How many hantavirus cases occur worldwide each year?

Hemorrhagic Fever with Renal Syndrome (HFRS), the dominant hantavirus disease in Asia and Europe, accounts for an estimated 200,000 cases globally per year, with the majority in China. HPS cases in the Americas are far fewer in absolute number, at roughly 200-300 per year across the continent.

What is Seoul virus and why is it different?

Seoul virus is a hantavirus strain carried by the common Norway rat (Rattus norvegicus). Because Norway rats have spread worldwide through human trade, Seoul virus is the only hantavirus strain with a truly global distribution. It causes a mild to moderate form of HFRS and has been found on every inhabited continent.

Which hantavirus strain is most deadly?

Sin Nombre virus, which causes HPS in North America, has the highest case fatality rate at approximately 38 percent. Among HFRS strains, Hantaan virus carries the highest mortality at up to 15 percent. Puumala virus, common in Northern Europe, causes a generally milder illness with less than 1 percent fatality.

Hantavirus Around the World: Global Strains and Risk by Country

If you're dealing with a rodent problem in the US, the strain you're most likely to encounter is the Sin Nombre virus — the one behind the severe lung disease called HPS. That's the one with the 38% fatality rate. That's the one worth understanding first.

But hantavirus isn't just a US problem. Different strains exist around the world, some more dangerous than others. Here's what's out there globally and which regions carry real risk.

The Americas: Hantavirus Pulmonary Syndrome

In North and South America, hantavirus causes Hantavirus Pulmonary Syndrome (HPS), characterized by rapid respiratory failure and a case fatality rate of approximately 38 percent.

Sin Nombre virus is the dominant strain in the United States, carried by the deer mouse. Related strains causing HPS in other parts of the Americas include Black Creek Canal virus (Florida, cotton rat), Bayou virus (southeastern US, rice rat), and New York virus (northeastern US, white-footed mouse).

Andes virus, found in Argentina and Chile, is notable for being the only hantavirus strain with documented person-to-person transmission.

Across the Americas as a whole, HPS cases number in the low hundreds per year.

Asia and Europe: Hemorrhagic Fever with Renal Syndrome

HFRS is the dominant form of hantavirus disease outside the Americas. It primarily affects the kidneys rather than the lungs. Annual case counts are estimated at approximately 200,000 globally, with China accounting for the large majority.

Hantaan Virus

Found primarily in East and Southeast Asia, carried by the striped field mouse (Apodemus agrarius). Case fatality rate ranges from approximately 5 to 15 percent. The most severe HFRS-causing strain.

Puumala Virus

Circulates across Northern and Central Europe, carried by the bank vole (Myodes glareolus). Causes a generally mild form of HFRS known in Scandinavia as "nephropathia epidemica." Case fatality rate typically below 1 percent. Finland, Sweden, and Russia's western regions report the highest European case counts.

Dobrava Virus

Found in the Balkans and parts of Central Europe, carried by the yellow-necked mouse (Apodemus flavicollis). Causes more severe HFRS than Puumala.

Seoul Virus: The Worldwide Strain

Seoul virus occupies a unique position in hantavirus epidemiology. It is the only hantavirus strain with a genuinely global distribution, carried by the Norway rat (Rattus norvegicus) which has been transported worldwide through shipping and trade.

Seoul virus causes a moderate form of HFRS with a case fatality rate typically below 1 percent. In the United States, Seoul virus infections have been documented in people who keep rats as pets or work with laboratory rat colonies — not in hikers or campers, but in suburban and urban households. That's worth noting: if you keep pet rats, Seoul virus is the strain relevant to you, not Sin Nombre. It changes the assumption that hantavirus is strictly a wilderness problem.

Comparing Strains: Mortality and Disease Burden

The short version: North American strains kill at a far higher rate per infection, but Asian and European strains infect far more people overall. The 200,000 annual HFRS cases globally dwarf the low hundreds of HPS cases in the Americas — but if you're the one who gets HPS, the 38% fatality rate is what matters.

Strain	Region	Reservoir	Syndrome	Fatality Rate
Sin Nombre	North America	Deer mouse	HPS	~38%
Andes	South America	Long-tailed rice rat	HPS	~25-35%
Hantaan	East/Southeast Asia	Striped field mouse	HFRS	5-15%
Dobrava	Balkans/Central Europe	Yellow-necked mouse	HFRS	5-12%
Seoul	Worldwide	Norway rat	HFRS	<1%
Puumala	Northern/Central Europe	Bank vole	HFRS	<1%

Surveillance and Reporting Gaps

Global case counts should be treated as floor estimates. HFRS in rural Asia is almost certainly underdiagnosed — reliable testing isn't available in all regions, and mild cases may be attributed to other causes. The CDC's US HPS numbers are more reliable, running approximately 20 to 40 confirmed cases per year in recent years.

Official Sources

WHO Hantavirus Fact Sheet — global disease burden and strain distribution
CDC Hantavirus — HPS surveillance data

Hantavirus Around the World: Which Countries and Strains Pose the Most Risk