An epidemiological survey of nephropathia epidemica in Sweden.

The indirect immunofluorescence test (IFT) using the Hantaan virus (agent of Korean hemorrhagic fever, KHF) was applied for detection of antibodies to nephropathia epidemica (NE). From 103 patients with symptoms suggesting NE, 61% revealed KHF/NE antibodies in the convalescent sera. All seropositive patients seemed to have acquired their disease in NE endemic areas (north of the 60th parallel). Only patients found to have a typical clinical NE (fever, abdominal pain and renal engagement) were seropositive. Antibodies to KHF/NE were found in 4.2% of sera from 647 healthy persons living in NE endemic areas. Signs of local clusters were found. Subclinical or mild disease seems common. Proof of man to man spread of the disease was not found. Sera from 355 persons living outside NE endemic areas were also tested and 2.4% contained KHF/NE antibodies.