires:
- ✓ Prolonged close contact (not brief or casual)
- ✓ Exposure to body fluids: saliva, respiratory droplets
- ✓ Contact during the early prodromal phase (before severe symptoms appear)
- ✗ NOT airborne like measles or COVID-19
- ✗ NOT spread through brief elevator contact or passing someone in a store
💬 CDC (May 2026): "Andes virus is the only type of hantavirus that is known to spread person-to-person. This spread is usually limited to people who have close contact with a sick person, including direct physical contact, prolonged time spent in close or enclosed spaces, and exposure to the sick person's body fluids."
Andes Virus vs. Other Hantaviruses
| Feature | Andes Virus (ANDV) | Sin Nombre Virus (US) | HFRS Strains (Asia/EU) |
|---|---|---|---|
| Region | South America | North America | Asia, Europe |
| P2P Transmission | ✅ YES | ❌ No | ❌ No |
| Primary Organ | Lungs (HPS) | Lungs (HPS) | Kidneys (HFRS) |
| CFR | Up to 50% | ~35% | <1–15% |
| Vaccine | ❌ None | ❌ None | ✅ China (HFRS only) |
| 2026 Outbreak | ✅ MV Hondius | — | — |
Incubation Period
After exposure to Andes virus:
- • Minimum: 7 days
- • Median: 18 days ← Watch this window closely
- • Maximum: up to 39–40 days
MV Hondius context: If you were exposed on April 1 (departure), you could develop symptoms as late as mid-May 2026.
Learn more about incubation periods →Andes Virus Symptoms
Phase 1 — Prodromal (Days 1–5):
- • Fever (38–40°C / 100–104°F)
- • Severe fatigue
- • Muscle aches (thighs, hips, back)
- • Headache, chills
- • Nausea, vomiting, diarrhea
- • Abdominal pain
⚠️ WARNING: This phase is when person-to-person transmission is most likely. Infected individuals may not yet know they have Andes virus.
Phase 2 — Cardiopulmonary (Days 5–10):
- • Rapid heart rate
- • Shortness of breath
- • Low blood pressure
- • Cough (dry)
- • Lungs filling with fluid (pulmonary edema)
Phase 3 — Critical / Recovery:
- • Pulmonary edema progresses
- • Respiratory failure risk
- • Shock — ICU required
- • OR: gradual recovery (if caught early and treated in ICU)
History of Andes Virus Outbreaks
1995: Andes virus first identified in Chile and Argentina
1996: First confirmed person-to-person transmission documented in Argentina
2014: Cluster of 3 P2P cases in Argentina confirmed by full-genome sequencing
2026: Largest international Andes virus cluster — MV Hondius cruise ship, 8 cases, 3 deaths, 23 nationalities, CFR 38%