Despite rising West Nile virus infections in Larimer County, but many oppose mosquito spraying

FORT COLLINS, Colo. - Larimer County health officials aren't allowing residents to opt out of spraying to kill mosquitoes, saying 30 people have been infected with West Nile virus so far this year and those numbers are expected to climb.

Yet, residents were lining up at the Fort Collins City Council meeting Tuesday night, many objecting to the spraying of their neighborhoods with the pesticide Permethrin. Residents raised concerns about the safety and effectiveness of the spraying program.

Some held up signs with skull and crossbones and the words "No Spray!"

"I would like you to continue to research better ways for mosquito control," Sonya Krueger, a Fort Collins resident told city council members.

County health officials say the West Nile infection threat -- the worst outbreak in a decade -- is too great to allow people to opt out of spraying near their homes, which officials normally allow.

As of Monday, 30 county residents have been confirmed to have been infected with the West Nile virus, health officials said. Eight of those people having the most serious “neuroinvasive” form, which includes meningitis, encephalitis, and paralysis. For every neuroinvasive case, it is estimated that 150 to 250 people have been infected, and 40 to 60 have become ill, officials said.

Two additional West Nile infections were identified in Fort Collins blood donors who appear to be healthy so far, health officials said. Screening blood for West Nile virus catches most -- but  not all --infected blood donations, and those units are discarded. A Colorado man died in 2012 from a blood donation that was infected with West Nile virus.

Officials began spraying the entire city of Fort Collins last week.

Over several nights, trucks are applying the pesticide in fine mist, spraying from dusk until 2 a.m.

"The overall goal of this policy is to reduce the risk of human West Nile virus infection while limiting adverse human health and environmental impacts," officials said on the city's website.

"We expect the number of human cases to continue rise over the next few weeks despite the recent spraying," said Dr. Adrienne LeBailly, director of the Larimer County Health Department.  "We believe all the reported illnesses so far have occurred in individuals who were bitten in July, when the number of infected Culex mosquito was beginning to rise rapidly. These cases are only being reported to public health now. People infected in August will be reported to us in the coming weeks and months." 

City officials hope the arrival of cooler weather this fall will drive away mosquitoes until next spring.

"Tonight, after the (pesticide spraying) application is completed, hopefully mother nature helps us out and knocks the mosquito population down with the coming of fall," Mike Calhoon, a Fort Collins Parks supervisor told 7NEWS at the council meeting.

Residents are warned to stay indoors and keep doors and windows closed for 30 to 60 minutes after spraying occurs. The city recommends that residents bring pets indoors as well. The city also suggests residents minimize pesticide exposure by covering organic gardens, ponds, and water features with a sheet or tarp.

West Nile virus is a disease carried by infected Culex mosquitoes that can cause mild to severe illness.  About 75 percent of people who are infected have no symptoms, health officials said. About 25 percent will develop West Nile Fever.  Less than 1 percent develop the most severe neuroinvasive from, which can lead to hospitalization, critical illness, chronic disability or even death.

To protect yourself from mosquito bites and West Nile virus, the Larimer County Health Department recommends the following precautions:

--Use a mosquito repellent that has been proven to be effective against West Nile Virus-carrying mosquitoes. Those containing DEET, Picaridin, Oil of Lemon Eucalyptus (with active ingredient PMD, or p-menthane diol) or IR3535 are good choices.

--Keep exposed skin covered or use a repellent when out at prime Culex mosquito-biting hours, between dusk and dawn.

--Drain standing water in your yard or in your garden.

--Add mosquito-eating minnows to or a mosquito "dunk" to ornamental ponds that feature still water.

--Use netting over baby carriers and strollers

--Keep window screens repaired.

For more tips on what you can do to prevent West Nile virus, or on repellent use, visit: or call 498-6700.

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