Table 2. Mice mortality and virulence of West Nile virus in vivo of 5- to 6-week-old Swiss mice observed for 21 days.

Strain	Lineage	Viral dose (PFU)	dead/total (mice)	%Mortality	ASTa(days)
ArD76986	1	100	0/12	0	-
		1000	6/12	50	16.4
		10000	5/12	42	16.7
B956	2	100	1/12	8	19.7
		1000	7/12	58	14.3
		10000	3/12	25	18.7
ArD96655	7	100	8/8	100	5.5
		1000	12/12	100	10.8
		10000	12/12	100	9.2
ArD94343	8	100	0/12	0	-
		1000	0/12	0	-
		10000	1/12	8	19.7

^a AST (Average survival time)