Use of heat inactivated viral haemorrhagic fever antigens in serological assays.

Heating for 1 h at 60 degrees C completely destroyed the infectivity of sucrose-acetone-extracted antigen of Rift Valley (RVF) and Congo Crimean haemorrhagic fever (CCHF), as well as of RVF- and CCHF-infected mouse brain. These antigens could be successfully used, however, for complement fixation and IgM-capturing enzyme immunoassay. Vero E6 cell suspensions infected with hantaviruses such as Hantaan 76-118, Tchoupitoulas, SR 11, GB-B, CG 18-20, Hällnäs, CG 13891, Seoul and Prospect Hill, as well as Vero cells infected with CCHF and RVF viruses, were completely inactivated after heating for 1 h at 60 degrees C. Indirect immunofluorescent antibody test results obtained on slides prepared with heat-inactivated cell suspensions correlated well with results obtained on slides prepared with unheated cell suspensions. Inactivation is a simple, rapid, economic and reproducible method for inactivation of hantaviruses and CCHF and RVF viruses, with preservation of the ability to react specifically with antibodies.