West Nile virus Appearing Earlier in North Dakota This Summer

Mosquito larvae in a testing cup. (Photo provided by Cass County Vector Control via the North Dakota Monitor)

(North Dakota Monitor) – Cases of West Nile virus are springing up earlier this year in North Dakota due to wet weather creating prime mosquito breeding grounds, according to a state health official.

Fourteen human cases of West Nile virus, including three cases requiring hospitalization, have been reported in the state this summer. Cases have been identified in nine counties: Cass, Burleigh, Hettinger, McLean, Mercer, Richland, Morton, Kidder and Stutsman. Most cases have been reported since mid-July, with cases nearly doubling this week.

The virus is likely popping up earlier due to a rainier-than-normal summer creating more stagnant water pools, said Amanda Bakken, West Nile virus surveillance coordinator for the Department of Health and Human Services. The virus typically begins spreading in late August or September, she said. “I think we are on track to certainly have more cases than last year,” she said.

In 2024, North Dakota reported 38 human cases of West Nile virus, down from 58 in 2023, according to state data.