Four more human cases of West Nile virus were reported in North Dakota in the past week, including two in Morton County and one in Burleigh. The North Dakota Department of Health released weekly statistics on West Nile virus reports Wednesday.

A person in Burleigh County, two people in Morton County and a person in Dickey County are the latest reported cases. This brings the total number of human West Nile virus cases in the state this year to five. A Richland County man was the first reported case July 25.

"People still need to protect themselves," West Nile virus surveillance coordinator Michelle Feist said.

The warm, dry weather has kept mosquito numbers down, but the primary carrier of the virus prefers this type of weather, Feist said.

The culex tarsalis mosquito likes warmer temperatures, unlike the nuisance mosquitoes that like cooler weather.

As a prevention against more West Nile cases in humans, Feist recommends using insect repellent, even on the outside of clothing. Ridding yards of shallow, stagnant water also helps keep the mosquitoes at bay.

The people who were reported with West Nile virus are all males. One is 10 to 19 years old, one is in his 40s and three are in their 50s, Feist said. She did not have the age of a person by county.

Most people who are infected by West Nile virus do not show symptoms. For those who do show symptoms, they have fever, headache and nausea for a few days. The most severe cases can cause encephalitis or meningitis, which can be fatal.

August was the peak of human West Nile cases in 2005. There were 89 reported cases and no fatalities. The first case this year year happened about the same time as last year, Feist said.

For more information about West Nile virus, visit www.ndwnv.com.

(Reach reporter Sara Kincaid at 250-8251 or sara.kincaid@;bismarcktribune.com.)