TABLE 1.

Method of WNV infection does not affect morbidity or mortality in mice

Mouse strain	Mode of infectiona	No. infectedb/no. exposed	No. sickc/no. infected	No. diedc/no. infected	Avg day of disease onset (SD)d	Avg survival time, days (SD)e
B6	Mosquito	11/12	2/11	1/11	7.0 (0.0)	12.0 (NAf)
	Needle	12/12	5/12	3/12	6.8 (0.8)	10.7 (2.3)
C3H	Mosquito	15/16	14/15	14/15	6.6 (0.8)	7.5 (1.2)
	Needle	16/16	16/16	13/16	7.4 (1.5)	8.2 (1.6)

^aMice were infected by the bite of a single WNV-infected C. tarsalis mosquito or by s.c. needle inoculation with 10⁵ PFU of WNV-BHK in the left rear footpad. After feeding, all mosquitoes were confirmed to be infected by plaque assay.

^bNumber of infected mice includes mice that died of WNV disease and mice that seroconverted to WNV at >21 dpi.

^cMice were monitored for weight loss and clinical signs and were euthanized upon severe disease. No morbidity or mortality was observed in control mice inoculated with diluent or fed upon by uninfected mosquitoes.

^dAverage day of disease onset in days, calculated for mice that were sick only.

^eAverage survival time in days, calculated for mice that died only.

^fNA, not applicable.