Monsoons could bring more mosquitoes |

Monsoons could bring more mosquitoes

Ryan Hoffman

Steps to prevent West Nile Virus:

Drain standing water around your house weekly. Remember to drain water from tires, cans, flowerpots, clogged rain gutters, rain barrels, toys and puddles.

Dusk and dawn are when mosquitoes are most active. Limit outdoor activities and take precautions to prevent mosquito bites during these times.

Deet is an effective ingredient to look for in insect repellents. Always follow label instructions carefully.

Dress in long sleeves and pants in areas where mosquitoes are active.

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The arrival of “monsoon season” across Colorado could bring an increased risk of West Nile virus, furthering the importance of safety precautions, especially in the western part of the state where the first diagnosed human case of the virus was confirmed this week.

Earlier this year, officials warned that above-normal amounts of rain in the spring would provide more breeding ground for mosquitoes, consequently increasing the risk of West Nile.

While conditions were relatively dry in June, forecasts indicate that the recent rains and thunderstorms are going to stick around for the remainder of the summer, said Chris Cuoco, a meteorologist based at the National Weather Service Grand Junction office.

All of Colorado is looking at a 33 percent chance for above average precipitation through September, according to the most recent three-month outlook.

“It appears like it’s going to be fairly consistent,” Cuoco said in reference to the monsoon season.

That could present several problems as it relates to local mosquito populations, said Steve Sheaffer, office manager for Colorado Mosquito Control in Garfield and Pitkin counties. Along with creating more habitat for the insect, rain can limit the opportunity to chemically treat areas with high populations.

On Wednesday, public health officials announced that Colorado’s first diagnosed human case of West Nile had been detected in Mesa County.

Mesa County Health Department is not at liberty to release the name or condition of the adult male, said Katie Goddeyne, communication specialist with the department. Goddeyne would not say where the man resides in Mesa County, but she confirmed that the individual reportedly had not recently left the county, meaning that he likely contracted the virus in Mesa County — despite the lack of any mosquito samples testing positive for the virus.

Last year 118 people contracted the virus in Colorado, with four of those cases occurring in Mesa County.

Garfield County has not had a confirmed case of West Nile since 2007, and unlike Mesa County, Garfield only tests mosquitoes for the disease when there are large numbers of the Culex tarsalis species, the main carrier of the virus, said Steve Anthony, county vegetation manager.

So far, trap counts across Garfield County — particularly in the west of the county, which historically has seen larger populations of mosquitoes — show slightly larger populations of the insect, including Culex tarsalis, Sheaffer said.

A trap count conducted June 30 to July 1 in Garfield County showed an overall increase of more than 5,400 mosquitoes, compared to a 2014 trap conducted between July 1 to July 2.

While the numbers are high, it is important to remember that the traps are located in areas with established populations, and the overall numbers include all species of mosquitoes, even the ones that do not carry West Nile, Sheaffer said, adding that the next several weeks will be a good indication of what the rest of summer looks like with regard to mosquitoes.

“It’s hard to say what it’s going to do in the next weeks,” he said.

In announcing the first diagnosed West Nile case, the Colorado Department of Public Health and Environment cited similar uncertainty, while urging people to take certain safety precautions.

“Although we can’t predict how much West Nile Virus activity will occur this summer, we know the virus is present, and that means people are at risk,” Jennifer House, state public health veterinarian, was quoted as saying in a press release.

So far, mosquitoes collected in Larimer and Denver counties have tested positive for the virus, but as the case in Mesa County shows, the virus can be present without the proof of a positive test.

“If (Garfield) County wanted to test every mosquito, I bet we’d find it,” Sheaffer said.

But that does not mean people should be reluctant to go out and enjoy the outdoors, Anthony said. People just need to take the appropriate precautions, including carrying insect repellent and wearing long-sleeved shirts and pants, especially around sunrise and sunset when Culex tarsalis is most active.

“I think people should continue to enjoy the outdoors and go camping, but just have those resources when they do it,” Anthony said.

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