Figure 6. Viral shedding trajectories and antibody titres from Line 0 birds challenged with different LPAI viruses and their respective contact sentinels.

Viral shedding from Line 0 birds was measured in directly infected (continuous line) or contact sentinel birds (dashed line). Oropharyngeal shedding of H7N7 (A), H9N2/Wis (B) or H9N2/UDL (C); cloacal viral shedding of H7N7 (D), H9N2/wis (E) or H9N2/UDL (F). Results are represented as the mean of Ct (cycle threshold) value obtained by qRT-PCR of the influenza matrix gene (n = 10 for each group within each virus). Influenza-specific antibody titres from serum samples from infected (continuous line) and sentinels birds (dashed line) exposed to H7N7 strain (G), H9N2/wis (H) or H9N2/UDL (I) were measured by haemagglutination inhibition assay and represented as mean ± S.E.M of HAI titre.