Replication of 2009 A(H1N1) influenza viruses and a seasonal H1N1 virus in ferrets^a.

aThree ferrets were inoculated i.n. with 107 TCID50 of the indicated virus, respectively. These animals were euthanized at 3 and 7 days after inoculation. Virus titers in nasal turbinates, trachea, lungs and brain tissue were determined by means of end-point titration in MDCK cells. No virus was detected in liver, spleen, and kidney tissue for either virus and was thus not included in the table. Geometric mean titer ± SD is indicated. bLower limit of detection is 10TCID50/g of tissue.