North Idaho saw its first case of locally acquired West Nile Virus this week after a Kootenai County resident tested positive for the virus.
The Panhandle Health District said the resident, who is over the age of 50, is hospitalized and recovering. They believe the patient acquired the virus through local mosquitoes – the first time such an event has been reported in North Idaho.
“While several cases of West Nile Virus are reported each summer, all previously reported human cases have been directly related to travel outside the region,” said Dr. Dave Hylsky, an epidemiologist at the health district, in a news release. “It’s imperative that people take extra precautions to protect themselves.”
The last case of a human testing positive for West Nile in Kootenai County was in 2007. A horse tested positive in 2016.
Last year, three people in Spokane County tested positive for the virus. Before that, there hadn’t been a case of West Nile in Spokane County since 2009, though one mosquito sample did test positive for the virus in 2013, according to Sandy Phillips, technical adviser for the Living Environment program for the Spokane Regional Health District.
There have been no reported cases in Spokane County this year, she said. But the type of mosquitoes that carry West Nile do live in the area, so residents should take precautions to avoid mosquito bites.
A total of 11 Idaho counties have reported West Nile since the end of May, the Idaho Department of Health and Welfare said. This is Idaho’s first confirmed case of a human being infected in 2017.
“West Nile activity has ramped up significantly during the last few weeks, so people are strongly encouraged to fight the bite of mosquitoes to protect themselves and their families,” said Leslie Tengelsen, a state public health veterinarian, in an Idaho Department of Health news release. “This is a good warning for all of us to take protective measures, including wearing insect repellent and reducing mosquito habitat, such as standing water, around our gardens and homes.”
The Panhandle Health District recommends people take the following steps to prevent mosquito bites: maintain window and door screens; remove standing water from buckets, pools or old tires; use nets or fans over outdoor eating areas; avoid being outside at dusk or dawn when mosquitoes are most active; wear light-colored, long-sleeved shirts and long pants when outside; and apply insect repellent that contains the active ingredient DEET, or other EPA-approved products.
West Nile can be transmitted to humans, horses and other animals by infected mosquitoes after they come in contact with infected birds – the primary hosts of the virus, the health district said.
Most people bitten by West Nile-infected mosquitoes may experience mild flu-like symptoms or no symptoms at all. Those who do develop symptoms may experience fever, nausea, headaches and muscle aches anywhere from 3 to 14 days after the insect bite, the health district said.
In rare cases, severe illness, including meningitis, encephalitis, or even death can occur. The health district warned people older than 50, or those with weakened immune systems, are at a higher risk for severe illness from West Nile virus.
Last year, nine human cases of West Nile infection were reported from 15 counties, with no deaths, the state health department said. In 2006, Idaho led the nation for West Nile illnesses, with almost 1,000 infections that contributed to 23 deaths.
Reporter Abby Lynes contributed to this story.