Get the Facts

Placer County has over 30 different species of mosquitoes. Two of those 30 species are most responsible for transmitting West Nile virus to humans. To the untrained eye, it is hard to see the difference between mosquito species. We conduct surveillance throughout the county to keep track of mosquito species and mosquito-borne diseases. We alert the public when there is elevated risk of West Nile virus.

Prevent West Nile Virus

The easiest and best way to avoid WNV is to prevent mosquito bites.

  • When you are outdoors, use a EPA-registered repellent.
  • Many mosquitoes are most active at dusk and dawn. Be sure to use insect repellent and wear long sleeves and pants at these times or consider staying indoors during these hours.
  • Make sure you have good screens on your windows and doors to keep mosquitoes out.
  • Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets and barrels. Change the water in pet dishes and replace the water in bird baths every three days. Drill holes in tire swings so water drains out. Keep children’s wading pools empty and on their sides when they aren’t being used.

Read more about mosquito species in Placer County.

Read more about West Nile virus.

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