Short answer
Andes virus is a South American hantavirus associated with hantavirus pulmonary syndrome. It is the only hantavirus that official sources describe as capable of spreading person-to-person. Rodent-to-human transmission through contaminated urine, droppings, and saliva remains the primary route.
Why Andes virus is distinct
All hantaviruses can spread from infected rodents to people through contaminated urine, droppings, saliva, or nesting material. What sets Andes virus apart is that official sources — including CDC, WHO, and ECDC — describe confirmed human-to-human transmission, typically through close prolonged contact with a sick person. This capability has not been documented in other hantavirus strains. Andes virus is not known to circulate in North American rodent populations; its natural reservoir is rodents in South America.
Rodent-to-human transmission
Like other hantaviruses, Andes virus spreads from infected rodent reservoir species through inhalation of aerosolized urine or droppings, direct contact with contaminated materials, or rarely a bite. The rodent reservoir species for Andes virus are found in South American countries including Argentina and Chile. Risk from rodent-to-human transmission follows the same prevention principles as other hantaviruses: avoid disturbing rodent waste without prior wet disinfection, ventilate closed structures before entry, and use appropriate protective equipment. See hantavirus prevention for detail.
Person-to-person transmission
Official sources describe Andes virus person-to-person transmission as limited and tied to close contact. Documented transmission has occurred between household members, intimate partners, and people in enclosed shared spaces. CDC, WHO, and ECDC consistently note that this is not broad casual public spread. The Andes virus person-to-person spread page explains the contact risk categories, monitoring protocol, and infection control guidance.
Symptoms and disease
Andes virus causes hantavirus pulmonary syndrome, with the same general progression as other HPS strains. Early symptoms include fever, fatigue, muscle aches, headache, and gastrointestinal symptoms. These progress in some patients to cough, shortness of breath, and chest tightness. The critical phase involves rapid cardiopulmonary deterioration and may require mechanical ventilation and intensive care. Case fatality rates without intensive care can be high. See hantavirus symptoms and the symptoms timeline for more detail.
Incubation period
CDC states that signs and symptoms of HPS due to Andes virus appear 4 to 42 days after exposure. WHO guidance is consistent with this range. For close contacts of Andes virus cases, public-health authorities may recommend a 42-day monitoring window derived from this maximum incubation period. See hantavirus incubation period for detail.
Current outbreak relevance
The MV Hondius 2026 outbreak is linked to Andes virus and includes confirmed person-to-person transmission. See current outbreak situation and MV Hondius outbreak for current counts and official risk assessments. Official agencies including WHO, ECDC, and CDC have assessed broad public risk as low, very low, or extremely low, based on the transmission characteristics of Andes virus.
Risk assessment summary
WHO, ECDC, and CDC have each published risk assessments for this outbreak. All describe the risk to the general public as low, very low, or extremely low. People identified as high-risk contacts by public-health authorities, or healthcare workers caring for Andes virus cases, should follow official monitoring and infection-control instructions for their specific situation.
Sources reviewed for this page
Frequently asked questions
What is the incubation period for Andes virus?
CDC states that signs and symptoms of HPS due to Andes virus appear 4 to 42 days after exposure. Most cases present within several weeks. Public-health monitoring windows for high-risk contacts are typically set at 42 days to cover the full documented range.
Who should follow monitoring instructions?
People who have been identified by public-health authorities as high-risk or close contacts of a confirmed Andes virus case should follow those official instructions. High-risk contacts typically include household members, intimate partners, and people with prolonged close indoor exposure during a case's symptomatic period.
Is Andes virus found in North America?
No. Andes virus circulates in South American rodent populations, primarily in Argentina and Chile. It is not known to be carried by rodents in North America. Exposure risk for North American residents comes from travel to endemic areas or close contact with an Andes virus case — not from local rodents.
What is the fatality rate for Andes virus infection?
Case fatality rates for HPS vary by setting and access to intensive care. CDC historical data shows approximately 36 to 38 percent case fatality for HPS overall in the United States. Individual outcomes depend on how early hospital care is received and the quality of supportive treatment available.
How long is someone with Andes virus contagious?
Official sources do not specify a precise end to the contagious period. WHO guidance recommends precautionary measures for high-risk contacts for 42 days, which covers the full incubation range. Healthcare and household contacts of suspected Andes virus cases should use appropriate precautions until directed otherwise by public-health authorities.
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Report a correctionPrimary sources reviewed
CDC, WHO, and ECDC official public-health pages were reviewed for this build. Current outbreak counts use official outbreak updates; evergreen pages use official background and guidance pages.