By Matt Leingang
The Cincinnati Enquirer

Bob McCandless, with the Northern Kentucky Independent District Health Department, Wednesday removes the netting containing trapped mosquitoes from a trap set in Burlington, one of several in Boone County he'll check. The Cincinnati Enquirer/GLENN HARTONG

David Zanitsch doubts he will fully recover from his 2002 West Nile virus infection, an incident that almost killed him.

The Bridgetown resident, who was bitten by a virus-carrying mosquito while sitting on his back deck, spent a month in a hospital, his brain swollen and the left side of his body temporarily paralyzed.

Since then, Zanitsch, now 63, has learned to walk again, but his coordination is sometimes poor, and he easily loses balance. But that hasn't stopped him from trying to educate the public about wearing mosquito repellent and checking their back yards for stagnant water.

"I'm very lucky," said Zanitsch, who makes speaking appearances.

Although still a rare infectious disease, the West Nile virus has increased awareness and changed the way many Greater Cincinnatians enjoy summer, and the way public health agencies go about business.

The 2002 outbreak cost the country at least $139 million in medical services and lost productivity, according to the U.S. Centers for Disease Control and Prevention.

Last year, the mosquito-borne illness affected 9,862 people nationwide - less than 0.003 percent of the U.S. population.

ONLINE POLL

ABOUT THE VIRUS

West Nile virus is commonly found in Africa, West Asia and the Middle East. It is closely related to the St. Louis encephalitis virus found in the United States. West Nile can infect humans, birds, mosquitoes, horses and some other mammals. Until 1999, West Nile virus had not previously been documented in the Western Hemisphere. It is not known from where the U.S. virus originated, but it is most closely related genetically to strains found in the Middle East. West Nile fever is a mild disease in people, characterized by flu-like symptoms. It typically lasts only a few days and does not appear to cause any long-term health effects. More severe forms are West Nile encephalitis, West Nile meningitis and West Nile meningoencephalitis. Encephalitis is an inflammation of the brain, meningitis is an inflammation of the membrane around the brain and the spinal cord, and meningoencephalitis refers to inflammation of the brain and the membrane. Source: U.S. Centers for Disease Control and Prevention

WEST NILE CASES

Fourteen human cases of West Nile virus have surfaced so far this year in the United States. The cases are in New Mexico, Arizona, California, South Dakota and Wyoming. By the end of last year, only five states - Alaska, Hawaii, Maine, Oregon and Washington - had no human cases of West Nile virus. The top 10: State cases deaths 1. Colorado 2,947 63 2. Nebraska 1,942 29 3. South Dakota 1,039 14 4. Texas 720 37 5. North Dakota 617 5 6. Wyoming 375 9 7. Pennsylvania 237 8 8. Montana 222 4 9. New Mexico 209 4 10. Minnesota 148 4 U.S. total 9,862 264 Source: Centers for Disease Control and Prevention

But it was the largest count so far, and 264 people died, including eight in Ohio, four in Indiana and one in Kentucky.

West Nile cases typically develop in August and September. But New Mexico, Arizona, California, South Dakota and Wyoming already have human cases this year.

Last Friday, it was announced that mosquitoes found in Sycamore Township were the first in Ohio to test positive for the virus.

Getting prepared

Most health officials say it's impossible to predict the number of human cases this year, but precautions are already being taken:

• The Hoxworth Blood Center, which collects and distributes blood for all hospitals in Greater Cincinnati, won't collect blood from prospective donors who have recently had headaches or a fever - possible signs of a West Nile infection. The loss of those potential donors can cause a slight dip in the area's overall blood supply from time to time, said Dr. Patricia Carey, the center's medical director.

Last year, Hoxworth began testing every unit of collected blood for West Nile, a move credited with catching three infected donors. All of their blood was destroyed to prevent transfusion to a patient. But nationwide, the threat has not been eliminated, according to the CDC. Two patients got the virus from a blood transfusion in 2003 - one in Texas and the other in Nebraska. Both patients recovered.

• West Nile is now a frequent topic of conversation between family physicians and their patients - at least it should be, Dr. Aletha Tippett said. The Blue Ash doctor is president of the Southwestern Ohio Society of Family Physicians.

"Right around this time of year, we start to get calls from patients every day asking about the West Nile virus," Tippett said. "We stress prevention - wear the right clothing, don't go to areas that are known to have heavy swarms of mosquitoes.

Because symptoms of the flu are very similar to West Nile fever, differentiating between the two can be tricky.

"Taking a good patient history becomes even more important," Tippett said. "So we ask questions similar to the way we diagnose for poison ivy. Where have you been? What have you been doing?"

• Disease surveillance. Once again this year, local health departments will trap mosquitoes as the main way of tracking the disease. The state health departments in both Ohio and Kentucky do the actual testing.

• Controlling the mosquito population. Almost two dozen county, village and township workers have been certified to place larvae-killing "dunks" when they find stagnant water in sewers, parks and other public properties. Last year's "hot spots" - areas that had the highest concentrations of infected mosquitoes - included parts of Anderson Township, Green Township, Newtown and Boone County. But officials caution that that is not necessarily an indication of what to expect this year.

"This has certainly added to our workload," said Steve Divine, director of environmental services at the Northern Kentucky Health District. "We get a lot of phone calls this time of year, and it takes a lot of time to set traps, go back the next day to collect the mosquitoes and then ship them out to be tested."

Who's at risk?

Most people who are bitten by an infected mosquito will not get sick, according to the CDC. Typical symptoms include a slight fever, body aches, neck stiffness, vomiting and confusion.

Less than 1 percent of those infected will become seriously ill. Elderly people and those who have weakened immune systems are at greatest risk. In the most serious cases, it can induce a deadly inflammation of the brain.

Although treatments and vaccines against the virus are being worked on, they are still years away from public use, according to the CDC.

"There is no elimination" of West Nile virus, said Dan Collins, director of environmental health for Warren County. "There's no way to eliminate every infected mosquito. It's here to stay."

However, once you get it, you are likely immune. But how long that immunity lasts is unknown.

"I'm supposedly immune," said Zanitsch, who still routinely wears socks, shoes, long pants and a long-sleeved shirt when he's outdoors in the evenings and early mornings, when mosquitoes are likely to be out.

"But they (doctors) don't know enough about this disease, so it's not worth taking any chances," Zanitsch said.

E-mail mleingang@enquirer.com