Survival of influenza PR8 on porous, non-porous, metallic and wood surfaces.

*P = porous; NP = non-porous; M = metallic; NM = non-metallic.Values plotted are the log10 reduction in plaque titre with respect to the input inoculum and are the mean of 2–3 replicates. Under the assay conditions, 100% recovery would have resulted in a titre of 3×105 PFU/ml and the lower limit of detection was 20 PFU/ml.†Plastic control = virus applied directly to the tissue culture dish surface.