Hantavirus, originally named after the Hantaan River in Korea, is the aetiologic agent for the Hemorrhagic Fever with Renal Syndrom (HFRS) in the asian region, in the Americas for the Hantavirus Pulmonary Syndrom (HPS). In Middle Europe hantaviruses are responsible for the "Nephropathia Epidemica" (NE), a mild form of HFRS. Hantaviruses belong to the family of Bunyaviridae. Like other members of this family their genome consists of three segments of single stranded RNA (ss-RNA) leading to various subtypes, strongly associated with different rodent hosts. There are two major groups, the hantaan lineage harbored by murine rodents and the Puumala lineage harbored by arvicolidae ("old world") and sigmodontidae ("new world"). Infected rodents may develop chronic infections for months or even life-long and may shed infectious virus with urine and feces. The primary mode of infection of man occurs by inhaling contaminated aerosols or soil particles. The collection of epidemiologic data in the state of Baden-Wurttemberg was realized in three different steps: Collection and localisation of clinical cases (n = 62): A concentration of clinical cases in the middle of the state was found. The examination of the seroprevalence of exposed persons: By the examination of 4000 sera from forest workers, a seroprevalence with an average of 2,1% was found. In the districts of Reutlingen and Tubingen seroprevalences up to 9% were found. This leads to the assumption that there are endemic areas. Epidemiologic studies of reservoir hosts: Serologic surveys of rodents (n = 1150) in the described areas yielded to a seroprevalence up to 10-30%. Virus carriers were determined with RT-PCR and nested-PCR testings. The prevalence in the rodent population showed an average of 10%. The isolated subtypes were all identified as members of the Puumala-lineage. The origin of sporadic infections with Hantavirus of the Hantaan-lineage ire Baden-Wuerttemberg is still unknown.
