Hantavirus Outbreak Tracker 2026 — Live Cases, Map & Updates

Frequently asked questions about hantavirus 2026

What is hantavirus?

Hantavirus (genus Orthohantavirus) is a family of rodent-borne RNA viruses that cause two distinct syndromes in humans: Hantavirus Pulmonary Syndrome (HPS) in the Americas, and Haemorrhagic Fever with Renal Syndrome (HFRS) across Eurasia. The virus is carried by specific rodent reservoir species and shed in their urine, faeces, and saliva. Humans become infected by inhaling aerosolised particles from dried rodent excreta — typically in enclosed or poorly ventilated spaces where rodents have been active.

Can hantavirus spread from person to person?

With one exception, hantaviruses do not transmit between people. The exception is Andes virus (ANDV), endemic to southern South America, which has documented person-to-person transmission in rare cases involving very close and prolonged contact — typically household members providing care to a severely ill patient. The 2026 MV Hondius cluster is caused by Andes virus. All other hantaviruses, including Sin Nombre virus (North America) and Puumala virus (Europe), are rodent-to-human only.

What are the symptoms of hantavirus?

Symptoms begin 1 to 8 weeks after exposure. The prodromal phase lasts 3 to 5 days with fever, severe myalgia (muscle pain), headache, dizziness, and sometimes gastrointestinal symptoms. In HPS this is followed by rapid onset of shortness of breath as the lungs fill with fluid (non-cardiogenic pulmonary oedema) — this cardiopulmonary phase can progress to respiratory failure within 24 hours. HFRS presents with haemorrhage, hypotension, and acute kidney injury. There is no licensed antiviral and no vaccine outside South Korea.

What is the hantavirus death rate (case fatality rate)?

Case fatality rates vary sharply by serotype. Sin Nombre virus (SNV, North America) carries approximately 36–38% CFR per CDC surveillance. Andes virus (ANDV, South America) is similar at 25–35%. Hantaan virus (HTNV, east Asia) causes severe HFRS with 5–15% CFR. Puumala virus (PUUV, Europe) is much milder at under 1%. Seoul virus (SEOV, worldwide via rats) is under 1%. The MV Hondius 2026 cluster, caused by Andes virus, had 3 deaths among 8 confirmed cases as of May 2026 — a case fatality rate of approximately 37%.

What is the MV Hondius hantavirus outbreak in 2026?

The MV Hondius is a Dutch expedition cruise ship operated by Oceanwide Expeditions. In April 2026 it sailed from Ushuaia, Argentina, carrying passengers who had undertaken a wildlife excursion in Tierra del Fuego — an Andes virus endemic area. Cases of Hantavirus Pulmonary Syndrome were confirmed among passengers of multiple nationalities. By May 2026, WHO Disease Outbreak News DON600/DON601 reported 8 confirmed cases and 3 deaths across at least 6 countries. This is the first documented hantavirus outbreak linked to international travel on a cruise vessel.

Which countries have hantavirus cases in 2026?

The 2026 MV Hondius cluster has confirmed or suspected cases in passengers from Argentina, the United Kingdom, France, Germany, the Netherlands, and South Africa, among others. Endemic transmission continues year-round in the United States (Sin Nombre virus, particularly in the Four Corners region and western states), Chile and Argentina (Andes virus), Finland, Sweden and Germany (Puumala virus), and China and South Korea (Hantaan and Seoul virus). HORIZON tracks reports from 57 countries.

Where is hantavirus found in the United States?

Sin Nombre virus (SNV) is the primary hantavirus in the US, carried by the deer mouse (Peromyscus maniculatus). It is endemic across the western United States, with the highest case rates in New Mexico, Colorado, Arizona, Utah, Montana, and the Four Corners region. Bayou virus (Louisiana), Black Creek Canal virus (Florida), and New York virus (northeastern US) are additional North American serotypes but cause far fewer cases. The CDC has recorded approximately 850 HPS cases in the US since 1993, with a case fatality rate around 36%.

How is hantavirus transmitted?

The primary route is inhalation of aerosolised rodent excreta — dried urine, faeces, or saliva that become airborne when disturbed. This most often occurs when cleaning rodent-infested spaces without respiratory protection. Direct contact with infected rodents (bites, handling) is a secondary route. Ingestion of contaminated food or water is possible but uncommon. For Andes virus only, person-to-person spread via respiratory droplets or very close contact with a severely ill patient has been documented.

Is there a vaccine or treatment for hantavirus?

There is no licensed antiviral treatment for HPS. Care is supportive: oxygen therapy, mechanical ventilation, fluid management, vasopressors, and ECMO in severe cases. Ribavirin has shown some benefit in early HFRS but not in HPS. South Korea has licensed Hantavax, a killed Hantaan virus vaccine, but it is not available elsewhere and does not protect against Andes or Sin Nombre virus. As of May 2026, multiple research programmes are investigating mRNA-based hantavirus vaccines but none have reached Phase 3 trials.

How long is the hantavirus incubation period?

The incubation period for hantavirus is typically 1 to 8 weeks, with an average of 2 to 4 weeks. This is important for the MV Hondius outbreak: passengers who were on the ship in April 2026 may not develop symptoms until May or even June 2026. Public health authorities in affected countries issued guidance that exposed passengers should monitor for symptoms for up to 45 days after their last potential exposure.

What is Andes virus (ANDV)?

Andes virus is an orthohantavirus endemic to southern South America, particularly Chile and Argentina. It is carried by the long-tailed pygmy rice rat (Oligoryzomys longicaudatus). It causes Hantavirus Pulmonary Syndrome with a case fatality rate of approximately 25–35%. It is the only hantavirus with confirmed person-to-person transmission. The 2026 MV Hondius outbreak strain was confirmed as Andes virus by laboratory analysis in South Africa and Switzerland. HORIZON tracks all Andes virus reports in its ANDV serotype cluster.

How does HORIZON track hantavirus?

HORIZON aggregates signal from 66+ live sources including WHO Disease Outbreak News, CDC Health Alert Network, ECDC Communicable Disease Threats Reports, PAHO alerts, Eurosurveillance, Journal of Virology, mBio, PubMed, bioRxiv, ProMED, Reuters, AP, BBC, AFP, and national public health agencies across 40+ countries. Every record is rated on the NATO Admiralty Scale (reliability A–F, credibility 1–6) and assigned a dual pipeline/analyst confidence score. The open dataset is available under CC BY 4.0 via the HORIZON API.