Hantavirus in the United States — What You Need to Know Right Now

Whether you just saw a news alert or you’ve been following this story all week, these are the eight most important questions people are asking about hantavirus right now — with straight answers drawn directly from CDC, WHO, NIH, and peer-reviewed research. The most important message: this is a serious but rare disease, and the risk to people going about their normal lives in the United States is genuinely low.

• 1
  What is hantavirus, and is it new? Not new — tracked in the US since 1993 · Caused by viruses carried by rodents · Different strains exist in different parts of the world · The Andes strain in the cruise ship outbreak originated in South America · The most common US strain is Sin Nombre virus, carried by deer mice in the West and Southwest

  Hantaviruses are a family of viruses that live primarily in rodents — deer mice, cotton rats, rice rats, and others depending on the region — and can be transmitted to humans through contact with infected rodent droppings, urine, saliva, or nesting material. They are not a new discovery. American physicians first identified hantavirus pulmonary syndrome (HPS) in the United States during a 1993 outbreak in the Four Corners region of the Southwest, where Arizona, Utah, Colorado, and New Mexico converge. Since surveillance began that year, the CDC has tracked just over 900 confirmed cases in the US through early 2025, making it genuinely rare by any standard. In the US, the dominant strain is Sin Nombre virus, spread by deer mice. The strain driving the current cruise ship outbreak — Andes virus — is found in South America and is the only known hantavirus strain capable of spreading from person to person, even though that transmission remains uncommon and requires close, prolonged contact. There are no Andes virus-carrying rodents found in the United States.
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  Is hantavirus contagious — can it spread from person to person? Almost never — the vast majority of hantavirus strains, including the US strain, do NOT spread person to person · The single exception is the Andes strain (South America), which can spread between people through close, prolonged contact — and this is what’s involved in the cruise ship outbreak · It is not airborne like influenza or COVID — normal daily contact does not spread it

  This is the question that separates the cruise ship outbreak from ordinary hantavirus concerns. The CDC is explicit: of all known hantaviruses, only the Andes virus has documented evidence of human-to-human transmission. Even for Andes virus, that transmission requires close and prolonged personal contact — the type associated with household members or intimate partners caring for someone who is actively ill. Casual contact (sitting near someone, shaking hands, sharing an elevator) has not been shown to transmit Andes virus. It does not spread through the air the way influenza or COVID-19 do. The Sin Nombre virus — the strain responsible for all domestic US hantavirus cases — cannot spread person to person at all. You cannot get it from another person. You can only get it from direct exposure to infected rodent waste or materials. Health officials on the MV Hondius are operating under the assumption that limited person-to-person spread of Andes virus may have occurred among passengers who had close, repeated contact with ill individuals aboard the ship. But for people who were never on the ship, the only realistic path to Andes virus infection would be travel to South American regions where the carrier rodent lives.
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  What are the symptoms of hantavirus? Early (days 1–5): Fever, fatigue, muscle aches, headache, nausea, vomiting, dizziness — easily mistaken for flu or stomach virus · Late (days 4–10): Sudden severe shortness of breath, fluid building in the lungs, rapid drop in blood pressure — can progress to respiratory failure within hours · Incubation: 1 to 8 weeks after exposure before any symptoms appear · Key warning: If you had rodent exposure or cruise ship exposure and develop any of these — seek care immediately

  Hantavirus pulmonary syndrome (HPS) — the form caused by both Sin Nombre virus in the US and Andes virus in the cruise ship outbreak — moves through two distinct phases that can make early diagnosis difficult. The first phase looks and feels like a routine flu or stomach bug: sudden fever, muscle aches (especially in the large muscles of the thighs, hips, and back), deep fatigue, headache, and often nausea, vomiting, or diarrhea. There is typically no cough, runny nose, or sore throat, which can help distinguish HPS from a cold. What makes HPS uniquely dangerous is what happens next: within a few days of those initial symptoms, the lungs begin filling with fluid. This can happen rapidly — sometimes within hours. Breathing becomes increasingly difficult, oxygen levels drop, and blood pressure falls. Patients can deteriorate from feeling moderately unwell to requiring intensive care extremely quickly. The critical lesson from the CDC and infectious disease experts is this: the window between first symptoms and serious respiratory failure is short, and outcomes are significantly better for patients who receive intensive medical care early. If you have any reason to believe you may have been exposed — whether through rodent contact at home or connection to the cruise ship — and you develop any fever or muscle aches, do not wait to see if it gets better. Call your doctor or go to an emergency room and tell them about the possible exposure.
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  What is the death rate for hantavirus? High compared to most viruses — approximately 1 in 3 people who develop full HPS respiratory symptoms in the US do not survive · Andes virus (the cruise ship strain) carries an estimated 35–50% mortality · Early hospital care with ECMO (a machine that takes over heart and lung function) can reduce mortality significantly · No specific antiviral treatment or vaccine currently exists

