West Nile cases prominent in state

COLUMBUS - An Omaha man warned members of a Columbus service club that Nebraska ranked first in the nation in 2006 for West Nile viruses found in blood donors with 47 positives.

Two human deaths were recorded in the state.

So far this year, the Nebraska Department of Health and Human Services has recorded 10 reports of the West Nile virus in the state. One of those was in Platte County and another in Boone.

The department's final report for 2006 recorded 264 clinical cases of West Nile virus.

“Nebraska ranked No. 1 in the nation in 2006 for the number of blood donors infected with West Nile virus,” said Tom Janovsek of Pest Consulting Services Inc. “Most of those were infected along the Platte River valley.”

Janovsek presented his information to the Columbus Noon Optimist Club Friday, information that shed more light on the West Nile virus.

“Probably about 20 percent of all the residents of Columbus are breeding mosquitoes on their property,” he said. “Mosquitoes will breed wherever there is standing water, and the list of areas where this occurs is almost endless.

The most common breeding areas include trash piles, tire piles, roadside ditches, irrigated fields, cattail ponds, rain gutters clogged with debris, catch basins on your patio plant stands and even snow pools for some species of mosquitoes. Any container holding for four days is a potential breeding ground for the two main species of mosquitoes that carry and transmit the virus.”

He said of the two predominant species of mosquito in Nebraska, one of them is nearly the perfect host for the virus.

“This is the reason that I believe Nebraska will never be without the West Nile virus from here on out,” Janovsek said. “This particular species is nearly the perfect host, and Nebraska is its near perfect habitat.”

Janovsek said transmission of the West Nile virus was only possible through the bite of the female mosquito.

“It's the bite of the female that transmits the virus,” he said. “Only the female mosquito sucks blood because she needs a blood meal in order to produce her eggs. The male mosquito eats nectar, sugar water or other dewy type foods and dies immediately after breeding.

Infection occurs when the female mosquito bites and injects its saliva into the puncture wound. The saliva inhibits the blood from clotting in the host, and the West Nile virus is transmitted through the mosquito's saliva.”

Janovsek said the transmission cycle of the virus is usually from mosquito to bird to mosquito to bird. Crows, bluejays and raptors are the birds most vulnerable to the virus, and 70 percent of these birds that are infected will die.

“Mammals are the dead end of the West Nile virus,” he said. “The virus can't be transmitted from human to human or horse to human.”

Janovsek told the group a large majority of all Nebraskans had already been infected, and in most cases there are no symptoms experienced at all. He said the blood supply is now screened for the virus.

Although West Nile is a concern all summer, the peak season for West Nile is usually late August to early September. The peak time of day is early morning and a few hours before and after dusk.

Janovsek said products containing 30-34 percent DEET are most effective, and he warned against using repellents that contained more than 34 percent DEET.