Viral RNA copies and NS1 production.

Biological properties of imported (A and C) and local isolates (B and D). Viral loads are expressed as log copy/µL (A and B), points are mean values of two independent experiments. The SD are not seen in some of the points because they fall inside the symbol. NS1 production is expressed as absorbance at 450 nm/cut-off value (SR = sample ratio) (C and D). Dpi: days post-infection.