[Hantavirus infections]

Abstract

Hantaviruses are enveloped single-stranded ribonucleic acid (RNA) viruses that belong to the family Bunyaviridae. They are widely distributed and maintained in populations of specific insectivores or rodent host species (mice or rats). In their natural host, hantaviruses develop persistent and asymptomatic infections with lifelong virus shedding in excreta. Transmission to humans occurs via direct contact with faeces, urine and saliva of infected rodents, in particular by inhaling virus contaminated aerosol. There are a variety of virus types that occur in different geographic areas, dependent on the natural distribution of the host. Unlike asymptomatic infection in rodents, several types of hantaviruses cause acute febrile diseases in humans, known as haemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). In Germany, human hantavirus infections frequently represent as nephropathia epidemica (NE), a generally mild HFRS form with influenza-like symptoms such as fever, myalgia, headache and gastrointestinal disorders. Kidney failure, a characteristic sign of hantavirus infections, is also common. German NE cases are primarily caused by Puumala viruses (PUUV) which naturally persist in the bank vole, a mouse species that is widely distributed in the whole area of Germany. During 2005 and 2007, in several regions of Southern and Western Germany there was an unexpected increase in PUUV-associated NE cases. Currently, 1687 symptomatic hantavirus infections have been reported until the end of 2007, which is the highest number of hantavirus diseases in Germany since the introduction of the German infection protective law (Deutsches Infektionsschutzgesetz) in 2001. Treatment of hantavirus infections is mainly supportive and involves intensive medical care. A specific antiviral therapy with ribavirin has been shown to be successful for treatment of HFRS patients in the early stage of disease. In Germany, there is no licensed vaccine applicable for the prevention of hantavirus diseases. Anti-infectious measures are, therefore, regarded to be the most effective strategy to prevent illnesses due to these emerging RNA viruses.