Where is Andes virus (ANDV) found?

Andes virus (ANDV) is the dominant hantavirus of southern South America. Its natural range follows the distribution of its reservoir host, the long-tailed pygmy rice rat (Oligoryzomys longicaudatus), across:

• Argentina — Patagonian provinces (Chubut, Río Negro, Neuquén, Santa Cruz), the Andean foothills, and northeastern provinces including Salta, Jujuy, Buenos Aires, and Entre Ríos.
• Chile — from Coquimbo region south through Aysén and Magallanes; concentrated in the Lake District (Los Lagos, La Araucanía).

Smaller secondary clusters have been described in Uruguay, Bolivia and southern Brazil, where related Oligoryzomys species circulate variant lineages of ANDV.

Andes virus is the only hantavirus with confirmed person-to-person transmission, which makes geography particularly important for outbreak response: a single ANDV-positive traveller leaving Patagonia has triggered contact-traced clusters as far away as North America.

Cases peak in the austral summer (November–April), when humans share seasonally vegetated rural environments with the reservoir rodent. Hantavirus pulmonary syndrome (HPS) caused by ANDV has a case-fatality ratio of approximately 30–40% (PAHO).