Volume 16, Number 8—August 2010
Research
West Nile Virus Range Expansion into British Columbia
Table 1
Surveillance type | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 |
---|---|---|---|---|---|---|
Mosquito | ||||||
No. permanent trap locations | 145 | 189 | 148 | 155 | 98 | 91 |
No. mosquitoes collected |
52,657 |
198,228 |
394,047 |
242,215 |
202,460 |
181,942 |
Mosquito pools† | 2,980 | 6,631 | 2,329 | 2,568 | 1,873 | 1,469 |
Provincial | ||||||
No. Culex pipiens | 4.6 | 5.1 | 8.6 | 14.3 | 10.5 | 21.1 |
No. Cx. tarsalis | 0.8 | 1.9 | 4.8 | 3.5 | 1.4 | 11.8 |
Interior‡ | ||||||
No. Cx. pipiens | 12.6 | 8.9 | 9.5 | 8.2 | 4.7 | 7.6 (9.3) |
No. Cx. tarsalis | 11.0 | 12.0 | 22.5 | 10.1 | 2.9 | 33.1 (14.3) |
Fraser | ||||||
No. Cx. pipiens | 10.5 | 13.0 | 22.3 | 32.5 | 33.7 | 36.1 |
No. Cx. tarsalis |
6.9 |
4.9 |
7.7 |
7.1 |
7.0 |
15.1 |
Bird | ||||||
No. corvids sighted | 1,292 | 740 | 605 | 562 | 458 | 355 |
No. corvids submitted | 1,437 | 1,058 | 803 | 740 | 205 | 144 |
No. corvids positive |
0 |
0 |
0 |
0 |
0 |
0 |
Human | ||||||
No. tested | 481 | 755 | 239 | 805 | 530 | 340 |
No. positive§ | 0 | 0 | 0 | 19 (0) | 0 | 3 (2) |
*WNV, West Nile Virus.
†Values represent average trap catch. Provincial, average trap catch for all traps in British Columbia; Interior, average trap catch from the Interior Health Authority, which includes the southern Okanagan Valley (Figure 2); Fraser, average trap catch from the Fraser Health Authority (Figure 2).
‡Values represent average trap catch from all traps run in the southern Okanagan Valley in 2009, including 16 traps run in the area as part of a research project. Values within parentheses represent average trap catch without the research traps.
§No. human cases detected in British Columbia (no. cases acquired within British Columbia).
1Members of the British Columbia WNV Surveillance Team: Lucy Beck, Victoria Bowes, Elizabeth Brodkin, Steve Chong, Ken Christian, Dalton Cross, Murray Fyfe, Roland Guasparini, Paul Hasselback, Randy Heilbron, Mira Leslie, James Lu, Craig Nowakowski, Robert Parker, Tim Shum, Kevin Touchet, and Eric Young.