Figure 4. Virus titers in oropharyngeal and cloacal swabs of infected ducks.

Six shelducks (12 week-old) were inoculated intranasally with the viruses at 10⁶ EID₅₀. Three naïve ducks were introduced into the isolators later that day. Virus shedding in the respiratory and gastrointestinal tracts of both challenge and contact groups was monitored using oropharyngeal (OP) and cloacal (CL) swabs, respectively, taken at 2, 4, and 6 (4 and 6 dpc. for the contact group) days post-inoculation (p.i).