In its recent epidemiological bulletin (no. 15) the German Robert Koch Institute reports about exceedingly high numbers of hantavirus infections in Germany. In total, 1,713 cases had been registered in 2017 – in the previous year, there were only 298.

Indeed, the number of infections fluctuates considerably from year to year. Also 2007, 2010 and 2012 were years with comparable or even higher case numbers. The reason for this up-and-down is the variation in population size of the rodents which transmit the virus to humans. Their population size in turn depends on the annual food availability.

Infection with the hantavirus

Depending on the country and region, different hantavirus serotypes are transmitted by different mouse and rat species. The bank vole is the predominant source of infection in Southern and Western Germany. It transmits the hantavirus type Puumala virus. In the Northeast however, infections with the Dobrava Belgrade virus are more frequent, which is hosted by the striped field mouse.

The viruses, which cause persistent but clinically unapparent diseases in the rodents, are egested with their saliva and excrements. Humans mostly get infected by inhalation of dust and soil contaminated with the excretions of infected rodents, for example during gardening.

Symptoms and diagnostics of hantavirus infections

In most cases of human hantavirus infections the disease is not recognized as such. Sickness usually manifests with abruptly starting high fever that lasts for about 3 to 4 days and unspecific flu-like symptoms, e.g. headache, muscle pain and shivering. Subsequently, failure of kidney or lung function may occur, which can be lethal in the worst case. In Puumala or Dobrava Belgrade virus infections kidney involvement is more prominent.

To avoid severe complications a timely diagnosis of the viral disease is required. Diagnosis is usually based on the clinical picture and serological analyses. For detection of specific anti-hantavirus antibodies (IgM, IgG), EUROIMMUN offers diverse diagnostics products: ELISA, immunoblots and immunofluorescence tests.