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Hantavirus in Argentina: Andes virus, regions at risk, and recent activity
Country-specific overview of hantavirus in Argentina — Andes virus, endemic provinces, person-to-person transmission, and the 2026 cruise cluster.
Argentina has had endemic hantavirus circulation for decades, and is the country where person-to-person transmission was first formally documented for any hantavirus.
Predominant virus: Andes virus (ANDV), with several lineages including Andes Sout (the most studied, in Patagonia) and Andes Centro / Norte / Lechiguanas in central and northern provinces.
Reservoir: long-tailed pygmy rice rat (Oligoryzomys longicaudatus) in the south, with other Oligoryzomys species in central and northern regions.
Endemic provinces:
- Patagonia: Río Negro, Neuquén, Chubut, Santa Cruz, Tierra del Fuego — historical hot spot, with recurrent cases in El Bolsón, San Martín de los Andes, Esquel.
- Salta and Jujuy in the north.
- Buenos Aires province delta (Central) — driven by Lechiguanas virus.
- Misiones — sporadic clusters.
Annual cases: roughly 100-200 confirmed cases per year nationwide, with case fatality around 25-30%. The actual exposure base is much wider; symptomatic cases are a small fraction.
Person-to-person transmission:
- Argentina has documented multiple Andes virus clusters with confirmed person-to-person spread, particularly in Patagonia.
- Transmission has occurred between household contacts, in healthcare settings before precautions were established, and most recently among passengers of a 2026 cruise that originated in Ushuaia.
- The phenomenon is unique to Andes virus among all hantaviruses.
The 2026 cruise cluster:
- A multi-country WHO-reported cluster linked to the MV Hondius / Wisting / similar vessels with Patagonian itineraries.
- Cases distributed across Argentina, Spain, Italy, the UK, and the Netherlands depending on which voyage.
- Investigation by ANLIS-Malbrán, ECDC, and WHO. Source of exposure under study (rodent-contaminated cabin, shore excursion, contamination during loading).
- Public health response includes contact tracing, isolation of symptomatic cases, droplet precautions in receiving hospitals.
Reference labs and reporting:
- INEI-ANLIS Carlos G. Malbrán (Buenos Aires) — national reference lab for hantavirus.
- Provincial reference labs in Bariloche, Neuquén, and Chubut.
- Mandatory notification of suspected cases under Resolución 423/MS.
Travel guidance:
- For tourism in Patagonia, the risk for typical hotel-and-restaurant itineraries is very low.
- Higher risk: backpacking, camping, staying in long-closed mountain cabins, hiking off-trail in tall vegetation.
- Standard precautions apply: do not handle rodents, ventilate before entering closed spaces, follow wet-cleaning protocols if needed.
For an updated event feed in this country, see [hantavirus events in Argentina](/country/ar). For a deep dive on the virus itself, see [Andes virus explained](/info/andes-virus-explained).