The Cascade County Mosquito Control Supervisor says it was one of the quietest years for the West Nile virus in the area in recent years.
Only four mosquito pools tested positive and no cases were found in humans or horses.
Mosquito control says the breed of mosquito that carries the virus was less prevalent, and a cooler summer certainly helped.
Ryan Arkoudas, mosquito control supervisor, noted, "Temperature during July and August was the biggest reason we didn't have the West Nile cases."
The state reports there were six confirmed human cases this year and 14 horse cases.
Last year five human cases were reported in the state.
In 2007, more than 200 people were infected and four people died from the virus.
The county mosquito supervisor warns every season is different, adding that a lot can depend also on the timing of rainfall and the flow of the Missouri River.