Carbon County reports first West Nile Virus case

Friday, August 31, 2018

Beartooth Billings Clinic Public Health and the Montana Department of Public Health and Human Services (DPHHS) confirmed the first human case of West Nile Virus (WNV) in Carbon County, Montana.  The male patient has been treated and released from a Billings hospital. Montana Department of Public Health and Human Services has also reported the first human death this year in Montana from West Nile Virus. The death was reported in an elderly Yellowstone County male who died after a brief stay in a Billings hospital. This is the first WNV associated death in the state since 2016.


As of Aug. 29, there were 19 confirmed human cases of WNV in Montana appearing in Carbon, Cascade, Lewis and Clark, McCone, Roosevelt, Toole, Valley, and Yellowstone counties. WNV season usually begins in July and ends in October in Montana.


The number of WNV human infections in Montana varies from year to year. Since 2003,

when WNV tracking began, Montana has had two years with more than two hundred cases reported: 2003–228 cases and 2007–201 cases. The average number of cases in Montana for the time period 2003-2017 is 36. In nine of the 15 year reporting period, there were less than 10 cases reported for the year. Last year, Montana had 11 human cases of WNV reported.


Only certain mosquitoes carry West Nile Virus and it is spread to people through bites. There is no vaccine to prevent WNV so the most effective way to prevent infection is to minimize the risk of mosquito bites by following the 4D’s. The 4D’s of West Nile Virus prevention are:

1. DEET: Use insect repellent containing DEET or picaridin. A solution with 25 percent

to 35 percent DEET is best but children ages 2-12 should use repellent with no more

than 10 percent DEET.

2 Drain: Empty standing water around your house to prevent mosquitoes breeding.

3 Dawn/Dusk: Mosquitoes are most active during dawn and dusk so stay inside during

these times or take precautions to prevent bites.

4. Dress: Protect yourself from bites by wearing long-sleeved shirts and pants while



About four out of five people infected with WNV have no symptoms. About one in five

infected people will experience mild symptoms that may include headache and muscle aches, joint pain, vomiting, diarrhea or a rash. Those cases usually require no treatment. Less than 1 in 100 people who become infected develop serious infections in or around the brain, also known as neuroinvasive disease. Life-threatening symptoms include headache, rash, high fever, stiff neck, mental confusion, and other symptoms. Individuals who develop any of these symptoms should see their healthcare provider immediately.


For more information about WNV, visit the Montana Department of Public Health and

Human Services website at: