Hantavirus: Frequently Asked Questions

Not from any hantavirus found in the United States. CDC's clinician brief states it directly: 'the hantaviruses that are found throughout the United States are not known to spread between people.' The single worldwide exception is Andes virus in Argentina and Chile, first demonstrated molecularly in a 1996 cluster in El Bolsón (Padula et al., Virology, 1998). Even there, transmission needs close and prolonged contact — in the 2018–19 Epuyén outbreak, 34 confirmed infections traced back to one rodent-to-human introduction and were driven by three symptomatic people attending crowded social gatherings; the reproductive number fell from 2.12 to 0.96 once isolation and quarantine were enforced (Martínez et al., New England Journal of Medicine, 2020). The 2026 MV Hondius outbreak infected 13 of 147 people over weeks aboard a ship and produced no secondary case among 653 contacts traced in 33 countries after they disembarked.

CDC gives 1 to 8 weeks for HPS, and 4 to 42 days specifically for Andes virus. For HFRS it gives 1 to 2 weeks, rarely as long as 8. Because the window is wide, pinpointing the exposure event is often impossible — which is why CDC treats any rodent contact in the preceding 8 weeks as clinically relevant history. The width of that window also shaped the 2026 cruise-ship response: WHO held contacts under 42 days of monitoring and noted that, given an incubation period of up to six weeks, it was 'not unexpected that cases continue to be reported until the end of the six weeks since last exposure.' CDC: About Hantavirus

There is no FDA-approved antiviral specific to hantavirus, and the two drugs tested formally in HPS both failed: intravenous ribavirin in a placebo-controlled trial stopped for futility (Mertz et al., Clinical Infectious Diseases, 2004) and high-dose methylprednisolone in a randomised Chilean trial (Vial et al., Clinical Infectious Diseases, 2013). Treatment is supportive — maintaining oxygenation and blood pressure while the body clears the virus. For HFRS, the kidney form, intravenous ribavirin genuinely works: a 242-patient double-blind trial in China found a sevenfold reduction in the risk of death when it was started early (Huggins et al., Journal of Infectious Diseases, 1991), which is why CDC recommends it there and not for HPS. For the most severe HPS patients, 60.5% survived on ECMO in a 38-patient series (Dietl et al., 2008) and 66.6% in its 51-patient extension (Wernly et al., 2011), all with a predicted mortality of 100%.

It depends entirely on which hantavirus and which denominator. For hantavirus pulmonary syndrome in the U.S., CDC's figure is that 38% of people who develop respiratory symptoms die; across all 890 laboratory-confirmed U.S. cases from 1993 to 2023 — including 31 that never involved the lungs — CDC reports 35%, and our arithmetic on CDC's case file gives 309 ÷ 890 = 34.7%. In South America, PAHO recorded 229 cases and 59 deaths across eight countries in 2025, a regional rate of 25.7%, ranging from 0% in Panama to 55% in Brazil. For the hemorrhagic form, CDC gives 5–15% for Hantaan and Dobrava and under 1% for Puumala and Seoul — the whole EU/EEA reported three deaths among 1,885 infections in 2023 (ECDC).

Mostly no, with one documented exception that is worth knowing about. Nearly all risk comes from wild rodents — deer mice, cotton rats, white-footed mice and rice rats. But in 2017 CDC traced Seoul virus through 31 pet-rat breeding facilities in 11 states, six of which had exchanged rats with Canadian ratteries; of 183 people tested across both countries, 24 (13.1%) had antibodies, three were hospitalised and none died (Kerins et al., CDC's MMWR, 2018). CDC's standing advice is that pet rodents are not recommended for households with children under five, pregnant women, or people with weakened immune systems, and that owners can ask a veterinarian about testing new rats before introducing them to others.

Not in the United States or Europe, and not for any virus that causes disease in the Americas. Inactivated whole-virus vaccines against Hantaan or Seoul virus are licensed for human use in the Republic of Korea and in China, and published reviews credit them with reducing HFRS incidence there while stating plainly that their protective efficacy is uncertain and the immune correlates of protection are unknown (Liu et al., Frontiers in Microbiology, 2020; Chai et al., Vaccines, 2025). In the U.S., DNA vaccine candidates have completed Phase 1 and Phase 2 immunogenicity studies — an Andes virus vaccine (NCT03682107, n=48) and a Hantaan/Puumala combination (NCT04333459, n=132) — and none has progressed further. With roughly thirty U.S. cases a year, an efficacy trial cannot accumulate enough events to measure protection.

