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Calm before the swarm: Preparing for summer's mosquito season

SALT LAKE CITY — As temperatures are warming up, mosquitoes are beginning to make their annoying debut across Utah.

"These next two weeks we are going to be seeing a ton of increases in mosquitoes because of flooding in the marsh," said Gary Hatch, manager of Davis County's Mosquito Abatement District.

The recent May rains have increased standing water in the swampy areas of Utah and in people's backyards — causing an increase in surfaces that mosquitoes breed and lay eggs in.

As standing water remains undisturbed, the period when mosquitoes carrying the West Nile Virus make an appearance in Utah draws nearer — down to a few weeks.

However, as these shallow standing water surfaces evaporate during the warmer weather, fewer eggs will hatch and some of the storm-related larvae will die.

"We have been testing for the disease, but we haven't seen any carrying West Nile virus" in Salt Lake County, said Sammie Dickson, from the Salt Lake Mosquito Abatement District.

Mosquitoes that carry the virus usually appear after the first wave of Utah mosquitoes arrives, because the breed develops in the water for a longer period and cannot live during the colder nights, according to Dickson.

"The ones that bite during the day do not transmit the disease," he said. Besides the discomfort of the bite, "people don't have to worry about those."

West Nile mosquitoes bite from dusk to dawn, but not all mosquitoes biting at this time carry the disease.

"You can't tell the difference, actually. The mosquitoes who carry West Nile do not look very different, and neither do their bites," said Utah Department of Health spokesman Tom Hudachko.

The virus itself originated in Africa during the 1930s and was not documented in Utah until 2003, according to the Utah Department of Health.

"Cases in general have really declined. They have dropped almost entirely off since 2009" in Utah, Hudachko said.

Post-2009, the number of people who have been reported with advanced symptoms of West Nile virus has remained in single digits in the state of Utah. Since the disease's introduction into Utah 12 years ago, nine people died because of the virus. The last death occurred in 2012, which was the first West Nile death in Utah in four years.

"Most people who get infected with West Nile will never develop symptoms or realize they have been bitten by a mosquito that carries the disease," said Hudachko. "Twenty percent will develop flu-like symptoms: fever, body ache, sometimes a rash."

The worst year for the virus, so far, in Utah occurred during 2006 when 158 Utahns were infected with West Nile Virus and displayed advanced neuroinvasive symptoms, rather than the more common version with mild flu-like symptoms.

Not only is physical manifestation of the disease uncommon, West Nile can only be contracted by mosquito bite. It cannot be transferred from person to person, nor from other animals to people, according to Hudachko.

"DEET is the best way to prevent yourself from being bitten by mosquitoes that are carrying West Nile, and it is safe for people to use," explained Hudachko, who also added that long-sleeve shirts and pants can also prevent bites.

While everyone should participate in mosquito prevention and protect themselves from being bitten, like other diseases, young people, pregnant women and older people should take extra precautions because they are more susceptible to the advanced manifestations of the disease.

Abatement teams in multiple Utah districts have been working to combat the insects. Teams began treating neighborhoods in April and May, but are slightly behind because of recent rains, according to Hatch.

"It's not that we don't want to spray the neighborhood, we would love to," he said about increasing the amount of treatment done in earlier months. "By the time it's late enough in the evening so we can get into a neighborhood and spray, the mosquitoes aren't out to spray."

The minimum temperature that abatement teams spray for mosquitoes is about 50 degrees, but 53 to 55 degrees is preferred.

"They need to be up and moving about so we can spray them," explained Hatch.

Fortunately, there are several steps that Utahns can take to help curtail the large number of mosquitoes predicted to arrive within the next two weeks.

The most important is removing unnecessary standing water. Those who may chose to use standing water for decor or out of necessity in their yards, such as bird baths and pet water bowls, are advised to change this water every seven days, according to Hatch.

Those who have ornamental ponds can also call their abatement district to obtain fish that will eat mosquito larva.

Hatch also recommends that Utahns keep their vegetation cut back and not over-water their yards.

"They are looking for a blood meal and a place to rest," said Hatch about the mosquitoes, claiming that the insects are attracted to the humidity found within vegetation.

This advice also extends to unwanted vegetation that has already been removed. A common breeding ground for mosquitoes that Utahns often neglect is their weeding buckets.

"A lot of people like to have a bucket to keep outside and put weeds in, but then water gets in it when it rains," Hatch said.

As Utahns participate in preventative measures now, the fewer mosquitoes they will have to battle in the upcoming weeks, and later in the summer.

Email: chansen@deseretnews.com