Executive summary
Hantavirus disease is uncommon, but it deserves attention because it can deteriorate quickly and has no widely available curative therapy. For most clients, the practical risk is not ordinary community contact; it is rodent exposure, especially in enclosed, dusty, or infrequently used spaces such as sheds, cabins, barns, crawlspaces, warehouses, and work areas with visible infestation. Infection usually follows inhalation of aerosolized rodent urine, droppings, saliva, or contaminated dust. Person-to-person spread is rare and is mainly associated with Andes virus, usually after close, prolonged contact. Early recognition, rapid supportive care, rodent control, and safe wet-cleaning protocols are therefore the core management tools. [1–7]
Definition and virology
Taxonomically, Hantaviridae is a family within the order Bunyavirales, while Orthohantavirus is the mammalian genus that contains the hantaviruses relevant to human disease. This distinction matters because not all hantavirids are human pathogens; ICTV states that orthohantaviruses are the only hantavirids known to cause disease in humans. [1,2]
Virologically, orthohantaviruses are enveloped, single-stranded negative-sense RNA viruses with a tri-segmented genome: the small (S), medium (M), and large (L) segments encode the nucleoprotein, glycoprotein precursor that yields Gn/Gc, and RNA-dependent RNA polymerase, respectively. ECDC describes them as segmented negative-sense ssRNA viruses; ICTV describes virions as pleomorphic, mostly spherical, and typically 80–160 nm in diameter, with a membrane envelope and glycoprotein spikes. Because particle size varies somewhat by imaging method and strain, a single fixed diameter should be treated as approximate rather than absolute. [2,3]
Transmission and clinical syndromes
Transmission is primarily zoonotic. Humans are infected by breathing in virus-contaminated aerosols from infected rodents’ urine, feces, saliva, nests, or dust. Less common routes include rodent bites, contaminated hands touching eyes or mouth, broken skin exposure, and contaminated food. Each pathogenic virus is associated with a rodent reservoir, and infection risk rises during sweeping, vacuuming, or disturbing contaminated materials in enclosed spaces. WHO and ECDC are aligned that well-documented person-to-person transmission is limited to Andes virus; it remains uncommon and is linked to close, prolonged contact, especially early in illness. [2–7,21]
Clinically, hantavirus disease presents as two main syndromes. In the Americas, HPS/HCPS is a rapidly progressive cardiopulmonary illness. In Europe and Asia, HFRS primarily affects the kidneys and vasculature. Incubation is broad: WHO gives an overall range of 1–8 weeks; CDC gives 1–8 weeks for HPS and usually 1–2 weeks, rarely up to 8 weeks for HFRS; strain-specific reports place Sin Nombre virus often around 1–5 weeks, and the Epuyén Andes outbreak showed 8–31 days among confirmed cases. [4–7,11,12,15]
Virus | Reservoir | Region | Syndrome | CFR | Person-to-person note | Source |
Sin Nombre | Deer mouse (Peromyscus maniculatus) | U.S./Canada | HPS/HCPS | ~38% in U.S. respiratory cases | No documented person-to-person spread | CDC [5,7] |
Andes | Long-tailed pygmy rice rat (Oligoryzomys longicaudatus) | Argentina/Chile | HPS/HCPS | commonly ~20–40%; some outbreaks higher | Rare but documented after close, prolonged contact | WHO/UK guidance [4,11,21] |
Hantaan | Striped field mouse (Apodemus agrarius) | East Asia | HFRS | ~5–15% | No established person-to-person spread | CDC/PHAC [6] |
Dobrava-Belgrade | Field mice (Apodemus spp.) | Balkans/Central-Eastern Europe | HFRS | ~5–15% | No established person-to-person spread | CDC/ECDC [6,9] |
Seoul | Norway/brown rat (Rattus norvegicus), also black rat | Worldwide, urban and pet-rat settings | HFRS | usually <1–2% | Not known to spread person-to-person | CDC/MMWR [6,10] |
Puumala | Bank vole (Myodes glareolus) | Northern/Central Europe | mild HFRS / nephropathia epidemica | <1% | No established person-to-person spread | CDC/ECDC [6,9] |
Compiled from WHO, CDC, ECDC, and regional public-health sources. [4–7,9–11]
Syndrome | Early signs | Severe signs | Timing | Source |
HPS / HCPS | Fatigue, fever, severe myalgia; often headache, dizziness, chills, nausea, vomiting, diarrhea, abdominal pain | Cough, chest tightness, shortness of breath, pulmonary edema, hypoxia, shock | Usually begins 1–8 weeks after exposure; late respiratory phase often follows 4–10 days after initial symptoms | CDC/WHO [4,5,7] |
HFRS | Sudden headache, back/abdominal pain, fever/chills, nausea, blurred vision; sometimes flushing or rash | Hypotension, vascular leak, shock, bleeding abnormalities, acute kidney injury / fluid overload | Usually 1–2 weeks after exposure, rarely up to 8 weeks | CDC/WHO [4,6,7] |
