Laramie’s mosquito control crew started spraying in parks and other public places, or fogging, last week to combat the increasing numbers of mosquitos.
Some species of mosquitos can carry—and transmit to humans—West Nile Virus (WNV), an arthropod-borne virus that can give humans the lethal disease; however, the threat of a WNV outbreak in Laramie is minimal.
“We’re at risk level one,” Keith Wardlaw, Laramie mosquito control crew supervisor, said. “We see extremely low numbers of vector mosquitos but there’s still a slight risk that you could be bitten.”
Laramie resident Kady Barker said the mosquitos this year didn’t particularly bother her.
“They like other people more than they like me,” she said. “But they’re still annoying. I still get bitten.”
The fear of WNV does not keep Barker from enjoying the park.
“People in my family have gotten it before so I’m concerned a little but I’m not concerned about getting it personally,” she said.
As defined by the CDC’s guidelines for surveillance, prevention and control of WNV, risk level zero represents no possibility of a human outbreak, such as the case during the mosquito-free winter; risk level one is a low possibility; risk level two is a high possibility; and risk level three indicates an outbreak in progress.
“The objective of a phased response to WNV surveillance data is to implement public health interventions appropriate to the level of WNV risk in a community,” according to the CDC guidelines.
WNV is less dangerous than other diseases. Only 20 to 30 percent of people infected show any symptoms. The people who do exhibit symptoms can get headaches, vomiting, diarrhea and other symptoms related to fevers, but generally recover in a day or two. Few people actually suffer severe symptoms or die from WNV, according to the CDC.
The city’s mosquito control crew monitors the local mosquito population for both vector – potentially virus-carrying species – and nuisance mosquitos.
“We have thresholds for nuisance mosquitos that are much higher than vector mosquitos,” Wardlaw said. “We are currently fogging for nuisance mosquitos.”
The mosquito control crew supervisor also said vector mosquitos, that have different life cycles than nuisance mosquitos mean they emerge later in the season, would persist possibly until early October. Nuisance mosquitos will likely die out by mid-august, but the larvicide used in fogging for both sets of species is the same.
“It’s lethal to all different varieties of mosquitos,” Wardlaw said. “We do both.”
The fogging, which takes place at night, will continue throughout the summer, for as long as mosquitos meet the control crew’s thresholds.
“It’s always a little bit of a gamble,” Wardlaw said. “The weather plays a part.”
