In summer 2012, the American National Park Service reported an outbreak of hanta virus in Yosemite national park, California. Nine visitors to the park developed the life threatening deadly pulmonary syndrome, three of them died. Hanta virus is also present in Europe. But how deadly is it over here?
Published in: EOS magazine 11, 2012 (in Dutch: Wie is bang van hantavirus?- pdf)
We talked to researchers from the University of Antwerp and the Dutch Rijksinstituut voor Volksgezondheid en Milieu. They explained that hanta viruses in Europe are mostly Puumala hanta viruses, as opposed to the American Sin Nombre virus. Also, while the Sin Nombre virus is transmitted by deer mice, the hosts for Puumala virus are bank voles. But most importantly, an infection with Puumala virus leads to much milder symptoms than the potentially deadly infection with Sin Nombre virus. While the infection risk with hanta virus is much greater in Europe, less than 30% of infected people become ill. The infection risk for the Sin Nombre virus is much smaller, but 38% of infected people in America die.
Since 2005, the number of people developing nephropathia epidemica increase in most European countries. For example, in Belgium the prevalence increased from 100 to more than 300 cases each year. The prevalence of nephropathia epidemica in Europe greatly differs geographically, but also in time. Katrien Tersago from the University of Antwerp discovered that the prevalence of nephropathia epidemica in Belgium is not only linked to the presence of bank voles and the human sensitivity as a result of specific behaviour, but also to environmental factors that influence the transmission of the virus. Tersago investigates how outbreaks of hanta virus can be predicted. Together with other European research partners, she develops models that should act as early warning tools of epidemics.
Table: what makes the difference between the Sin Nombre hanta virus and the Puumala hanta virus?
|Hantavirus species||Geographical distribution||Clinical symptoms||Host||Mortality risk upon infection|
|Sin nombre virus||America||Hanta virus pulmonary syndrome (breathing and heart problems)||Deer mouse||38%|
|Puumala virus||Europe and Asia||Nephropathia epidemica (hemorrhagic fever and kidney failure)||Bank voles||<1%|
Figure: Number of illnesses In Belgium upon hanta virus infection (per 100.000 inhabitants and per district, for the period 2007-2011). Source: WIV, FOD Volksgezondheid and Surveillance, and Peillaboratoria and Referentielaboratorium).