Doctors warn of Hanta virus infections during spring cleaning
Again and again, reports of an increased occurrence of Hanta virus infections have caused a sensation in recent years. In a current announcement, scientists from the Goethe University Frankfurt am Main warn of the risk of infection, which is caused, among other things, by the dust raised during spring cleaning.
"If you inhale dust during spring cleaning, you are exposed to an increased risk of infection from Hanta viruses in some areas of Germany," the university said. Because there can also be excretions of the red vole in the dust. If the dust contaminated with viruses is whirled up and inhaled, for example, during cleaning work in agriculture and forestry, an infection can occur. Using long-term data series, the scientists at the Goethe University and the Senckenberg Biodiversity and Climate Research Center evaluated the development of Hanta virus infections in Germany. Their results were published in the specialist magazine "PeerJ".
Red-headed mice the main transmitter
In Germany, the Hanta viruses (Puumala virus; PUUV) are transmitted primarily by the red vole (Myodes glareolus), the scientists explain. The mouse itself does not get sick, but can pass the pathogen on to humans in various ways. For example, infection from the bite of a vole is possible. Residues of faeces and urine, as well as aerosols containing pathogens, which are whirled up and inhaled with the dust, also form a possible infection route, according to the researchers. The infections are particularly dangerous because of the hemorrhagic fever and the increased tendency to bleed, which can lead to acute kidney failure.
Spatial, temporal and seasonal patterns of infections
Hanta virus infections have had to be reported in Germany since 2001. Based on the data obtained, the research team led by Prof. Sven Klimpel from the Institute for Ecology, Evolution and Diversity at Goethe University has now tried to identify spatial, temporal and seasonal patterns for the occurrence of the infection. According to the scientists, a large number of Puumala virus infections can be identified in Baden-Württemberg and neighboring areas in Bavaria and North Rhine-Westphalia, while only a few PUUV virus cases occur in northeastern Germany. In addition, the number of infections per 100,000 inhabitants tends to be higher in large cities and metropolitan areas than in rural areas. According to the researchers, these spatial patterns have hardly changed in the past 15 years.
Population density of the mice is crucial
While the spatial distribution patterns are relatively constant, according to the scientists, there were strong temporal fluctuations. For example, the reported PUUV infections were particularly high in 2007, 2010 and 2012. An important factor is the red vole density, which in turn depends on land use (especially the forest share), climatic factors (temperature in winter) and the food supply. Here, years in which beech, oak and chestnut produce a particularly large number of fruits (mast years) are of crucial importance. Because a rich food supply for the disease carriers usually leads to a sharp increase in population density and thus to more infected rubella, which ultimately also increases the risk of infection for humans.
Increased infections in early summer
In their investigations, the researchers found that the infectious years 2007, 2010 and 2012 were actually preceded by corresponding fattening years. In the fattening year 2014, however, there was only a slight increase in human Puumala virus infections, the scientists report. "Due to the complex relationships and the multitude of factors that influence the number of Puumala virus infections, it is currently still difficult to create a reliable prediction model," said the University of Frankfurt. However, the correlation analyzes clearly show a higher risk for wooded areas, for early summer and for years that follow a fattening year. "Due to climate change, which means more frequent fattening years and milder winters, the number of Puumala virus infections could increase in the future," warns Prof. Klimpel. (fp)