Fig. 3

Determination of the limit of detection of three newly developed RT-qPCRs for sequencing-independent pathotyping of Eurasian avian influenza H7 viruses (blue dots/lines) compared to a matrix gene-specific generic RT-qPCR (Hoffmann et al., 2010; black diamonds/lines). The detection limit was determined based on serial ten-fold dilutions using RNA of the reference viruses (a) A/chicken/Germany/AR1385/2015 (HPAIV H7N7), (b) A/mute swan/Germany/R901/2006 (LPAIV H7N7) and (c) A/broiler/Italy/445/1999 (HPAIV H7N1). d Detection of artificial mixtures of H7 LP and HPAIV RNA of the ‘Emsland’ outbreak compared to a matrix gene-specific generic RT-qPCR (black diamonds). RNA of the reference viruses A/chicken/Germany/AR915/2015 (LPAIV H7N7) and A/chicken/Germany/AR1385/2015 (HPAIV H7N7) were mixed and the percentage ratios indicated on the X-axis. Identification of Cq values (results of triplicate analyses) obtained for each mixture sample by H7 specific RT-qPCRs is as follows: blue circles – LPAI H7; green triangles – HPAI H7 ‘Emsland’