• Bug bites can be more than an annoying itch.
  • Weather conditions are the number one predictor of mosquito populations.
  • Between 2013-2018 there have been 20 human cases of West Nile in Mesa County.


2013 2014 2015 2016 2017 2018 Total
Mesa 9 7 2 0 0 2 20
Delta 14 3 0 0 1 8 26
Montrose 2 1 0 0 1 8 12
Garfield 0 0 0 0 0 1 1


  • The first U.S. case of West Nile was detected in 1999 and the first Colorado case was detected in 2002.
  • West Nile and other illnesses can be transmitted through mosquitos.
    • West Nile can cause a potentially fatal neurological disease in humans.
    • The virus can also cause severe disease and death in horses.
    • There is a vaccine for horses, but not yet for humans. Your best protection comes from preventive measures.
  • Grand River Mosquito Control District has traps across Western Colorado to monitor mosquito populations. So far this year, the number of Culex mosquitos (the type that can carry West Nile) isn’t significantly different than in years past, but the numbers are growing, usually peaking in early August.
  • Rain followed by sudden warm weather creates perfect conditions for mosquitos to lay eggs.
  • Standing pools of water are a perfect breeding ground for mosquitos.
    • Female mosquitos can lay up to 300 eggs at a time. Usually, the eggs are in a cluster that can hatch in as little as an inch of standing water.
  • Simple preventive measures can protect you and your family against these diseases.
    • Wear long pants and shirts.
    • Use insect repellent with DEET, Picaridin, IR3535, or oil of lemon eucalyptus.
    • Repair holes on screen windows or doors to keep mosquitos outside.
    • Drain standing water around your home.