15 new cases have been reported recently as the season hits its peak over the next two weeks.
"Of those infected so far in South Dakota, five people have the severe, neuro-invasive form of the disease, which can cause paralysis, brain damage, coma and death," says state epidemiologist Lon Kightlinger.
"Most of the remainder are suffering from West Nile fever, a less serious form of the disease. Some of the new cases reported Wednesday have not been categorized."
No deaths have been reported in South Dakota so far this year, a drastic change compared to 2003 when 14 people died from the disease.
