What is hantavirus?
Hantavirus is an RNA virus belonging to the Hantaviridae family. It is transmitted to humans through contact with infected rodents, primarily via inhalation of viral particles present in their droppings, urine or saliva. In Belgium and Europe, the most widespread strain is the Puumala virus, carried by the bank vole (Myodes glareolus).
History and discovery
Hantavirus takes its name from the Hantaan River in South Korea, where it was first identified in 1978 during an epidemic that affected American soldiers during the Korean War. In Europe, the earliest clinical descriptions of epidemic nephropathy date from the 1930s in Scandinavia, long before the causative virus was identified.
Strains present in Europe
Three main strains circulate in Europe:
- Puumala: present in Belgium, Scandinavia, France and Germany. It causes Hemorrhagic Fever with Renal Syndrome (HFRS), generally mild. Reservoir: bank vole.
- Dobrava: present in central and Balkan Europe. More virulent, with higher mortality. Reservoir: yellow-necked mouse (Apodemus flavicollis).
- Seoul: present worldwide via common rats (Rattus norvegicus). Sporadic cases in Europe, often linked to rat breeding.
How is it transmitted?
Transmission occurs primarily through the airborne route. When contaminated materials (faeces, urine, rodent bedding) dry out and are disturbed, micro-particles disperse into the air and can be inhaled.
At-risk situations include:
- Cleaning attics, cellars, barns or garden sheds without respiratory protection
- Agricultural or forestry activities (grain storage, woodwork)
- Camping and hiking in forests, especially in the Ardennes
- Handling firewood stored outdoors
- Renovating old or abandoned buildings
The virus does not spread person-to-person, except for the Andes strain found in South America.
Who is at risk?
Anyone exposed to wild rodents or their droppings can be infected. In Belgium, the most exposed groups are:
- Farmers and forestry workers
- Construction workers during building renovations
- Cleaning staff in abandoned or disused premises
- Veterinarians and field biologists
- Outdoor enthusiasts in the Ardennes (hikers, hunters)
Epidemiology in Belgium
Key figures for Belgium:
- 50 to 300 cases reported per year on average
- Numbers surge during high vole density years (so-called rodent years)
- Most affected provinces: Luxembourg, Namur and Liège
- Mortality rate below 1% for the Puumala strain
What to do if you suspect infection?
If you have been exposed to rodents and develop symptoms, act quickly:
- Consult a doctor promptly — do not wait
- Mention possible rodent exposure explicitly
- State that you used SymptomChecker.be to assess your symptoms
- Ask for an IgM anti-hantavirus serology blood test