West Nile virus
Surveillance and alert levels
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Current Alert Level
Remote risk of human outbreak
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Case Counts
Updated on Tuesdays at 2pm, July - November
Surveillance through week 34 (ending 08/23/08)
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2008 West Nile virus (WNV) activity in King County
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Exposed in King County
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Exposed elsewhere
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Humans
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West Nile fever
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0
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0
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West Nile neuroinvasive disease
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0
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0
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Other West Nile infection (positive tests with mild or no symptoms)
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0
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1
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Deaths
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0
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0
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Total
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0
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0
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Non-human WNV surveillance
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Birds
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Horses
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0
1,227 dead birds reported, 39 collected for testing
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0
320 trapping events,
166 pools tested*
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*A mosquito pool is a group of 10 to 50 female mosquitoes of the same species collected from one trap during a single trapping event.
WNV surveillance in Seattle & King County
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Other WNV surveillance information
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West Nile virus alert level definitions
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Note:
King
County
alert levels are determined based on events occurring within
King
County
. As a result, our current alert level may differ from that of the state or other local health jurisdictions.
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Alert Level
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Description
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No risk of human outbreak
Winter season; little or no mosquito activity.
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Remote risk of human outbreak
No West Nile virus positive birds or mosquitoes and no cases in horses or people in King County in the current calendar year.
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Low risk of human outbreak
Areas of King County with limited West Nile virus activity in birds and/or mosquitoes but no positives prior to August 1.
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Moderate risk of human outbreak
First West Nile virus positive birds or mosquitoes found before August 1
OR a confirmed horse or human case
OR sustained West Nile virus activity in birds or mosquitoes in the absence of horse or human cases.
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High risk of human outbreak
Combinations of the following indicators:
| a) |
high dead bird densities starting in early summer; |
| b) |
sustained high mosquito infection rates; |
| c) |
multiple positive mosquito species; |
| d) |
increasing number of infected horses or other mammals; |
| e) |
a human case with high levels of bird, mosquito or horse infections; |
| f) |
areas with early West Nile virus activity that experienced epidemic conditions in past years. |
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Human outbreak in progress
Multiple confirmed human cases with conditions favoring continued transmission to people (e.g., persistent high infection rates in mosquitoes, continued bird deaths due to West Nile virus)
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| Report dead birds
Help us fight West Nile virus! If you see a dead bird in King County, report it on our online form or call 206-205-4394 to tell us about it.
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