PREVALENCE OF SERUM ANTIBODIES TO HANTAVIRUSES IN NORTHERN SWEDEN AS MEASURED BY RECOMBINANT NUCLEOCAPSID PROTEINS

An enzyme-linked immunosorbent assay (ELISA) based on recombinant nucl eocapsid protein (rN Delta) (aa 1-117) of Hantaan, Seoul, Dobrava, Sin Nombre and Puumala hantaviruses nas used to determine the prevalence of antibodies among randomized and stratified individuals from norther n Sweden. In total, 137/1533 individuals (8.9%) had specific serum Ige antibodies to Puumala virus, the only hantavirus known to occur in th e region. The prevalence of antibodies to Puumala virus (8.9%) was det ermined to be higher than previously reported (5.4%) in the same serum material, by use of immunofluorescence assay. As expected, sera react ive to Puumala virus rN Delta did frequently cross-react with Sin Nomb re virus protein. Unexpectedly, 21/1533 (1.4%) individuals recognized the Sin Nombre virus rN Delta exclusively. Another 8 subjects showed r eactivity in the ELISA to Hantaan, Seoul, or Dobrava virus-derived rN Delta but not to Puumala virus or Sin Nombre virus rN Delta. The prese nt demonstration in some individuals of antibodies specifically recogn izing the Sin Nombre, Dobrava, Hantaan and Seoul virus protein justifi es an awareness of the possibility that hantaviruses antigenically dif ferent from Puumala virus might occur in the region.