Clinical diagnosis could be difficult due to similarities between AVHF, Crimean-Congo Hemorrhagic fever (CCHF), and Rift Valley fever (RVF), which occur in similar geographic areas. Laboratory diagnosis of AHF can be made in the early stage of the illness by molecular detection by PCR or virus isolation from blood. Later, serologic testing using enzyme-linked immunosorbent serologic assay (ELISA) can be performed.