Preparation and use of monoclonal antibodies for identifying Crimean-Congo hemorrhagic fever virus.

Seven monoclonal antibodies were prepared against a South African strain of Crimean-Congo hemorrhagic fever (CCHF) virus and were found to be directed against viral nucleocapsid protein. Five of the monoclonal antibodies reacted to high titer in indirect immunofluorescence (IF) tests and enzyme-linked immunosorbent assays (ELISA) with 22 strains of CCHF virus and failed to cross-react with the closest antigenic relative of CCHF, Hazara virus, or with 4 other nairoviruses which need to be distinguished from CCHF virus in Africa. These antibodies, used in the IF technique, readily detected antigens induced by all strains of CCHF virus included in the study in cell culture monolayers and mouse brain tissue, which represent the systems commonly used for isolation of CCHF virus. The IF technique with monoclonal antibodies constitutes a rapid and specific means of identifying newly isolated strains of CCHF virus.