  Hantavirus is not common, but when it causes full-blown hantavirus pulmonary syndrome, it is genuinely dangerous. The University of Arizona’s Cooperative Extension, drawing on CDC data, reports that approximately one in three Americans who develop HPS with respiratory symptoms die from the disease. That tracks with the CDC’s own historical figures, which put the US case fatality rate at around 36%. The Andes virus involved in the cruise ship outbreak carries a higher estimated mortality — the UK Health Security Agency cites approximately 35 to 50 percent, and earlier published research puts the figure around 40 percent. However, access to modern intensive care changes this picture considerably. Research from the University of Florida College of Medicine notes that ECMO — extracorporeal membrane oxygenation, a machine that temporarily takes over heart and lung function — can reduce mortality in Andes virus patients from roughly 50 percent down to around 20 percent. The challenge is that ECMO requires a specialized hospital facility and must be deployed before the patient deteriorates past a certain threshold. There is currently no FDA-approved antiviral drug specifically for hantavirus, and no vaccine exists for use in the United States. Treatment is entirely supportive — managing oxygen, fluids, blood pressure, and cardiac function while the body fights the infection. This is why early hospital admission is so critical.
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  Is there a treatment or vaccine for hantavirus? No FDA-approved antiviral treatment exists for hantavirus · No vaccine is currently available in the United States · Treatment is supportive care — managing breathing, oxygen, blood pressure, and fluids · ECMO (heart-lung bypass machine) at specialized hospitals is the most effective intervention for severe cases · Ribavirin (an antiviral) has shown some benefit in early studies but is not standard treatment

  The absence of an approved antiviral drug or vaccine is one of the most frustrating aspects of hantavirus. The CDC’s dedicated Andes virus guidance page confirms that there is no specific antiviral treatment or vaccine currently available. This has been the case since hantavirus was first described in the US in 1993. What hospitals can do — and where outcomes genuinely improve — is aggressive supportive care. This means mechanical ventilation when breathing becomes compromised, careful fluid management to prevent worsening of lung edema, vasopressors to maintain blood pressure, and dialysis if kidney function deteriorates. For the most severe cases of HPS and hantavirus cardiopulmonary syndrome (HCPS), ECMO — which routes blood outside the body through a machine to oxygenate it before returning it — provides the heart and lungs a chance to rest and recover. Research published by the University of Florida suggests this intervention has meaningfully lowered mortality in severe cases. Ribavirin, a broad-spectrum antiviral, has been studied for hantavirus and showed some early promise in animal models and case reports, but clinical trial data have not established it as a standard of care. Vaccine development is an active area of research globally — particularly given the increasing attention on hantaviruses — but nothing has cleared clinical trials for US use. The bottom line from infectious disease experts: get to a hospital early, before respiratory failure takes hold, and seek a facility with critical care and ECMO capability if possible.
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  Which US states have hantavirus? Where is the risk highest at home? Western and Southwestern states carry the highest domestic risk · Highest historical case counts: New Mexico (119), Colorado (119), Arizona (85+), California (78+), Washington (59+) · The Four Corners region (AZ, CO, NM, UT) is the recognized epicenter · Deer mice carrying Sin Nombre virus are found throughout rural and semi-rural areas of the West · Eastern US cases are rare but have occurred

