May 2026
In this VETgirl online veterinary continuing education blog, Dr. Katherine Brannick, MS, DACLAM discusses what veterinary teams need to know about the Hantavirus, Andes Virus and recent cruise ship outbreak. While risks to the public and pet rats remain low, key takeaways for veterinary teams include appropriate rodent control and safe cleanup protocols of rodent infested areas.

Hantavirus, Andes Virus, and the Cruise Ship Outbreak: A Quick Review for Veterinary Teams

By Dr. Katherine Brannick, MS, DACLAM

Hantavirus sounds like one specific disease, but the reality is more nuanced, with different viruses, hosts, clinical patterns, and even changing taxonomy across the older and newer literature. This article summarizes key sources veterinary teams can use when clients ask about the recent cruise ship outbreak, whether pets are involved, and whether this is something they should be worried about. As with any active outbreak, details may shift over time, so the CDC and WHO should be the primary sources for current case counts and public health recommendations.

One reason hantavirus literature can be confusing is that older surveillance papers and current taxonomy do not use identical naming. In the older CDC/EID literature, hantaviruses are described as rodent- and insectivore-borne negative-sense RNA viruses in the family Bunyaviridae, genus Hantavirus.1,2 Current ICTV taxonomy now places these viruses in the family Hantaviridae, which includes several genera, including Orthohantavirus several of which can infect humans and cause mild, severe, and sometimes fatal disease. For a practical veterinary audience, the key point is not the taxonomy change itself, but that older papers may say “genus Hantavirus,” while newer sources may use “family Hantaviridae” and “genus Orthohantavirus.” They are part of the same literature trail, not a contradiction.3

Clinically, the major human disease patterns discussed in these sources are hantavirus pulmonary syndrome, or HPS, in the Americas, and hemorrhagic fever with renal syndrome, or HFRS, more classically associated with viruses in Europe and Asia. In the United States, the best-known cause of HPS is Sin Nombre virus, which is associated with the deer mouse (Peromyscus maniculatus). Other U.S. hantaviruses associated with human disease include Bayou, Black Creek Canal, New York, and Monongahela viruses. Seoul virus is different because it is associated with Norway rats and HFRS, and it is the hantavirus most relevant to pet rat discussions.1,2,4

The current cruise ship outbreak is getting attention because it involves Andes virus, a hantavirus normally found in South America. CDC reports that it is responding to a deadly Andes virus outbreak among passengers and crew of a cruise ship in the Atlantic Ocean. As of May 8, 2026, WHO had reported eight cases, including six confirmed and two suspected cases, with three deaths. That is scary language, and it is appropriate for public health teams to take it seriously. But the part that needs to be communicated clearly is that CDC states the risk of a pandemic and the overall risk to the American public and travelers remains extremely low. Andes virus is unusual because it is the only hantavirus known to spread person-to-person, but CDC emphasizes that it does not spread easily like COVID-19 and that person-to-person spread is usually limited to close contact with someone who has symptoms.5,6

For historical context in the United States, HPS became nationally notifiable in 1995, and CDC reports that 890 laboratory-confirmed hantavirus disease cases were reported in the U.S. from the start of surveillance in 1993 through the end of 2023.7 A 1993–2009 U.S. surveillance analysis reported 510 laboratory-confirmed HPS cases, with annual case counts ranging from 11 to 48 cases per year, an incidence of 0.04–0.19 cases per million persons, and an overall case-fatality rate of 35%; most cases occurred in the western half of the country.8 Across the U.S. sources, the consistent exposure concern is rodent contact, especially when contaminated material is disturbed. In a 1993–2015 review of 662 U.S. HPS case-patients, reported rodent exposures occurred at home, at work, and in recreational settings; cleaning rodent-infested areas was specifically reported in 17% of case-patients, and the authors note that sweeping and vacuuming may aerosolize infectious excreta, especially in confined spaces with limited ventilation.2

The most practical prevention advice is exposure-based: avoid contact with rodent urine, droppings, saliva, and nesting material; control and exclude rodents from your residence; and clean contaminated areas using a wet disinfection method rather than dry sweeping or vacuuming. CDC recommends wearing rubber or plastic gloves, spraying urine, droppings, or nesting material with a dilute bleach solution or EPA-registered disinfectant until very wet, allowing at least 5 minutes of contact time or following the disinfectant label, wiping material up with paper towels, disposing of waste in a covered trash container, and then mopping or sponging the area with disinfectant.9

For most clients, that is the main takeaway: hantavirus prevention starts with rodent control, avoiding direct contact with rodent-contaminated material, and cleaning contaminated areas in a way that does not aerosolize urine, droppings, or nesting material.

Clients may also ask two related but separate questions: whether their pets can be infected and whether people can get hantavirus from their pets. Based on the sources reviewed here, there was no broad concern identified that domesticated animals are routinely expected to become sick from hantavirus or serve as a source of infection for people. The central risk identified in these sources is exposure to rodents and rodent-contaminated environments. Pet rats are the clear companion-animal exception because of Seoul virus, a different hantavirus carried primarily by Norway rats. CDC states that Seoul virus has been found in both pet rats and wild rat populations, that infected rats may show no clinical signs, and that they can shed virus in urine, feces, and saliva. People can become infected when exposed to rats carrying Seoul virus, and CDC recommends added precautions when veterinary staff handle rats from confirmed Seoul virus locations.4

FAQs:

The following FAQ may help veterinary teams answer common client questions and provide reliable resources for future updates. The current Hantavirus outbreak remains a constantly changing situation; for the most up-to-date information, please visit CDC Hantavirus coverage or WHO Hantavirus coverage.

