Hantavirus is back in the news after a May 2026 outbreak linked to the MV Hondius, a Dutch expedition cruise ship that departed from Ushuaia, Argentina.
Key takeaways
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In its Disease Outbreak News update, the World Health Organization (WHO) reported an initial cluster of seven suspected or confirmed cases, including three deaths, with illness marked by these symptoms:
- Gastrointestinal symptoms
- Fever
- Rapid progression to pneumonia
- Acute respiratory distress syndrome
- Shock
Associated Press reporting later noted that testing identified the Andes virus, a South American hantavirus strain that can spread between people in rare circumstances involving close, prolonged contact.
For nurses and other healthcare professionals, the key message is not to panic. Public health officials have emphasized that this isn’t a scenario similar to COVID-19 because hantavirus doesn’t spread efficiently between people.
The clinical concern is different. Hantavirus is uncommon, easy to miss early, and potentially severe once cardiopulmonary symptoms begin. Axios explained why the current outbreak differs from COVID-19, while National Geographic explained why a cruise-associated hantavirus outbreak is rare.
What is hantavirus?
Hantaviruses are a family of viruses carried by rodents like mice, according to the Centers for Disease Control and Prevention (CDC). They can cause serious illness in humans, most notably hantavirus pulmonary syndrome (HPS) and hemorrhagic fever with renal syndrome (HFRS).
HPS is more commonly associated with hantaviruses in the Western Hemisphere, including the U.S., while HFRS is more commonly associated with hantaviruses found in Europe and Asia. Seoul virus, which can cause HFRS, is found worldwide, including in the U.S.
In the U.S., the most common hantavirus associated with HPS is spread by the deer mouse. HPS primarily affects the lungs and can cause a rapid transition from nonspecific viral symptoms to severe respiratory compromise. The CDC notes in its Clinician Brief that HPS can be fatal in nearly 40% of those who are infected.
For nurses who want a broader refresher on animal-to-human transmission, Nurse.com’s course Animals Can Make You Sick: Zoonoses reviews zoonotic diseases, modes of transmission, clinical presentation, prevention, and treatment considerations.
How hantavirus spreads
Most hantavirus infections occur when people inhale tiny airborne particles contaminated with urine, droppings, saliva, or nesting material from infected rodents. This can happen when rodent-contaminated material is disturbed, such as during sweeping, cleaning, farming, opening a closed cabin or shed, or working in barns, storage spaces, campsites, or rodent-infested buildings. Infection can also occur when contaminated material enters cuts in the skin, or the eyes, nose, or mouth, and rodent bites or scratches are possible but rare transmission routes.
Most hantaviruses don’t spread from person to person. The major exception is the Andes virus, found in South America, which has been associated with limited person-to-person spread during close and prolonged contact.
The WHO has also noted that rare secondary infections among healthcare professionals have been documented previously in some healthcare settings, reinforcing the need for consistent infection prevention and control practices when the Andes virus or another South American hantavirus is possible.
A brief history of hantavirus
Hantavirus history is often traced to hemorrhagic fever with renal syndrome, including Korean hemorrhagic fever, recognized among troops during the Korean War era. Hantaan virus, named for the Hantan River region in South Korea, was identified as an etiologic agent of HFRS in 1978. Research from the National Library of Medicine summarizes the global distribution, rodent reservoirs, and clinical syndromes associated with hantaviruses.
In the U.S., hantavirus gained major attention in 1993, when an unknown and severe respiratory illness developed in the Four Corners region, where Arizona, Colorado, New Mexico, and Utah connect. A team of clinicians, epidemiologists, laboratory scientists, and public health officials identified a newly recognized hantavirus, later named the Sin Nombre virus, and connected it to the deer mouse.
The outbreak also underscored the importance of culturally appropriate public health communication, as Navajo and Hopi communities experienced stigma during early media coverage. The Emerging Infectious Diseases journal reviewed the outbreak in the publication, Hantavirus Pulmonary Syndrome — The 25th Anniversary of the Four Corners Outbreak.
CDC surveillance for hantavirus disease began during that 1993 outbreak, and HPS became nationally notifiable in 1995. As of late 2023, the CDC reported 890 laboratory-confirmed hantavirus disease cases in the U.S. since surveillance began, with 94% occurring west of the Mississippi River, and 35% resulting in death.
How long does hantavirus last in humans?
For patients, the most clinically useful timeline is the incubation and illness course. HPS symptoms usually begin one to eight weeks after exposure to an infected rodent. Early symptoms can resemble influenza and include fatigue, fever, and muscle aches, especially in areas like the thighs, hips, back, and shoulders. Headache, dizziness, chills, nausea, vomiting, diarrhea, and abdominal pain may also occur.
The late phase can begin four to 10 days after the initial symptoms. At that point, patients may develop cough, shortness of breath, and chest tightness as the lungs fill with fluid. Once the cardiopulmonary phase starts, deterioration can be rapid. According to the CDC, without adequate treatment, most deaths in patients with HPS occur within 24 to 48 hours after the onset of the cardiopulmonary phase.
Survivors may improve quickly during convalescence, but recovery can still take time, and patients may require intensive respiratory and hemodynamic support during the acute phase.
Symptoms nurses should recognize
Early hantavirus symptoms are nonspecific, which is why exposure history matters. Nurses should pay close attention when a patient has a viral prodrome plus a history of rodent exposure, rural travel, recent cleaning of enclosed spaces, occupational exposure, camping, farming, or travel to an area with known hantavirus activity.
According to the American Lung Association, early HPS symptoms can include fever, body aches, headache, dry cough, and gastrointestinal symptoms. Later findings may include shortness of breath, chest tightness, hypoxia, pulmonary edema, hypotension, acute respiratory distress syndrome, and shock.