  Domestically — separate from the cruise ship situation entirely — hantavirus is an ongoing, low-level public health concern concentrated in the western United States. The University of Arizona’s Cooperative Extension, drawing on CDC surveillance data, confirms that since tracking began in 1993 through 2022, the CDC recorded 864 cases nationally. Colorado and New Mexico each lead with approximately 119 cases, followed by Arizona with 85, California with roughly 78, and Washington with around 59. From 2023 through 2024 alone, an additional 60-plus cases were reported in Arizona, Colorado, New Mexico, Washington, and California — suggesting the virus remains an active presence, not a historical footnote. In 2025, hantavirus gained renewed national attention when Betsy Arakawa, wife of the late actor Gene Hackman, died of hantavirus pulmonary syndrome at their home in Santa Fe, New Mexico — a stark reminder that this risk exists in ordinary residential settings, not just remote wilderness. The carrier in all US domestic cases is the deer mouse (Peromyscus species), a small rodent found throughout rural and semi-rural areas of the West. Risk rises when people enter spaces where deer mice have been nesting — cabins that have been closed for winter, storage sheds, attics, crawl spaces, or garages with mouse activity. Disturbing dried mouse droppings or nesting material without protection aerosolizes the virus. Residents in the Southwest, Rocky Mountain states, and Pacific states should be alert to deer mouse activity on their properties, particularly after seasons with heavy rainfall that drive rodent population increases.
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  Is hantavirus going to become a pandemic like COVID-19? No — experts are in strong agreement on this · Hantavirus (including Andes) spreads very differently from COVID: it requires direct rodent contact or very close prolonged contact with an actively ill person · It does not spread through brief casual contact or respiratory droplets the way COVID did · WHO and CDC both state the current cruise ship outbreak poses LOW risk to the general public · No evidence of widespread community transmission anywhere

  The comparison to COVID-19 has spread rapidly online, but infectious disease specialists are consistent and clear in pushing back on it. Multiple experts consulted by major news outlets in May 2026 — including Today.com’s medical team — emphasized that hantavirus and the virus that caused COVID-19 are fundamentally different in their transmission biology. COVID-19 spreads efficiently through respiratory droplets and aerosols with brief contact between people in shared spaces. Hantavirus does not work this way. Even the Andes strain — the most transmissible of all hantaviruses — requires close, prolonged exposure to an infected person, primarily during the period when they are actively symptomatic. There is no documented chain of community spread from Andes virus that resembles what COVID-19 did. The WHO Director General stated on May 7, 2026 that while the cruise ship outbreak is a serious incident, the WHO assesses the public health risk as low and does not anticipate a large epidemic. The CDC echoed this assessment. The biological barriers that make hantavirus dangerous (severity, mortality rate) are very different from the barriers that allow a virus to spread at pandemic scale (efficient transmission, long infectious period before symptoms, ability to spread through casual contact). Hantavirus has none of those pandemic-enabling characteristics. The right response is careful surveillance, contact tracing for those actually connected to the cruise ship, and the standard rodent-hygiene precautions that apply year-round in endemic US areas — not broad social alarm.
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  How do you protect yourself from hantavirus at home? Never sweep or vacuum dry rodent droppings — this sends the virus airborne · Before cleaning mouse-infested areas: ventilate the space for 30+ minutes, wear rubber gloves and an N95 mask, spray droppings with bleach solution and let sit 5 minutes before wiping · Seal gaps in your home (mice fit through a hole the size of a dime) · Use snap traps indoors rather than poison · Keep firewood, brush piles, and clutter away from your home’s foundation

  The single most important thing to know about preventing domestic hantavirus infection is this: never dry-sweep, vacuum, or blow air over mouse droppings in an enclosed space. This is how the overwhelming majority of US hantavirus infections occur — a person enters a cabin, shed, or room that has been sealed for months with an active deer mouse infestation, starts cleaning without protection, and inhales aerosolized virus from disturbed droppings or nesting material. The CDC’s prevention protocol, reinforced by the University of Arizona Cooperative Extension’s 2025 guidance, calls for a specific approach when cleaning rodent-contaminated spaces: first, open all windows and doors and leave the area for at least 30 minutes to allow fresh air to displace potentially contaminated air. Then, wearing rubber or latex gloves and a properly fitted N95 respirator (not a cloth or surgical mask), spray the droppings, nest materials, and surrounding surfaces thoroughly with a bleach-water solution (1.5 cups of bleach per gallon of water) and allow it to soak for at least five minutes before wiping up with paper towels. Dispose of materials in sealed plastic bags. Wash hands thoroughly after removing gloves. For ongoing prevention at home: seal any openings larger than a quarter-inch in your home’s foundation, walls, and around pipe entries (mice can enter gaps the size of a dime). Use snap traps rather than rodenticide poison for indoor control — poison causes mice to die inside walls and may pose secondary risks. Keep woodpiles, debris, and dense vegetation at least 100 feet from your home’s foundation, as these provide nesting habitat and shelter for deer mice. If you live in the Southwest or Western mountain states and notice heavy mouse activity — especially after an unusually wet spring — be particularly careful before entering any structure that has been closed since fall.

Use the buttons below to locate urgent care clinics, emergency rooms, state health departments, and pest control services in your area. If you have symptoms and a known exposure, go directly to an emergency room — do not use urgent care for potential hantavirus.