Is this going to be the next COVID?

No. CDC directly states that this outbreak is not like the COVID-19 pandemic, that Andes virus does not spread easily person-to-person like COVID-19, and that the risk of a pandemic and the overall risk to the American public and travelers remain extremely low.5

Why is Andes virus getting so much attention?

Most hantavirus transmission is rodent-associated, but Andes virus is unusual because it is the only hantavirus CDC identifies as known to spread person-to-person. That spread is usually limited to close contact with a symptomatic person.5

What counts as close contact?

CDC lists prolonged direct physical contact, prolonged time in close or enclosed spaces, or exposure to saliva, respiratory secretions, or other body fluids. Examples include kissing, sharing utensils, or handling contaminated bedding from a symptomatic infected person.5

Can pets become sick from hantavirus or spread it to people?

Based on the sources reviewed here, there was no broad concern identified that domesticated animals are routinely expected to become sick from hantavirus or serve as a source of infection for people. The central risk identified in these sources is exposure to rodents and rodent-contaminated environments. Pet rats are the clear companion-animal exception because CDC states that Seoul virus can infect rats, including pet rats, and infected rats can shed virus in urine, feces, and saliva without showing clinical signs.2,4

Are pet rats a concern?

They can be, specifically for Seoul virus. CDC states Seoul virus is carried primarily by Norway rats, has been found in both pet and wild rat populations, and infected rats can shed virus in urine, feces, and saliva without showing clinical signs. CDC also notes that people can become infected when exposed to rats carrying Seoul virus.4

Should pet rats be tested because of the cruise ship outbreak?

The reviewed sources do not recommend Andes virus testing for pet rats because of the cruise ship outbreak. CDC’s veterinary rat guidance is for Seoul virus, while the Andes virus FAQ focuses testing on symptomatic people with known exposure.4,5

What risk factors should people avoid?

Avoid rodent urine, droppings, saliva, nesting materials, and unsafe cleanup of rodent-contaminated areas. The U.S. exposure review identifies home, occupational, and recreational rodent exposures, and notes that sweeping and vacuuming may aerosolize infectious excreta, especially in confined spaces with limited ventilation.2

What is the safest way to clean rodent-contaminated areas?

Do not dry sweep or vacuum rodent urine, droppings, or nesting material. CDC recommends wearing rubber or plastic gloves; spraying urine, droppings, or nesting material with a dilute bleach solution or EPA-registered disinfectant until very wet; allowing at least 5 minutes of contact time or following the disinfectant label; wiping material up with paper towels; disposing of waste in a covered trash container; and then mopping or sponging the area with disinfectant.9

Abbreviations

CDC: Centers for Disease Control and Prevention
EID: Emerging Infectious Diseases
EPA: Environmental Protection Agency
HFRS: hemorrhagic fever with renal syndrome
HPS: hantavirus pulmonary syndrome
ICTV: International Committee on Taxonomy of Viruses
WHO: World Health Organization

References

  1. Knust B, Rollin PE. Twenty-year summary of surveillance for human hantavirus infections, United States. Emerg Infect Dis. 2013 Dec;19(12):1934-7. doi: 10.3201/eid1912.131217.
  2. de St Maurice A, Ervin E, Schumacher M, et al. Exposure Characteristics of Hantavirus Pulmonary Syndrome Patients, United States, 1993-2015. Emerg Infect Dis. 2017 May;23(5):733-739. doi: 10.3201/eid2305.161770.
  3. Bradfute SB, Calisher CH, Klempa B, et al. ICTV Virus Taxonomy Profile: Hantaviridae 2024. J Gen Virol. 2024 Apr;105(4):001975. doi: 10.1099/jgv.0.001975.
  4. Centers for Disease Control and Prevention. Veterinary guidance for testing for Seoul virus in pet rats. National Center for Emerging and Zoonotic Infectious Diseases. Published 2024. Accessed May 11, 2026.
  5. Centers for Disease Control and Prevention. Andes virus outbreak on a cruise ship: frequently asked questions. National Center for Emerging and Zoonotic Infectious Diseases. Published 2026. Accessed May 11, 2026.
  6. World Health Organization. Hantavirus cluster linked to cruise ship travel, multi-country. Disease Outbreak News. Published 2026. Accessed May 11, 2026.
  7. Centers for Disease Control and Prevention. Reported cases of hantavirus disease. National Center for Emerging and Zoonotic Infectious Diseases. Published 2026. Accessed May 11, 2026.
  8. MacNeil A, Ksiazek TG, Rollin PE. Hantavirus pulmonary syndrome, United States, 1993-2009. Emerg Infect Dis. 2011 Jul;17(7):1195-201. doi: 10.3201/eid1707.101306.
  9. Centers for Disease Control and Prevention. How to clean up after rodents. Healthy Pets, Healthy People. National Center for Emerging and Zoonotic Infectious Diseases. Published April 8, 2024. Accessed May 11, 2026.

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