North Dakota may be one of the states where West Nile virus can cause a high rate of neuroinvasive disease, a new study in the March-April 2010 issue of Public Health Reports suggests.

The study led by Borchardt S.M. and colleagues at the Fargo Veterans Administration Medical Center shows that the annual cumulative incidence of West Nile neuroinvasive disease can be as high as 14.6 per 100,000 population.

West Nile virus or WNV can cause seasonal epidemics of neuroinvasive disease and febrile illness, which hit the central plains states particularly hard, according to the background information in the study report.

The researchers studied the cases of West Nile virus disease reported in North Dakota, a highly epidemic state, for a period of six years between Aug 2002 and Dec 2007.

Identified are a total of 1246 cases of West Nile virus disease in North Dakota of which 183 cases experienced neuroinvasive disease such as meningitis, encephalitis or acute flaccid paralysis.

The annual cumulative incidence of neuroinvasive disease ranged from 0.3 per 100,000 to 14.6 per 100,000 population, the study found.

The authors concluded that North Dakota offers favorable conditions for West Nile virus illness and improved targeted prevention measures are needed to reduce the risk from the virus.

To prevent spreading of West Nile virus, health officials often recommends use of insect repellents to fight mosquitoes that can host viruses and viral diseases.

By Jimmy Downs