http://www.leadertelegram.com/news/front_page/article_094b09ec-2500-11e4-a854-0019bb2963f4.html
Disease-borne tick population studied in Eau Claire County; preliminary results troubling
Preliminary results of a study started in May show that about one-fourth of deer ticks collected at Lowes Creek and Big Falls county parks contain the bacteria that causes Lyme disease.
“It’s incredibly high,” said Brady Olson, a microbiologist with the Eau Claire City-County Health Department, as he observed results from ticks he had just run through a real-time polymerase chain reaction, or PCR, a laboratory technique used to magnify and detect tiny bits of bacterial DNA extracted from ticks and identify it as the culprit that causes Lyme disease.
Department staff chose the two Eau Claire County parks to collect ticks used in the study because of their popularity with outdoors enthusiasts, said Shane Sanderson, the Health Department’s environmental health director.
“I’m a little more concerned about places people use,” he said.
The three-year study is being paid for by a grant from the federal Centers for Disease Control and Prevention The study is occurring here because the Eau Claire area is a hot spot for tick-borne illnesses.
As part of the study, the CDC is attempting to determine whether Lyme disease is worsening in the Midwest because of a warming climate. Scientists hope to learn about seasonal variations in ticks and the percentage that carry the Lyme bacteria.
In addition to the study, the grant also paid for the real-time PCR process, which can be put to other uses, Sanderson said. For instance, department staff hopes to use it next summer to check for E. coli levels at beaches when they are closed because of high bacterial levels, he said.
Trolling for ticks
Since May, Health Department staff members and student volunteers have been conducting “tick drags” once per week at the two county parks, alternating parks each week. The process involves dragging a weighted 4-foot-by-4-foot piece of cloth through tall grass. Ticks that cling to the cloth are collected and plopped into containers of alcohol.
At the lab, Olson sorts ticks, placing them into separate categories to find the smaller “deer” or “black-legged” ticks that carry Lyme and other diseases. He runs them through the PCR process to determine whether the ticks contain the bacteria to transmit illnesses.
After finding plenty of ticks in May and June, the tick-dragging crew came up empty in July. That finding backs up the thought that ticks tend to be scarce in summer and more abundant in spring and fall.
“The study is still preliminary, but if patterns show ticks are uncommon in July, that might have health implications,” Sanderson said. “If you are planning a picnic, you might think of July.”