title: Serological survey of Seewis virus antibodies in patients suspected for hantavirus infection in Finland; a cross-reaction between Puumala virus antiserum with Seewis virus N protein?
abstract: Puumala virus (PUUV, carried by Myodes glareolus) co-circulates with Seewis virus (SWSV, carried by Sorex araneus) in Finland. While PUUV causes 1000-3000 nephropathia epidemica (NE) cases annually, the pathogenicity of SWSV to man is unknown. To study the prevalence of SWSV antibodies in hantavirus fever-like patients' sera, we used recombinant SWSV nucleocapsid (N) protein as the antigen in ELISA, immunofluorescence assay (IFA) and immunoblotting. While characterizing the recombinant SWSV N protein, we observed that a polyclonal rabbit antiserum against PUUV N protein cross-reacted with SWSV N protein and vice versa. We initially screened 486 (450 PUUV-seronegative and 36 PUUV-seropositive) samples sent to Helsinki University Hospital Laboratory for PUUV serodiagnosis during 2002 and 2007 in an SWSV N protein IgG ELISA. In total, 4.2 % (19/450) of the PUUV-seronegative samples were reactive in the SWSV N protein IgG ELISA and none of the tested samples [43 PUUV-seronegative (weakly reactive in the SWSV IgG ELISA) and 15 random] were reactive in the SWSV N protein IgM ELISA. None of the IgG reactions could be confirmed by IFA or immunoblotting. Furthermore, among the 36 PUUV-seropositive samples three were reactive in SWSV N protein IgG and ten in SWSV N protein IgM ELISA. One PUUV-seropositive sample reacted with SWSV N protein in IFA and four in immunoblotting. Finally, we applied competitive ELISA to confirm that the observed reactivity was due to cross-reactivity rather than a true SWSV response. In conclusion, no evidence of SWSV infection was found among the 486 samples studied; however, we did demonstrate that PUUV antiserum cross-reacted with shrew-borne hantavirus N protein.
authors: 1Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
authors: Jiaxin
authors: J
authors: Ling
authors: 1Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland 2Department of Virology and Immunology, HUSLAB, Helsinki University Hospital.
authors: Antti
authors: A
authors: Vaheri
authors: 1Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
authors: Satu
authors: S
authors: Hepojoki
authors: 1Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
authors: Lev
authors: L
authors: Levanov
authors: 1Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland 2Department of Virology and Immunology, HUSLAB, Helsinki University Hospital.
authors: Anne
authors: A
authors: Jääskeläinen
authors: 3Natural Resources Institute, Vantaa, Finland.
authors: Heikki
authors: H
authors: Henttonen
authors: 1Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland 2Department of Virology and Immunology, HUSLAB, Helsinki University Hospital 4Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
authors: Olli
authors: O
authors: Vapalahti
authors: 1Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
authors: Tarja
authors: T
authors: Sironen
authors: 1Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
authors: Jussi
authors: J
authors: Hepojoki
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology; D003411:Arvicolinae; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D007312:Eulipotyphla; D005260:Female; D005387:Finland / Q000453:epidemiology; D019084:Fluorescent Antibody Technique, Indirect; D006476:Orthohantavirus / Q000276:immunology*; D018778:Hantavirus Infections / Q000453:epidemiology* / Q000276:immunology* / Q000821:virology; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D019251:Nucleocapsid / Q000276:immunology; D029262:Puumala virus / Q000276:immunology*; D011817:Rabbits; D016036:Seroepidemiologic Studies; D012788:Shrews / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M