The primary carrier of Sin Nombre virus in the U.S. is the deer mouse (Peromyscus maniculatus), found across most of North America. Other carriers include the cotton rat (Sigmodon hispidus) in the Southeast (Black Creek Canal virus), the white-footed mouse (Peromyscus leucopus) in the East (New York virus), and the rice rat (Oryzomys palustris) in the Southeast. Brown and black rats can carry Seoul virus globally.

The CDC's rodent cleanup guidance advises against sweeping or vacuuming, which aerosolizes virus particles. The CDC-recommended protocol calls for ventilating the space for at least 30 minutes, wearing rubber gloves and an N95 respirator, spraying all affected material with a 10% bleach solution and letting it soak for 5–10 minutes, wiping up with paper towels and sealing in a bag, and disinfecting the area before removing PPE. CDC cleanup protocol

Yes in one sense, no in the other. CDC: when fresh rodent urine, droppings or nesting materials are stirred up, 'the virus can get into the air' and can be inhaled — that is how nearly every U.S. case happens. But it does not spread between people in the U.S. at all, and even for Andes virus, the one strain that does, WHO concluded after the 2026 cruise-ship outbreak that the virus 'did not exhibit transmission dynamics consistent with highly transmissible airborne pathogens (such as measles).' WHO's healthcare guidance reserves airborne precautions for aerosol-generating procedures and assesses the risk of healthcare-associated transmission as very low when standard measures are applied.

Cumulatively from 1993 through 2023, from our tabulation of CDC's patient-level case file: New Mexico 129, Colorado 121, Arizona 92, California 79, Washington 61, Texas 49, Utah 48, Montana 46, Nevada 39, Oregon 27, Idaho 25. Forty-one jurisdictions have recorded at least one case, and CDC reports that 94% of all cases occurred west of the Mississippi River. Provisionally in 2025, NNDSS recorded 38 HPS cases with New Mexico (7), Arizona (6) and California (6) leading and 24 of the 38 in CDC's Mountain census division.

Rare, and rarer than most headlines imply. Through the end of 2023, CDC recorded 890 laboratory-confirmed cases of hantavirus disease since surveillance began in 1993 — 859 HPS and 31 non-pulmonary infections, the latter reportable only since 2015. CDC's own surveillance analysis put annual incidence at 0.04 to 0.19 cases per million people, with yearly counts ranging from 11 to 48 (MacNeil et al., Emerging Infectious Diseases, 2011). CDC's consumer page stops at 2023, but its weekly NNDSS tables do not: they show 20 provisional HPS cases in 2024, 38 in 2025, and 10 through week 35 of 2026 (week ending September 5). Those provisional counts are routinely revised upward — 2022's year-end figure of 4 became 11 a year later — so treat any current-year number as a floor. CDC: Reported Cases of Hantavirus Disease

Dogs and cats do not become infected with hantavirus and cannot spread it directly to people. However, they may bring infected rodents or carcasses into homes, and they can pick up contaminated material on their fur. In high-risk areas, discourage pets from hunting rodents and inspect them before they re-enter the home.

No study has measured this for Sin Nombre virus, the strain behind nearly all U.S. cases, and CDC publishes no figure. What has been measured, in two other hantaviruses: Puumala virus stayed infectious in soiled rodent bedding for 12–15 days at room temperature — and infected new animals from that bedding alone — while in cell-culture fluid it lasted 5–11 days at room temperature, up to 18 days at 4°C, and was destroyed within 24 hours at 37°C (Kallio et al., Journal of General Virology, 2006). Hantaan virus in a wet suspension at 4°C remained infectious for 96 days; drying sharply reduced but did not reliably abolish infectivity (Hardestam et al., Applied and Environmental Microbiology, 2007). The practical rule that follows: cool and damp preserves it, warmth destroys it, and a rodent-used space should be treated as contaminated however long it has been shut up. CDC's own concession to survival time is indirect — it says papers and books that cannot be wetted should sit in a rodent-free space for at least three weeks, and suggests six.

