Andes virus is a New World hantavirus belonging to the genus Orthohantavirus (family Hantaviridae) and is an important cause of hantavirus pulmonary syndrome (HPS) in South America. Like other hantaviruses, it has a tri‑segmented negative‑sense RNA genome (S, M and L) encoding the nucleocapsid protein, glycoproteins Gn and Gc and RNA‑dependent RNA polymerase. The virus was first isolated in 1995 from the long‑tailed colilargo (Oligoryzomys longicaudatus) in Argentina and named after the Andes mountain range where early cases occurred.
Biology, Reservoir and Unique Features
Andes virus belongs to the Andes orthohantavirus species and is closely related to other sigmodontine rodent‑borne hantaviruses in the Americas. Its primary reservoir is the long‑tailed pygmy rice rat (Oligoryzomys longicaudatus), which ranges along the foothills of the Andes in Chile and Argentina. Rodents maintain chronic infection and shed virus in urine, faeces and saliva. Humans usually become infected by inhaling aerosolised rodent excreta. Virions are enveloped and have a helical nucleocapsid. Infection targets endothelial cells and leads to increased vascular permeability, causing fever, myalgia, cough and rapidly progressive pulmonary oedema. Case fatality rates for Andes virus–associated HPS are typically 30–40 %, similar to Sin Nombre virus. Unlike other hantaviruses, Andes virus is capable of limited person‑to‑person transmission during the prodromal phase, likely through close contact with respiratory secretions.
Outbreaks and Public Health Considerations
Since its recognition in the mid‑1990s, Andes virus has been associated with sporadic cases and clusters in southern Argentina and Chile. A major outbreak in 1996‑1997 in Patagonia involved dozens of HPS cases, some linked to person‑to‑person transmission among family members and health care workers. Additional clusters have occurred in Argentina’s Andean foothills and Chile’s Los Lagos and Los Ríos regions. In 2011 and 2018, smaller outbreaks emphasised the need for stringent infection control for suspected HPS patients. There is no approved vaccine or specific antiviral therapy. Early diagnosis and supportive care, including oxygenation and extracorporeal membrane oxygenation when indicated, improve survival. Public health recommendations focus on rodent control, avoiding disturbance of rodent habitats, and implementing isolation precautions for patients to prevent secondary transmission.
Andes virus remains a significant zoonotic threat in South America due to its high mortality and unique capacity for person‑to‑person spread. Continued surveillance of rodent reservoirs and adherence to infection control measures are critical for reducing HPS cases.
Related Terms: Sin Nombre virus, Hantaan virus, Puumala virus, Dobrava-Belgrade virus, Seoul virus