West Nile (Non)Prevention in Fort Collins

CareyMug
Jesse Carey

In the sweltering summer months in Colorado, in the waters left by river overflow or the fetid outflow areas in the croplands, mosquitoes hatch, grow, propagate and die, the standard circle-of-life deal. Which would be fine, if the mosquito populations were not vectors for disease, including ancient scourges like malaria and yellow fever, and more pertinent to this column, West Nile virus.

Unfortunately, the Fort Collins City Council has seemingly decided that mosquitos are just a mild inconvenience, and are pursuing a policy of reckless naivete at best, and a sort of callous indifference at worst, putting their own political health before public health.

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First, some facts: West Nile is spread by a specific genus of mosquito, Culex. Culex Mosquitoes are endemic to Colorado, and emerge in mid-to-late June. One female Culex mosquito can lay many hundreds of eggs in one go. In a wet year, like the one Fort Collins is currently having, the mosquito populations will explode; and with it, West Nile incidence.

Though West Nile is largely benign, one out of five people infected with the virus will get sick, and about 1 percent of these cases can result in encephalitis, an often lethal development. At highest risk are the young, the old and the immunocompromised.

Through August 21st, about a third of the mosquito traps set around Fort Collins have produced positive results for West Nile virus. It must be said here that Fort Collins does employ some forms of mosquito control, in the form of larviciding. Larviciding is a low-impact method of control that destroys only mosquito larva. In wet years, however larviciding is not enough, as the amount of standing water becomes too much to effectively spread the larvicide.

Spraying to kill the adults becomes one of the only effective ways to keep the levels of West Nile low. Since 2003, Fort Collins has mandated the spray threshold would be the emergence of two human cases of West Nile. Before that threshold is met, Fort Collins will not spray for mosquitos.

The spray policy that Fort Collins has implemented is a terrible decision. West Nile has a fairly long incubation period — by the time human cases appear, it is likely that the spread of West Nile has already occurred. In other words, waiting for cases to manifest is not prevention at all.

What is worse is that Fort Collins’s City Council ignored the advice of mosquito experts and voted to keep the threshold limit at two human cases, even though it was apparent that West Nile was all over the city.

The reason for this hardheadedness stems from a fear about voter backlash — many residents lack a basic understanding of the mosquito life cycle, West Nile prevention, and even the application and spray rate for the adulticidal spray. These fears of political health may have a serious impact on the public health of Fort Collins.

County officials did the right thing when faced with this hardheadedness: they overrode the city council and mandated the southeast corner of Fort Collins be sprayed. There was a predictable outcry at news of this decision, but in this instance, it is more about the greater public health than the opinions of a mistaken few who seem to believe that Fort Collins is somehow immune to West Nile.

If Fort Collins does not want to spray for adult mosquitos all summer long, then that is more than all right, as the spray does have some environmental drawbacks. Bees, in particular, are vulnerable to the spray, and the spray is a mild carcinogen. The fog is sprayed at dusk to minimize these drawbacks. Nevertheless, when faced with an overwhelming amount of a potentially malignant virus, a step away from hardheadedness and toward proactivity would be simply fantastic.

The citizens who criticize the county would do well to educate themselves and look instead at lobbying their criticisms at a local government that would leave them so exposed.

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Collegian columnist Jesse Carey can be reached at letters@collegian.com.