FIG. 3.

(A) Global distribution and phylogenetic relationships of CCHF virus strains selected for the design and validation of the assay. Phylogenetic analysis was based on 450-bp sequences of the CCHF virus S segment available in the NCBI database, and the phylogenetic tree was generated by the neighbor-joining method with TreeCon for Windows, version 1.3b (Yves van de Peer, University Konstanz, Germany). *, these CCHF virus strains were not available for testing with the novel universal CCHF virus quantitative RT-PCR assay, but genetically closely related isolates have been tested. **, strain AP92 has also not been available for testing. It was isolated from a Rhipicephalus bursa tick and has never been associated with human disease. (B) Representative hybridization patterns of CCHF virus strains listed in Table 2. Different strains of CCHF virus show individual hybridization patterns on the macroarray. However, these patterns are based only on sequence variability within an approximately 25-nt region of the CCHF virus S segment. Therefore, they cannot be considered unique for a specific CCHF virus strain, as shown in patterns 5 and 6. Dugbe virus, a nonpathogenic nairovirus closely related to CCHF virus, is not detected by the CCHF virus-specific array. Note that the internal control spots are not visible in the CCHF virus patterns, as the amplification of the internal control RNA is suppressed in the presence of high concentrations of CCHF virus RNA (also compare Fig. 2).