Yes. Hantavirus Pulmonary Syndrome (HPS) has a case fatality rate of approximately 38% in the United States even with modern ICU care. The cardiopulmonary phase can develop within days and cause death within 24–48 hours. HFRS caused by Hantaan virus in Asia also has significant mortality. The Puumala virus strain in Europe is generally milder. Early recognition and ICU admission are the most important survival factors.

You cannot self-diagnose hantavirus. Diagnosis requires blood testing at a specialized laboratory using PCR or IgM antibody detection, done in a hospital setting. According to CDC diagnostic guidance, potential rodent exposure in the past 8 weeks combined with compatible symptoms (fever, severe muscle aches) is what prompts clinical consideration of hantavirus testing. Detailed exposure history is the key information clinicians need to evaluate possible cases. There is no at-home test. CDC: Hantavirus

The CDC advises against sweeping or vacuuming, which aerosolizes virus particles. The CDC-recommended cleanup steps are: ventilate the area with open windows and doors for at least 30 minutes; put on rubber gloves and an N95 respirator before entering; wet all droppings thoroughly with a 10% bleach solution and let soak for 5–10 minutes; wipe up with paper towels and seal in a bag; disinfect the area; and wash hands thoroughly after removing PPE. CDC cleanup protocol

Yes, and CDC gives the exact recipe: combine 1.5 cups of household bleach in 1 gallon of water — that is 1 part bleach to 9 parts water — and make the solution fresh before use. Spray until the material is very wet and let it soak for five minutes, or as long as the product label directs. CDC's alternative is any general-purpose household product whose label carries the word 'disinfectant.' It does not endorse alcohol for this job, and there is a reason to be cautious: a laboratory study found Hantaan virus partially survived two minutes in 30% ethanol, and alcohol evaporates long before a five-minute contact time is reached on a floor. CDC: How to Clean Up After Rodents

It is possible, though the greater risk comes from disturbing dried feces, urine, or nesting material rather than the carcass itself. The CDC recommends wearing rubber or nitrile gloves when handling dead rodents, double-bagging the carcass before disposal, and washing hands thoroughly after removing gloves. CDC cleanup guidance

Yes. Children can contract hantavirus the same way adults do — by inhaling aerosolized particles from infected rodent excreta or by direct contact. Public health guidance recommends supervising children in rural endemic areas and limiting their access to rodent-infested structures such as barns and outbuildings. Children are not inherently more immunologically vulnerable to hantavirus, but may face higher exposure risk due to play behaviors.

Reinfection with the same hantavirus strain is thought to be unlikely due to immune memory from the initial infection. However, infection with one hantavirus strain does not necessarily provide cross-protection against other strains. For example, recovery from Sin Nombre virus infection may not protect against Andes virus. Confirmed reinfection cases are extremely rare.

No. Hantavirus and COVID-19 are caused by entirely different viruses (hantavirus is in the family Hantaviridae; SARS-CoV-2 is a coronavirus). They spread differently: hantavirus in North America comes from rodent excreta, not from person-to-person contact. Both can cause severe respiratory illness, but early symptoms, treatment, and prevention measures are very different.

The CDC emphasizes that detailed rodent exposure history — including timing, location, and nature of any contact in the preceding 8 weeks — is the key clinical information that prompts consideration of hantavirus testing. Providing specifics about recent activity (cleaning a cabin, working in a barn, hiking in endemic areas) helps clinicians evaluate possible cases. The CDC notes that hantavirus may not be in a clinician's initial differential; comprehensive exposure history is therefore essential. CDC: Hantavirus

Yes. RVs, camper vans, and trailers that have been stored over winter are prime rodent habitat — warm, enclosed, and often with food remnants. The CDC recommends ventilating stored vehicles for at least 30 minutes before use, inspecting for rodent signs (droppings, gnaw marks, nesting material), and cleaning any contaminated areas with a bleach solution before entry. CDC cleanup guidance

While HFRS (the European/Asian form of hantavirus) is technically a hemorrhagic fever, hantavirus is distinct from Ebola, Marburg, Lassa, and other viral hemorrhagic fevers. Key differences: hantavirus in North America is not person-to-person transmissible (Ebola is), has a different virus family, different geographic distribution, different rodent reservoirs, and different clinical manifestations. HPS (the American form) causes pulmonary disease, not the hemorrhagic features seen in Ebola.