Table 1.

Replication and lethality in chickens of the H5N6 viruses after intranasal infection^a.

Strains	Titer (log10 EID50)	Virus replication on 3 days post-inoculation (DPI; log10 EID50/0.1 ml)b in						Manifestations of chickens
		Heart	Liver	Spleen	Lung	Kidney	Brain	No. D/S/totalc
018	8.63	4.00 ± 0.00	5.92 ± 0.51	5.25 ± 0.29	6.75 ± 0.87	6.58 ± 0.68	5.25 ± 0.13	10/10/10
021	8.54	3.92 ± 0.01	5.5 ± 0.67	5.08 ± 0.26	6.17 ± 0.35	5.92 ± 0.51	5.33 ± 0.22	10/10/10

^aSix-week-old SPF chickens were inoculated intranasally (i.n.) with 10⁶ EID₅₀ of 018 virus or 10⁶ EID₅₀ of 021 virus in a volume of 100 μl, respectively; three chickens in each group were euthanized on 3 DPI, and virus titers were measured in samples of heart, liver, spleen, lung, kidney, and brain in the chicken embryo. ^bFor statistical analysis, a value of 1.5 was assigned if the virus was not detected from the undiluted sample in three embryonated hen eggs. Virus titers were expressed as means standard deviation in log₁₀ EID₅₀/0.1 ml of tissue. ^cNo. D/S/total showed the number of dead (D) and sick (S) as well as the total number of chickens during the observation period. Birds that showed disease signs such as depression and ruffled feathers, but recovered at the end of the observation, were considered to be sick animals.