While the BLACKBOX CCHFV IgM ELISA and the VectoCrimean-CHF-IgM ELISA gave identical results (Table 6), the BLACKBOX CCHFV IgG ELISA was found to be more efficient than the VectoCrimean-CHF-IgG ELISA (Table 7) in detecting IgG antibodies in the “late” serum samples collected between day 8 and day 36 (median: day 17) after onset of symptoms. The gene discussed is CD40LG; the disease is congestive heart failure.