Figure 2.

Buccal and cloacal H7N9 viral shedding (mean (line) and individual bird (symbols)) during direct- and contact-infection. (a,b and c) denote the three pens where doses of 8, 8 and 6 log₁₀EID₅₀ per bird were directly administered to the D0 group (n = 6) in each pen, namely chickens (ck), turkeys (ty) and turkeys respectively. R1 (n = 6) and R2 (n = 4) contact groups were introduced to each pen at 1 and 4 dpi respectively, in order to attempt the transmission: (a) D0 ck- > R1 ck- > R2 ty; (b) D0 ty- > R1 ty- > R2 ty and (c) D0 ty- > R1 ty- > R2 ty. Blue circles, green triangles and red squares indicate D0, R1 and R2 individual birds’ shedding titres respectively. See Fig. 1 and Methods section for planned withdrawl times of D0, R1 and R2 groups, with blue and pink shading indicating the D0/R1 and R1/R2 cohousing periods respectively. Arrows indicate final sampling of R1 and R2 turkeys in (b) and (c) which were either found dead or required euthanasia (Fig. 3). Broken horizontal line indicates the threshold for viral RNA REU shedding values.