Volume 10, Number 8—August 2004
Research
Acute Encephalitis Hospitalizations, California, 1990–1999: Unrecognized Arboviral Encephalitis?
Table 4
SLEV- and WEEV-positive Culex tarsalis pools in selected California counties, 1991–1999a,b
Year |
No. of virus-positive mosquito pools (no. pools testedc |
|||
---|---|---|---|---|
Sacramento-Yolo | Sutter-Yuba | Imperial-Riverside | ||
WEEV |
WEEV |
WEEV |
SLEV |
|
1991 |
0 |
0 |
73 |
44 |
1992 |
0 |
0 |
20 |
10 |
1993 |
81 |
31 |
13 |
15 |
1994 |
4 |
0 |
1 |
7 |
1995 |
2 |
1 |
0 |
0 |
1996 |
9 |
2 |
0 |
1 |
1997 |
10 |
14 |
0 |
0 |
1998 |
0 (187) |
0 (172) |
11 (968) |
1 (968) |
1999 | 0 (548) | 0 (232) | 0 (918) | 0 (918) |
aSLEV, St. Louis encephalitis virus; WEEV, Western equine encephalitis virus.
bSources: Hui et al., 1999 (1991–1997); CDHS, Vector-Borne Disease Section, Annual Reports (1998 & 1999).
cThe number of mosquito pools tested (denominator) was only available for 1998 and 1999.