First human West Nile cases of 2019 confirmed in County

Delaney Allen

The Larimer County Department of Health and Environment has confirmed the first human cases of West Nile virus this year.

The cases were confirmed in both Fort Collins and Wellington. Residents are advised to protect themselves against being bitten by mosquitoes by using repellents and wearing clothes to minimize skin exposure when outdoors.


West Nile virus risk has been increasing throughout Larimer County, according to the press release from the LCDHE. The southeast part of Fort Collins is seeing increased risk of West Nile virus compared to the rest of the city. In June, trapping mosquitoes to monitor West Nile virus risk began in the county.

August and September are typically peak times for human West Nile virus cases in the area.

West Nile virus is a viral infection transmitted by infected Culex mosquitoes. Approximately 75% of people infected with West Nile virus do not show symptoms, while the other 25% will develop West Nile fever, characterized by fever, headaches, body aches, vomiting, diarrhea and fatigue.

In very severe cases, people infected with West Nile virus may develop a severe neuroinvasive form, which requires urgent hospitalization and can lead to critical illness, chronic disability or even death if left untreated.

In addition to wearing clothing that minimizes skin exposure and using mosquito repellent, the LCDHE advises people to avoid areas where mosquitoes feed and breed, such as marshy stagnant areas of water, and avoid exposure during peak Culex mosquito feeding times, which are dusk to dawn. They also advise draining any standing water in your yard or garden to minimize mosquito presence.

For more tips and information about West Nile virus and how you can prevent it, visit

Delaney Allen can be reached at or on Twitter @DelaneyAllen0.