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West Nile Virus Activity 2017

May contain: animal, bird, and crow

West Nile virus Facts

  1. West Nile virus is the most common mosquito-borne disease that affect residents in Los Angeles County
  2. Public health agencies detect West Nile virus every year in L.A. County. This means the virus is found naturally in our city environments, which means it's endemic.
  3. Our agency uses routine traps to colect samples of mosquitoes. The mosquito samples are tested for a mosquito-borne diseases, such as West Nile virus. In addition, dead birds, which can carry West Nile virus, are submitted for testing.

Our agency reports data related to mosquitoes. Human cases are reported by the L.A. County Department of Public Health and Pasadena Health Department.


2017 West Nile Virus Activity

West Nile Virus Positive Mosquito Samples

A sample is a random collection of 10-50 mosquitoes from a trap. Positive mosquito samples from routine and randomized trapping provide insight into of the spread of West Nile virus.

City/CommunityNumber of WNV+ Mosquito Samples
Alhambra10
Arcadia15
Azusa10
Bradbury1
Claremont11
Covina17
Duarte4
El Monte6
Glendora4
Irwindale3
La Puente9
La Verne6
Monrovia1
Monterey Park5
Pasadena
Pomona4
Rosemead3
San Dimas10
San Gabriel15
Sierra Mare1
Temple City2
Walnut3
West Covina13
TOTAL154

West Nile Virus Positive Dead Birds

People report dead birds they observe in their community. Positive dead birds are an indication West Nile virus is widespread in the region.

Dead bird data is stored with California Department of Public Health. You can access the data HERE.

Wonder how your community compares to the rest of Southern California?