For clients, the practical message is that both syndromes can look “flu-like” at first, so exposure history is critical. [4–7]
Diagnosis, treatment, and prevention
Diagnosis is laboratory-based because early illness is nonspecific. WHO, CDC, and EID sources converge on serology as the mainstay: hantavirus-specific IgM, rising IgG, and CDC ELISA testing are central. RT-PCR is useful during acute illness when viral RNA is detectable, and immunohistochemistry is important in tissue-based and fatal-case confirmation. In practice, the most important clinical trigger is the combination of compatible symptoms and credible rodent exposure. [4–7]
Treatment is mostly supportive. For suspected HPS/HCPS, CDC advises emergency evaluation and early ICU-level care: oxygen, cautious fluids, cardiac monitoring, ventilation if needed, and early escalation in rapidly decompensating patients. CDC notes that early ECMO in selected severe HPS cases has been associated with about 80% survival. For HFRS, management focuses on fluids, electrolytes, blood pressure support, and dialysis when required. Ribavirin has not shown benefit for HPS, but CDC and ECDC still describe evidence for benefit in some HFRS settings when given early; the evidence is mixed and syndrome-specific. [4–6]
Vaccine and therapeutic development remain active but unsettled. WHO states that there is no licensed specific antiviral treatment or globally available vaccine. ECDC notes that inactivated whole-virus vaccines against Hantaan or Seoul virus are used in China and South Korea, though EU/EEA guidance characterizes efficacy as limited; a Korean effectiveness study found moderate protection in high-risk populations. Phase 1 studies report encouraging immunogenicity for Hantaan/Puumala DNA vaccines and for an Andes virus DNA vaccine. On therapeutics, human neutralizing monoclonal antibodies and a quadrivalent antibody cocktail have shown promise in preclinical work, but none is approved for routine clinical use. [3,16–20]
Setting | Action | Source |
Home, cabin, office, warehouse, farm building | Seal gaps, remove food attractants, use traps, reduce nesting sites | WHO/ECDC [4,3] |
Before cleanup of a closed space | Ventilate before entry and cleanup | CDC materials [8] |
Routine cleanup | Wear gloves; soak droppings with disinfectant or bleach solution; wait ~5 minutes; wipe, bag, and discard | CDC [8] |
Never do | Do not dry sweep or vacuum rodent waste | WHO/CDC [4,8] |
Heavy infestation or dusty remediation | Use trained personnel; add masks/respiratory protection and controlled cleaning methods | ECDC/CDC [3,8] |
Healthcare/outbreak settings | Early case recognition, isolation when indicated, standard precautions; airborne precautions for aerosol-generating procedures | WHO [4] |
Operationally, the highest-value control is simple: never turn rodent contamination into airborne dust. [3,4,8]
Recent outbreak picture and geographic risk
The last decade’s pattern is better described as ecology- and exposure-driven clusters than as sustained human transmission. Notable events include the 2017 Seoul virus pet-rat outbreak in the United States and Canada, with 17 recent infections identified in the investigation and no deaths; the 2018–2019 Epuyén outbreak in Patagonia with 29 confirmed cases and 11 deaths and evidence consistent with person-to-person Andes virus spread; the 2019 Panama event, where WHO warned of HPS activity ahead of mass gatherings; the 2021 EU/EEA peak of 4,860 reported cases; the 2025 Mammoth Lakes, California cluster with three fatal HPS cases; and the 2026 multi-country cruise-linked cluster, where WHO and ECDC reported seven cases and three deaths as of May 4–6, 2026. [9–15,21]
For a simple choropleth map, use three official layers: CDC U.S. case distribution to show the strong west-of-the-Mississippi concentration of North American HPS; ECDC annual epidemiological-report layers to show the Northern and Central European burden dominated by Puumala virus; and WHO/PAHO or national public-health outbreak layers for southern South America, especially Argentina and Chile, where Andes virus is the key human-to-human exception. A useful overlay is a separate symbol layer for Seoul virus risk linked to urban rats and pet-rat networks, which is geographically broader than classic rural HPS maps. [5,7,9,10,14,15]
Client guidance and FAQ
For clients, the most important guidance is operational. If your organization manages vacant units, storage areas, agricultural buildings, camps, pest-control work, or travel to endemic rural areas, adopt a written rodent exclusion and wet-cleaning SOP, train staff not to sweep or vacuum droppings, and require prompt medical evaluation for any febrile or respiratory illness after rodent exposure. Hantavirus is severe, but it is also highly preventable when exposure pathways are controlled. [4–8]
Is hantavirus usually contagious between people?
