West Nile's new buzz

Over the last few years, West Nile virus has become -- like its carrier, the mosquito -- a pesky and potentially dangerous part of summer. And it already has made its return to Missouri.

As of Tuesday, mosquitoes in St. Louis County tested positive for the disease, as did seven birds from various parts of the state. Three of the birds were from St. Charles County, one from Jefferson County, one in St. Clair County, one in Benton County and one in Jasper County.

A horse in Washington County also tested positive for West Nile.

"We're still in a holding pattern. We have our eyes and ears open for the first human case," said Brian Quinn, spokesman for Missouri Department of Health and Senior Services.

The first signs of the virus in Missouri appeared late last month.

A crow was found May 24 in Osceola in west-central Missouri. The second bird, a grackle, was discovered May 25 in the St. Louis suburb of O'Fallon. Tests at the University of Missouri-Columbia's Veterinary Diagnostic Laboratory confirmed both were infected, officials with the state Department of Health and Senior Services said.

In the past two years that West Nile has been in Missouri, Quinn said, the human cases appeared in August or September, which is the height of mosquito breeding season. However, Quinn said that past experience does not predict what will happen this summer.

Although it might not yet be the height of mosquito breeding season, there are still plenty of mosquitoes.

To combat the mosquito population already out there, Cape Girardeau and Scott City regularly spray areas of the cities with a mixture of mineral oil and the insecticide malathion. Marble Hill, Chaffee and Perryville also spray their towns with an insecticide mixture to kill mosquitoes.

Jackson is one of the few cities in the area that does not have a spraying program.

The Cape Girardeau Parks and Recreation Department is in charge of mosquito spraying in the city's recreation areas while the city's Public Works Department handles the remainder.

Public works employee Randy McLain sprays the city twice a week, covering between 30 and 45 miles on each trip. McLain said the spraying is stepped up to three times a week later in the summer.

Cape Girardeau also deposits larvacides into standing water to kill mosquito larvae.

This work is repeated regularly throughout the summer.

"I don't think most people know that mosquitoes breed and reproduce every two weeks," McLain said.

No mosquitoes in Southeast Missouri have been found to have West Nile, said Dr. Christina Frazier, a Southeast Missouri State University biology professor who works with the Missouri Department of Health and Senior Services to test mosquitoes from all over the state for West Nile virus, St. Louis encephalitis and LaCrosse encephalitis.

Frazier said that the presence of mosquitoes with the disease in St. Louis County shows the virus is active; however, it does not guarantee that humans cases will follow.

In the two years West Nile has been present in Missouri, infected mosquitoes and birds have not shown up until later in the summer, but Frazier said that the disease's early arrival this year is no reason to panic.

Karen Yates, coordinator for the state health department's West Nile virus program, agreed.

"It's not something people should be afraid of," she said. While other states are telling people to stay indoors at dusk, prime-time for mosquitoes, Yates said Missouri's health department believes that people should be able to go outdoors anytime, as long as people take the appropriate precautions.

"We want to reach an appropriate level of concern," Quinn said. "We don't want people to be lackadaisical about it, and we don't want people to be hysterical about it."

Although West Nile had been present in other parts of the world, the disease's first known appearance in the United States was in New York in 1999. The disease then made its way westward and was first identified in Missouri in 2001.

In 2002, 168 human cases of the virus were recorded in Missouri and seven deaths resulted from the virus. There was one confirmed human case in Cape Girardeau County that year.

In addition to the human cases, 662 horses were confirmed as having West Nile in Missouri.

The number of West Nile cases in Missouri dropped in 2003, with 64 human cases detected and eight deaths, as well as 272 equine cases.

While about 80 percent of people infected with West Nile do not show any symptoms, some will become ill with a fever, aches, headache and swollen lymph nodes. In a small number of cases, West Nile will bring about encephalitis, which involves swelling of the brain, or meningitis, involving inflammation of the tissue surrounding the brain and spinal cord. In severe cases, West Nile can cause coma or even death.

Those most at risk are the elderly and people with weakened immune systems.

The Associated Press contributed to this report.

kalfisi@semissourian.com

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