Missoula health officials say West Nile likely this summer; urge bird reports, horse vaccination and mosquito control

Missoula health officials told a public forum that West Nile virus is likely to reach Missoula this summer and outlined surveillance and prevention steps for residents and animal owners.

“We're leaning strongly that it's gonna be in Missoula this summer,” said Greg Oliver of the Missoula health department as presenters described how migrating birds, infected mosquitoes and local mosquito habitat drive spread.

Health officials emphasized that birds are the reservoir and mosquitoes the vector for West Nile virus. Jim Carlson, environmental health director, said humans and horses are “dead end[s] in terms of transmission of the disease,” meaning infected people and horses do not generally pass the virus back to mosquitoes. Brent Good, the department’s lead epidemiologist, described national and state surveillance patterns showing human case onset typically peaks in late August and September.

The forum covered animal and human risks and practical prevention measures. Veterinarian Dr. Roulette Prine said horses are commonly affected because they spend more time outdoors; Montana had 134 confirmed equine cases last year with 38 horses dying or…