Several counties in Montana are observing an increase in West Nile Virus cases, leading state and local health officials to appeal to Montanans to safeguard themselves from mosquito bites.
Seven residents in McCone, Richland, Dawson, Rosebud and Yellowstone counties have tested positive for the virus this year, according to surveillance data from the Department of Public Health and Human Services last updated Friday. The virus has also been detected in mosquito pools and in horses, bringing the total number of counties with recorded West Nile Virus activity so far in 2023 to seventeen.
According to the communications coordinator of Riverstone Health, Pat Zeller, three individuals residing in Yellowstone County have been infected. Among them, two were hospitalized due to severe brain and neurological symptoms. Zeller mentioned that one person has been discharged, while the other individual is still receiving treatment in a hospital located in Billings.
According to state and local health officials, a significant number of individuals infected with the virus do not show any symptoms. However, approximately 1 in 5 individuals may encounter a fever that persists for three to six days along with other mild symptoms.
According to the state health department, severe cases of West Nile Virus, although rare, can potentially result in encephalitis or meningitis. These conditions involve the swelling of the brain or the protective membranes around the brain and spinal cord. Some of the symptoms that may arise from this can include disorientation, coma, tremors, convulsions, vision loss, numbness, and paralysis. These symptoms can persist for weeks and may even become permanent.
West Nile Virus is most commonly spread through bites from an infected mosquito. There is no vaccine to protect against the virus available for humans.
In July, health officials in Montana reported the first detection of the virus in Blaine County for the year. Although no cases of West Nile Virus were reported among humans in 2022, the Montana state health department recorded up to 51 cases in a single summer back in 2018. West Nile Virus was initially identified in Montana in 2002.
Devon Cozart, a vectorborne disease epidemiologist with the state health department, stated in a July announcement that a significant number of active Culex species mosquitoes, known for carrying and transmitting WNV, have been detected during this year’s mosquito surveillance. Cozart emphasized that protecting oneself from mosquito bites is the most effective strategy to prevent mosquito-borne diseases, including WNV.
In addition to using bug repellent that specifically wards against mosquitos with the ingredients of DEET or picaridin, health officials recommend avoiding the outdoors at dawn and dusk and wearing tightly woven, loose-fitting clothing to protect against mosquito bites. Draining standing water, which can give mosquitos more places to lay their eggs, is also commonly recommended as a preventative measure.
To ensure adequate protection, it is necessary for individuals to wear protective clothing that covers their arms, legs, and feet. In the case of infants and young children, mosquito netting that covers strollers and baby carriers can effectively safeguard them.
There have been no reported fatalities due to West Nile Virus in the state this year. However, in 2016, Montana documented two deaths related to the virus, and one more in 2018. The Centers for Disease Control and Prevention reported a total of 90 deaths across the country last year that were attributed to West Nile Virus.
This story was updated on August 30 to correct a detail about a patient in Yellowstone County. Local health officials said the person was hospitalized in Billings, not at Billings Clinic.