No. For most hantaviruses, transmission is rodent-to-human. The main exception is Andes virus, where limited person-to-person spread has been documented after close, prolonged contact. [4,21]
When do symptoms start?
Usually within 1–8 weeks after exposure. HPS often presents after 2–4 weeks, while HFRS often appears after 1–2 weeks, though both ranges are broad. [4–7,11,12]
Is there a vaccine or cure?
No broadly available curative antiviral or globally deployed vaccine exists. Some inactivated vaccines are used in China and South Korea, and DNA vaccines and antibody therapeutics are still investigational. [3,16–20]
What should clients do now?
Focus on rodent-proofing, safe cleanup, staff training, and rapid escalation of illness after rodent exposure. Those measures are more valuable than trying to memorize every virus name. [4,8]
Limitations
The 2026 cruise-linked event is evolving, so case counts, laboratory confirmation, and transmission interpretation may change. Vaccine-efficacy estimates also vary by strain, endpoint, and study design. Where official sources differ slightly on particle size or fatality ranges, this primer prioritizes ICTV/WHO/CDC/ECDC language and presents ranges rather than false precision. [1–4,14,15]
References
- International Committee on Taxonomy of Viruses. Family: Hantaviridae. ICTV Report. 2024.
- International Committee on Taxonomy of Viruses. Genus: Orthohantavirus. ICTV Report. 2024.
- European Centre for Disease Prevention and Control. Factsheet on orthohantavirus infections. Stockholm: ECDC; 2026.
- World Health Organization. Hantavirus. Fact sheet. Geneva: WHO; 2026 May 6.
- Centers for Disease Control and Prevention. Clinician Brief: Hantavirus Pulmonary Syndrome (HPS). Atlanta: CDC; 2024 May 23.
- Centers for Disease Control and Prevention. Clinician Brief: Hemorrhagic Fever with Renal Syndrome (HFRS). Atlanta: CDC; 2024 May 20.
- Centers for Disease Control and Prevention. About Hantavirus. Atlanta: CDC; 2024 May 13.
- Centers for Disease Control and Prevention. How to Clean Up After Rodents. Atlanta: CDC; 2024 Apr 8.
- European Centre for Disease Prevention and Control. Hantavirus infection: Annual epidemiological report for 2021. Stockholm: ECDC; 2025 Mar 6.
- World Health Organization. Seoul virus – United States of America and Canada. Disease Outbreak News. Geneva: WHO; 2017 Feb 20.
- World Health Organization. Hantavirus disease – Argentina. Disease Outbreak News. Geneva: WHO; 2019 Jan 23.
- World Health Organization. Hantavirus disease – Panama. Disease Outbreak News. Geneva: WHO; 2019 Jan 4.
- Mono County Public Health. Third Hantavirus-Related Death Confirmed in Mono County. Mono County, California; 2025 Apr 3.
- World Health Organization. Hantavirus cluster linked to cruise ship travel, Multi-country. Disease Outbreak News. Geneva: WHO; 2026 May 4.
- European Centre for Disease Prevention and Control. Hantavirus-associated cluster of illness on a cruise ship: ECDC assessment and recommendations. Stockholm: ECDC; 2026 May 6.
- Hooper JW, et al. Phase 1 clinical trial of Hantaan and Puumala virus DNA vaccines delivered by needle-free injection. npj Vaccines. 2024.
- Jung J, et al. Protective effectiveness of inactivated hantavirus vaccine in high-risk populations residing in endemic area. J Infect Dis. 2018.
- Paulsen GC, et al. Safety and immunogenicity of an Andes virus DNA vaccine by needle-free injection. Phase 1 clinical trial. 2023.
- Engdahl TB, et al. Broad and potently neutralizing monoclonal antibodies isolated from human survivors of New World hantavirus infection. Cell Reports. 2021.
- Brocato RL, et al. Preclinical evaluation of a fully human, quadrivalent neutralizing antibody therapeutic against hantaviruses. 2024.
- Martínez VP, et al. “Super-spreaders” and person-to-person transmission of Andes virus. N Engl J Med. 2020.