West Nile found in Grand Forks County

The first two human cases of West Nile virus this year in Grand Forks County have been confirmed by the North Dakota Department of Health.

One case has been classified as meningitis, the other as the less-severe “non-neural-invasive,” meaning it is neither meningitis or encephalitis, according to Michelle Feist, epidemiologist with the state health department.

So far this year, North Dakota has 19 confirmed cases of West Nile virus in humans, not counting the pair in Grand Forks County, she said. When new information is released Wednesday, that number is likely to increase.

“There are cases we’re investigating,” she said. August is typically the peak month for West Nile virus reports. “This is the most activity we’ve had for several years.”

While more cases have been found in eastern North Dakota, West Nile has shown up throughout the state.

“We’re adding new counties every week,” Feist said. “The risk is out there for everybody.”

Transmission of the West Nile virus can even occur into September, Feist said. “If we continue to have warm days and warm evenings, those mosquitoes will continue to be active.”

West Nile virus is a mosquito-borne infection that can cause mild, flu-like symptoms or severe encephalitis.

Although the virus can affect people of all ages, those older than 50 and those with weakened immune systems have an increased risk of developing more serious effects.

The state health department does not disclose information on individual victims’ ages and gender, only statewide totals. Nor does it release victims’ hometowns or if individuals have been hospitalized.

“Most likely, those who develop severe symptoms of the disease, such as meningitis or encephalitis, would be hospitalized,” Feist said. A person who develops West Nile fever from contracting the virus could also be hospitalized.

‘Ideal conditions’

While some may scratch their heads over why West Nile cases have surfaced when mosquitoes — and rains that encourage breeding — have been largely absent, at least one local public health official has not been caught off-guard.

“This is peak season for West Nile and, on our end of it, it’s not really surprising,” said Todd Hanson, supervisor of Grand Forks mosquito control program.

“The conditions have been ideal — hot and dry — for the Culex tarsalis, the most common mosquito for transmitting the virus in our region,” he said.

Add to that the unusually mild winter, which probably allowed a larger percentage of the mosquitoes to survive and re-emerge in spring, all this works in favor of the tiny insect that can cause big health consequences.

“Overall the mosquito population has been low” this summer, Hanson said, fueling a false sense of security.

“When we don’t have the nuisance mosquitoes, it kind of runs against us in public health. People don’t put on repellent.”

‘Take precautions’

The state health department urges people to take precautions to prevent being bitten by the mosquito which transmits the virus.

“We recommend wearing the repellent, DEET,” Hanson said. The product is approved by the American Academy of Pediatrics for children as young as two months.

He also emphasized that “the best thing is for people to survey their property for standing water and eliminate it. If you have a rain barrel, you could be raising mosquitoes.”

He recommends wearing long pants and shirts with long sleeves when outside.

Mosquitoes are more active in the evening, he said, but can also be bothersome during the day, when people are outside and working in their gardens.

“Take precautions to avoid being bitten,” he said, “even though it doesn’t look like (mosquitoes are) out there. All it takes is one mosquito to bite you and transmit the West Nile virus.”

Hanson said his department has been “very aggressive” in its mosquito-fighting operations.

“We’re running 21 traps, more than we usually do, and a very comprehensive larvicide program,” he said. “We haven’t had any West Nile positives in our mosquito pools.”

Most people infected with the virus do not develop symptoms, the health department said in a news release. Sometimes, mild illness results one to two weeks after exposure with fever, headache, body aches, skin rash and swollen lymph nodes.

Less than one percent of infected people may develop a serious illness that includes encephalitis, or inflammation of the brain. They may experience headache, high fever, neck stiffness, disorientation, convulsions, and muscle weakness.

Infection may prove fatal, especially among the elderly, in a small number of those who develop encephalitis.

In North Dakota, the West Nile virus has been found in humans every year since 2002, when surveillance by the state health department began.

Throughout the United States, there were 43 West Nile-related deaths in 2011 in 18 states and 57 such deaths in 17 states in 2010.

North Dakota has seen no deaths due to the West Nile virus since 2007.

In Minnesota, there has been one West Nile-related death so far this year and one in 2011.

Pamela Knudson is a reporter at the Grand Forks Herald, which is owned by Forum Communications Co.

Tags: life, news, health