Andes virus: the hantavirus at the center of the 2026 cruise outbreak

Andes virus is the hantavirus most often named in coverage of the May 2026 cruise ship cluster. It is a member of the hantavirus family — but it is not the same strain as the hantaviruses that cause most cases of Hantavirus Pulmonary Syndrome (HPS) in the United States, and the differences are the part that gets lost in headlines. This page restates what public-health agencies publish, in plain language, so you can read the news without guessing which “hantavirus” is being discussed.

For the broader U.S. baseline, see Hantavirus in the United States and Transmission. For the current news context, see Cruise ship outbreak: what U.S. readers should know and Could the cruise ship hantavirus outbreak cause a pandemic?.

In one paragraph

Hantaviruses are a family. Different strains live in different rodent reservoirs in different parts of the world, and the illnesses they cause cluster into two broad clinical patterns: HPS (lung-focused) and HFRS (kidney-focused). In the United States, most HPS is associated with Sin Nombre virus carried by deer mice, and the CDC notes that person-to-person spread is not typical for the strains commonly seen in U.S. cases. Andes virus is a different strain, native to southern South America (Argentina and Chile), and is the one strain where investigators have documented person-to-person transmission in specific outbreak settings. It is the strain at the center of the 2026 cruise cluster.

Where Andes virus comes from

According to public-health agency materials, Andes virus is endemic to parts of Argentina and Chile, where its rodent reservoir is the long-tailed pygmy rice rat (Oligoryzomys longicaudatus). Human infections in the region have historically been tied to rural and peri-rural exposures — agricultural settings, woodpiles, and rodent-infested cabins — through the same exposure pathways as other hantaviruses: inhaled aerosols of contaminated rodent urine, droppings, or nesting material; direct contact with contaminated surfaces; and, rarely, rodent bites.

What makes Andes notable in the scientific literature is that, in specific outbreak settings, it has been linked to person-to-person transmission — most often involving close, prolonged contact with severely ill patients (household members, caregivers, healthcare workers in some early reports). The CDC’s clinician materials describe this as an exception in the hantavirus family, not the rule for the strains driving most U.S. cases.

How Andes differs from U.S. HPS-causing strains

These distinctions matter because they shape what “hantavirus” means for a given headline.

Reservoir. U.S. HPS is dominated by Sin Nombre virus carried by deer mice in rural and peri-rural settings. Andes virus is carried by a different South American rodent species in different ecological zones.
Geography. Sin Nombre cases concentrate in the western and central U.S. Andes cases concentrate in southern Argentina and Chile. Cases outside those regions usually trace back to travel-related exposure rather than local transmission.
Person-to-person spread. For Sin Nombre and the other strains commonly in U.S. surveillance, CDC framing is that person-to-person spread is not how cases are typically acquired. For Andes virus, person-to-person transmission has been documented in specific outbreak contexts, particularly close-contact settings with severely ill patients. The two should not be flattened into a single “hantaviruses spread between people” claim, and they should not be flattened into a single “they don’t” claim either.
Clinical pattern. Both Sin Nombre and Andes cause HPS — a severe lung-focused illness. The general clinical features the CDC describes for HPS (early flu-like prodrome, then cardiopulmonary phase) are broadly similar. See Symptoms and HPS incubation and symptom timeline.

For the kidney-focused hantavirus illness pattern (HFRS) — including the Seoul virus that the CDC notes is found worldwide, including in the United States — see HFRS and Seoul virus.

Why person-to-person spread is a careful claim, not a flat yes/no

Hantavirus reporting often collapses into one of two failure modes: “hantavirus doesn’t spread between people” or “hantavirus can spread between people.” Both are wrong as universal statements, and both miss the part that actually matters for a reader.

The CDC’s clinician materials describe person-to-person transmission of hantaviruses as a phenomenon documented in specific outbreak settings with Andes virus, not as a routine property of hantaviruses generally. Subsequent investigations have refined the picture: the highest-risk situations involve close, prolonged contact with severely ill patients, not casual community exposure. That is epidemiologically very different from a respiratory virus that propagates through commuter trains and offices.

So when news coverage of the 2026 cluster references person-to-person transmission, the careful reading is: yes, for this specific strain, in specific high-contact settings, transmission to close contacts has been documented in the past — and that is part of why public-health authorities take Andes-virus outbreak investigations seriously. It does not mean a passing-stranger exposure model. For a longer treatment, see Can hantavirus spread person to person?.

What this means for U.S. readers right now

If you live in the United States and have no recent travel to affected areas, the everyday hantavirus risk you actually control still runs through rodent exposure and unsafe cleanup, not through casual person-to-person contact. That is the part of the picture an individual can act on:

Read Rodent droppings cleanup for the dust-aware (“wet”) method the CDC describes.
Read Seasonal cabins, storage, and RVs before opening a closed building or stored vehicle this spring.
Read Prevention for the CDC’s Seal Up, Trap Up, Clean Up framing.

If you have recent travel history to an area where Andes virus is endemic — or contact with someone in the 2026 cluster who has been contacted by a public-health authority — that authority’s instructions take precedence over anything this page can offer. If you develop fever, muscle aches, or worsening shortness of breath after a plausible exposure, contact a clinician and mention the exposure history — see Symptoms, HPS incubation and symptom timeline, and Diagnosis and testing.

Common search questions, briefly

Is Andes virus a new virus? No. Andes virus has been recognized in the medical literature for decades and is the dominant HPS-causing strain in parts of southern South America. What is new is the cruise-ship cluster, not the virus itself.

Is there a vaccine for Andes virus? Vaccine work for hantaviruses (including Andes) has been ongoing for years and remains in development. There is no licensed public option at the time of review. For the difference between “scientists are working on a vaccine” and “you can get a vaccine,” see Is there a hantavirus vaccine?.

Is Andes virus the same as the “next COVID”? Public-health agencies have not framed Andes virus as a pandemic-grade respiratory pathogen. The careful version of that question is on Could the cruise ship hantavirus outbreak cause a pandemic?.

Can my pet catch Andes virus? The CDC’s general hantavirus guidance treats household pets as not the main vector of concern; rodent control around the home is the higher-leverage prevention focus. See FAQ and Prevention.

How is Andes virus treated? There is no specific antiviral therapy licensed for hantavirus in the United States; CDC describes care as supportive, with severe HPS often requiring intensive care. See Treatment and recovery.

Related guides

Cruise ship outbreak: what U.S. readers should know — the May 2026 cluster in interpretation, not breaking news.
Can hantavirus spread person to person? — U.S. baseline vs. Andes nuance, in depth.
Hantavirus in the United States — deer mice, Sin Nombre virus, where U.S. risk actually concentrates.
HFRS and Seoul virus — the kidney-focused hantavirus pattern and a strain the CDC notes is found worldwide.
Could the cruise ship hantavirus outbreak cause a pandemic? — what WHO and ECDC actually say.
Is there a hantavirus vaccine? — candidate vs. in-trials vs. licensed.
Symptoms and HPS incubation and symptom timeline — what to watch for after a possible exposure.
Prevention and Rodent droppings cleanup — the part of the picture you control day-to-day.