Is hantavirus in the US right now? Yes, and it has been every year since the Sin Nombre virus was first identified in 1993. In 2026, the US is dealing with two distinct hantavirus situations simultaneously: the ongoing domestic Sin Nombre season in western states, and one fatal Andes virus case linked to the MV Hondius cruise ship. Here is the complete picture, with CDC guidance and a state-by-state risk breakdown.
The US Hantavirus Situation in 2026
As of May 14, 2026, the CDC reports:
- 19 domestic hantavirus pulmonary syndrome (HPS) cases — all caused by Sin Nombre virus, acquired in the US
- 1 Andes virus death — a passenger on the MV Hondius cruise ship who was medically evacuated to a US hospital and died
- Total 2026 US hantavirus deaths: 4 (3 domestic Sin Nombre + 1 Hondius Andes)
The domestic case count is running slightly below the five-year average (typically 20–30 cases per year). The Hondius-linked death is a separate epidemiological event and does not indicate that Andes virus is circulating in the US environment.
Sin Nombre Virus: The US’s Own Hantavirus
Sin Nombre virus (SNV) is the dominant hantavirus in the United States. It is carried by the deer mouse (Peromyscus maniculatus), which is found across virtually the entire western United States and much of the Great Plains and Rocky Mountain regions.
Key facts about Sin Nombre:
- Does not spread person-to-person (unlike Andes virus)
- Causes Hantavirus Pulmonary Syndrome (HPS) — same clinical syndrome as Andes, but no P2P risk
- Case fatality rate: approximately 35–38%
- No vaccine, no specific antiviral treatment
- Transmission: aerosol from deer mouse urine, faeces, or saliva in enclosed spaces
2026 US Hantavirus Cases by State
Based on CDC surveillance data through May 14, 2026:
| State | 2026 Cases | YTD Deaths | Historical Burden |
|---|---|---|---|
| New Mexico | 4 | 1 | Highest per capita nationally |
| Colorado | 3 | 1 | Four Corners region endemic |
| Arizona | 3 | 0 | Consistent annual cases |
| California | 2 | 0 | Yosemite legacy; cabin risk |
| Texas | 2 | 0 | West Texas endemic zone |
| Utah | 1 | 0 | Rocky Mountain foothills |
| Washington | 1 | 0 | Eastern WA rural area |
| Montana | 1 | 1 | Ranch worker exposure |
| Idaho | 1 | 0 | Rural agricultural setting |
| Wyoming | 1 | 0 | Near Yellowstone region |
All 19 domestic cases were acquired in rural or semi-rural settings through contact with deer mouse-contaminated environments — abandoned buildings, barns, campsites, or infested homes.
State-by-State Risk: Where Is Hantavirus US Risk Highest?
The CDC’s long-term data (1993–2026) identifies the Four Corners region — where New Mexico, Colorado, Arizona, and Utah meet — as the highest-risk area for hantavirus in the US. The region accounts for more than 40% of all historical US HPS cases.
Tier 1 — Highest risk (multiple cases most years):
- New Mexico, Colorado, Arizona, Utah
- Why: High deer mouse density, rural housing with poor rodent exclusion, dry conditions that concentrate mice indoors in summer and autumn
Tier 2 — Moderate risk (1–5 cases most years):
- California, Texas, Montana, Idaho, Wyoming, Washington, Oregon
- Why: Deer mice present but lower density or different land-use patterns
Tier 3 — Low but non-zero risk (sporadic cases):
- Great Plains states (Kansas, Nebraska, South Dakota, North Dakota)
- Appalachian states (rare cases, different rodent species)
Eastern US: Very low risk. The deer mouse (Peromyscus maniculatus) is largely absent east of the Mississippi. Peromyscus leucopus (the white-footed mouse) carries a closely related virus but causes much milder disease and rarely HPS.
What the France P2P Confirmation Means for the US
On May 14, 2026, Santé publique France confirmed person-to-person transmission of Andes virus in a Lyon household — both patients were MV Hondius passengers. This does not affect domestic US hantavirus risk from Sin Nombre virus, which has never been documented to spread person-to-person.
However, the CDC has issued updated guidance relevant to:
- US Hondius passengers and contacts: any symptomatic Hondius-linked person should now be managed under contact and droplet precautions, not just standard precautions
- Clinicians treating Hondius contacts: droplet precautions from the moment of clinical suspicion, not just after confirmation
- Household contacts of Hondius-linked cases: avoid close physical contact and sharing of food/utensils with a symptomatic individual pending testing
For the domestic Sin Nombre situation, nothing changes — Sin Nombre does not spread person-to-person and existing clinical guidance remains appropriate.
CDC’s Current Public Guidance for Americans
The CDC’s active guidance for US residents in 2026 covers two scenarios:
If you live or work in a hantavirus-endemic area (western US):
- Do not sweep or vacuum rodent droppings — wet them down with a 1:10 bleach solution first, wear gloves and an N95 respirator, ventilate the space thoroughly
- Seal cracks and holes in buildings larger than a pencil diameter
- Remove potential food sources (unsecured grain, birdseed, compost) that attract deer mice
- Use snap traps inside buildings rather than poison baits, which leave dying mice in inaccessible spaces
- See a doctor immediately for any fever and deep muscle aches if you have had potential rodent exposure
If you were aboard MV Hondius:
- Monitor for symptoms — fever, fatigue, muscle aches (especially thighs and hips) — for 45 days from last exposure
- Seek emergency care immediately if symptoms develop; tell your doctor about the cruise
- Until Andes virus is ruled out, follow household isolation precautions: avoid kissing, sharing food, or prolonged enclosed-space contact with household members
When to See a Doctor
The CDC’s threshold for seeking care is explicit: fever plus significant muscle aches within 6 weeks of rodent exposure or Hondius disembarkation. Do not wait for shortness of breath — by that stage, HPS has entered its most dangerous phase.
Call ahead to your emergency department so they can prepare isolation protocols before you arrive. A single RT-PCR test on a blood sample can confirm or exclude hantavirus within 24–48 hours at most major US hospital laboratories.
Live US and global case counts on our interactive map →
Explore HantavirusMap