Table 1. Surveillance data for southern West Nile virus foci and the rest of California, January 1–November 1, 2003^a.

Surveillance data	Research areas
	Imperial	Coachella	LA	Remaining agencies	Total
Human cases	1	0	0	1	2
Horse cases	0	0	0	1	1
Mosquito pools	238	1,414	1,663	6,416	9,731
Culex tarsalis	150	948	121	3,176	4,395
WNV pos	16	10	0	0	26
SLEV pos	1	3	0	0	4
WEEV pos	0	0	0	1	1
Cx. pipiens complex	0	299	1,036	1,170	2,505
WNV pos	0	0	6	0	6
Othersb	88	167	506	2,070	2,831
Sentinel chickens	6	10	5	191	212
WNV pos	51	18	0	0	69
SLEV pos	3	2	0	8	13
WEEV pos	0	0	0	0	0
Dead birds reported	23	15	1,218	6,294	7,550
Tested	6	5	256	1,118	1,385
WNV pos	0	0	38	21	59
Wild bird sera	0	3,178	1,452	4,502	9,132
WNV pos		51	0	0	51
WEEV pos		2	0	0	2

^aLA, Los Angeles; WNV, West Nile virus; SLEV, St. Louis encephalitis virus; WEEV, western equine encephalitis virus; pos, positive.
^bOther mosquitoes tested: Anopheles franciscanus, An. hermsi, Ae. vexans, Culiseta inornata, Cs. incidens, Cx. erythrothorax, Cx. erraticus, Cx. stigmatosoma, Oc. sierrensis, Oc. dorsalis, Oc. melanimon, Oc. taeniorhynchus, Psorophora columbiae.