Posted: 8/23/05
Mosquito control can help prevent ësinisterí illness
By David Heiller
Argus News Editor
Dave Geske was not happy.
He had taken me on a drive through Caledonia to show me some mosquito traps that his La Crosse County Health Department, where he works as vector control manager, had set out.
He also pointed out some places where mosquitoes might breed, things like old buckets and especially old tires.
Then Geske found a mosquito paradise in someoneís back yard full of junk.
Thatís when a scowl passed over a face that seems to be good-natured 99 percent of the time. He had walked to a fence line and spied a broken plastic milk jug.
Its bottom was filled with water and leaves and something that I could not see: mosquito larvae. Mosquitoes flew up around us.
He picked one off my shirt and identified it as Aedes triseriatus. Not good, he said. These are the type of mosquitoes that can carry La Crosse viral encephalitis, a severe disease of the central nervous system.
It was a perfect spot for the mosquito to breed. They often are found in holes in trees, because they like things with organic matter that hold water over a prolonged period, or like that plastic jug with leaves in the bottom. ìThatís the kind of organic matter these mosquitoes like,î he said.
Dave set the jug upside down and stomped on it, and that was the end of that little batch of larvae.
A bucket lid lay nearby, also filled with water. Geske turned it over. ìItís because of things like this,î he said, talking about how La Crosse encephalitis is spread.
Geske said his health department crew had been checking and treating this site and three others. He said he would be paying more attention to this one now.
We walked through the yard in search of some mosquito traps that Geske knew were on the site. After a few minutes of poking in the weeds, he found one attached to the bottom of a pole. It looked like a glasses case, black with a lining of brown paper inside.
The trap is filled with a substance that attracts female mosquitoes. They lay their eggs on the paper, which is then sent to a laboratory which analyzes the larvae and tells the La Crosse encephalitis viral count. If the virus is found, Geskeís office will do more active work on that site.
The traps are checked every 8-10 days. They not only give good data, they also reduce the numbers of mosquitoes by attracting the females to that spot, where the eggs can be gathered.
Passionate about skeeters
Dave Geskeís office has a contract to work on mosquito control in Houston County. Itís a big county, and with a staff of only four people, Geske said he needs people help. He welcomes phone calls at 608-785-9771.
Geske and his crew seek out and treat mosquito sites with a bacteria that is harmless to everything except mosquitoes. It kills the insects because they canít digest it. He often treats water that he finds in old tires. That buys people some time so they can eliminate the problem spots. He will talk to the people who own those mosquito condominiums too and encourage them to take care of the problem, like cover the containers or tires, or get rid of them. People are usually responsive, especially when he can show them the mosquito eggs.
ìIn Houston County, Rick Frank has done a nice job with that,î Geske said. Frank coordinates recycling programs in the county.
Geske has been trapping, studying, and killing Aedes triseriatus mosquitoes for most of his 26 years with the La Crosse County Health Department. He speaks about them with a lot of conviction, and with enough detail to make a reporterís head spin. Did you know that females mosquitoes can sense people from 70 feet away? Dave Geske knows that.
He has seen the number of cases of La Crosse viral encephalitis drop from an average of 27 a year over a 10-year period to 5-1/2 cases a year over a 25-year period.
That is very gratifying for Geske. He feels preventing one case pays for his program, given the huge cost of treating someone with the disease. He said the average cost of treating a case of La Crosse encephalitis is $100,000
ìThis is public health, this is prevention,î he said.
A sinister disease
About half of the people who get the disease will have on-going medical issues, and 15 percent of them will have lifelong problems, Geske said. He has interviewed over 200 families inflicted with the disease in his career, and people often tell him that their child is not the same afterwards.
ìItís kind of a sinister disease,î Geske said. ìIt impacts a personís essence.î
In Caledonia, Geske has set out traps on the north and south end of th city because there are more trees there. By monitoring the larva in traps, he can track the progress that the insects are making into the city and places like we explored.
Another type of mosquito, called culex, spreads West Nile virus, which is much less common than La Crosse viral encephalitis. People over age 50 have a higher risk of becoming seriously ill when they get this infection. Symptoms include headache, high fever, stiff neck, mental confusion, muscle weakness, shaking, convulsions, coma, and paralysis.
Fewer than one percent of people who get West Nile Virus become seriously ill. ìWe probably donít even know about most West Nile Virus cases,î Geske said.
The City of Caledonia paid $1,280 for the mosquito program last year. This year will be about the same, according to city clerk Bob Nelson. Those fees had been paid for by the county up until 2004, but funding was cut due to budget cuts from the state. Geske made a pitch to the city to keep the program going, and the city council agreed. Houston County has $2,050 budgeted for mosquito control in 2005.
Nelson said on August 17 that enforcement is the most difficult part about any city law.
Cooperation is needed and appreciated, Nelson said, but people donít always remove troublesome items like tires when asked by Geske and city officials. The city then has to send out letters. Nelson had 10 of them on his desk when I called him.
Nelson thinks Geskeís program is well worth it because of the ill effects of both La Crosse encephalitis and West Nile virus.
ìChildren especially and seniors bitten by the La Crosse encephalitis mosquito have the possibility of near permanent brain damage or even death,î he said. ìSo itís kind of a necessary thing to do.î
Symptoms, prevention
La Crosse viral encephalitis can affect anyone, but most often it shows up in children. It is a very common disease in the U.S. There are an average of six cases a year in the La Crosse area. The disease peaks in August and September.
It is carried by Aedes triseriatus, one of 26 types of mosquitoes found in Houston County.
Symptoms include fever, severe headache, vomiting, drowsiness, or convulsions. Children should use mosquito repellent and wear light-colored clothing that covers their arms and legs, especially in the late afternoon, which is the peak biting period.
People should also try to mosquito-proof their homes by having good screens and not leaving doors open.
Few people die from the disease, but hospital care for 7-10 days is usually required. There is no specific drug known to alter the course of the disease.
Caledonia Argus
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507/724-3475
E-Mail: editor.argus@ecm-inc.com