CD40LG and malaria: To evaluate assay specificity, 120 a priori CCHFV IgM/IgG negative sera originating from either healthy blood donors from Germany (Europe), Colombia (South America) and Lao PDR (Asia) (n = 77), malaria patients (n = 33) or flavivirus infected patients (n = 10) were tested along with 98 CCHFV IgM/IgG IIFT negative sera from healthy blood donors from Kosovo (Fig 3A, Fig 3B, panels A and B in S1 Fig).