Diagnostic performance characteristics (field samples). Diagnostic performance characteristics of a newly developed H5-specific multiplex RT-qPCR for detection and differentiation of clade 2.2.1p proper (black triangles) and 2.2.1v variant HPAIV H5N1 strains (open triangles) from Egypt compared to standard H5 RT-qPCR . The analysis comprises 50 M-PCR positive field samples obtained within the frame of the Egyptian poultry surveillance program from commercial poultry farms (n = 11) and backyard holdings (n = 39). See Additional file 4, Table S4, for individual values. Grey dots represent samples in which both clades were detected. X-axis: Ct-values obtained by the generic H5 RT-qPCR . Y-axis: Ct-values generated by the specific component of the multiplex RT-qPCR as indicated above each graph.