HFRS may present more prominently with fever, intense headache, back or abdominal pain, nausea, blurred vision, hypotension, bleeding, vascular leakage, and acute kidney failure.
Clinical red flags include rapid decline after a flu-like illness, new dyspnea after a prodrome, unexplained pulmonary edema, hypotension, thrombocytopenia, hemoconcentration, leukocytosis with immunoblasts, and a credible exposure history.
Why hantavirus is relevant today
The 2026 cruise ship outbreak highlights several realities nurses may encounter:
- Patients travel internationally.
- Symptoms can begin weeks after exposure.
- Rare pathogens can appear far from their original exposure site.
The WHO advised active symptom monitoring in the context of the outbreak, and AP reported that health authorities across multiple countries were conducting contact tracing of passengers who had disembarked before the outbreak was recognized.
The outbreak is also notable because the Andes virus strain was implicated. Unlike most hantaviruses, the Andes virus can spread between people in limited situations involving close, prolonged contact.
That matters for nurses who are:
- Taking travel histories
- Assessing household or intimate contacts
- Caring for symptomatic travelers
- Coordinating with infection prevention teams and public health agencies
Hantavirus is still rare, but ecological and environmental factors can influence rodent populations and human exposure. The 1993 Four Corners outbreak followed a significant increase in the deer mouse population after an El Niño winter created more vegetation, shelter, and food for rodents. That history remains relevant because it shows how environmental conditions can change exposure risk.
What nurses and healthcare providers need to know
When hantavirus is on the differential, nurses should think in three domains:
- Exposure
- Acuity
- Communication
First, ask targeted exposure questions. Recent contact with rodent droppings, urine, nesting materials, dead rodents, contaminated food, cabins, sheds, barns, crawl spaces, campsites, farms, storage areas, or poorly ventilated enclosed spaces can be clinically important. Travel history matters, especially travel to regions where the Andes virus is present or to locations connected with a known outbreak.
Second, escalate early. The CDC advises clinicians to test for hantavirus when patients have compatible symptoms and rodent exposure, and to contact their health department at the state, tribal, local, or territorial level when symptoms and exposure history raise concern. The CDC can assist with diagnostic consultation and testing through its Viral Special Pathogens Branch.
Third, support rapid clinical management. There is no explicit treatment for a hantavirus infection. If HPS is suspected, individuals should seek emergency medical care immediately, preferably in an ICU, even before diagnosis, according to CDC guidance.
Management may include monitoring and adjustment of cardiac function, careful fluid administration, supplemental oxygen, intubation, mechanical ventilation, antipyretics, analgesics, broad-spectrum antibiotics while bacterial causes remain possible, and consideration of extracorporeal membrane oxygenation in severe decompensation.
Testing, reporting, and infection prevention
The CDC uses enzyme-linked immunosorbent assay testing to detect IgM antibodies for acute hantavirus infection. Reportable laboratory criteria can include IgM positivity, rising IgG titers, immunohistochemistry positivity, or polymerase chain reaction positivity.
Hantavirus disease is nationally notifiable, and healthcare providers, hospitals, or laboratories may be required to report cases to local health departments depending on jurisdiction.
For infection prevention, standard precautions apply to all patients. The WHO advises standard precautions plus transmission-based precautions for suspected or confirmed cases, with airborne precautions for aerosol-generating procedures.
In the context of the 2026 outbreak, the WHO also emphasized hand hygiene, avoiding dry sweeping, ventilation, self-isolation for symptomatic people, respiratory etiquette, and medical mask use when respiratory symptoms are present.
Prevention guidance nurses can share
The best prevention strategy is reducing exposure to rodents and their urine, droppings, saliva, and nesting materials. The CDC’s hantavirus prevention guidance recommends rodent control, sealing holes and gaps, trapping rodents, removing food sources, and safely cleaning contaminated areas.
People shouldn’t sweep or vacuum rodent droppings because that can aerosolize virus-contaminated particles. Wet-cleaning, disinfecting, ventilation, and appropriate protective gear are safer approaches.
Patient education should be practical and reassuring. Most people will never be exposed to hantavirus, and most strains are not spread person-to-person. But patients should seek medical care promptly if they develop fever, severe muscle aches, gastrointestinal symptoms, cough, shortness of breath, or chest tightness after rodent exposure or after close contact with a suspected Andes virus case.
FAQs about hantavirus
Is hantavirus contagious?
Most hantaviruses aren’t spread from person to person. The Andes virus is the key exception and has been associated with limited spread during close, prolonged contact.
What are the first symptoms of hantavirus?
Early symptoms often include fatigue, fever, muscle aches, headache, dizziness, chills, nausea, vomiting, diarrhea, and abdominal pain. Because these symptoms can look like influenza or other viral illnesses, exposure history is essential.
How soon do symptoms appear after exposure?
HPS symptoms usually appear one to eight weeks after contact with infected rodents. Late symptoms, including cough and shortness of breath, can appear four to10 days after the initial phase of illness.
What is the most important nursing action when hantavirus is suspected?
Recognize the exposure plus symptom pattern, escalate quickly, implement appropriate infection prevention precautions, and coordinate testing and reporting through the provider, infection prevention team, and public health department. Early intensive supportive care can improve survival.
How can patients prevent hantavirus?
Patients can reduce risk by avoiding contact with rodents and rodent-contaminated materials, sealing entry points, controlling infestations, storing food securely, ventilating enclosed spaces before cleaning, wet-cleaning contaminated areas, and avoiding sweeping or vacuuming rodent droppings.
