Figure 1.

Representation of the experimental design describing the two experiments. (a): Infection of C3H mice with TBEV (first viral production) with 1 PFU/mouse, 10 PFU/mouse, 10² PFU/mouse. Blood samples were collected on different days from the infected mice, and mice still alive were sacrificed on day 11 p.i. to collect their brain. Samples were analyzed using real-time RT-PCR. (b): Infection of C3H mice with TBEV (second viral production) with 10² PFU/mouse, 10³ PFU/mouse. The infection was monitored by collecting blood samples on different days and mice still alive were sacrificed on day 15 p.i. to collect their organs. Acquisition of TBEV by ticks was evaluated by placing naive larvae on the backs of mice at different time points. Blood samples and ticks were analyzed using real-time RT-PCR, and organs were analyzed using digital PCR following RT and preamplification steps.