H5N1 infectivity and viral genetic loads in lung and brain.

NOTE. Viral infectivity and relative viral genetic loads are expressed as log10 TCID50/g and log10 U per 20 ng of extracted RNA (geometric mean±s.d. of triplicate reactions), respectively, where 1 unit (1 U) of viral RNA is arbitrarily defined as the number of RNA molecules which, when reverse transcribed and subjected to real-time PCR, produced a CT value of 38.*Day post-challenge.†Undetectable (3.2 TCID50/g (infectivity) or