Study of Wisconsin Ticks

Study of Wisconsin ticks shows more than half in northwest carry disease

Duluth News Tribune by Shelley Nelson, Forum News Service on Jul 21, 2015 at 4:38 p.m.

SUPERIOR, Wis. A specialized medical diagnostic reference laboratory has spent the last several years collecting more than 2,000 ticks and studying tick-borne illnesses with some surprising results.

Coppe Laboratories of Waukesha, just west of Milwaukee, had contributions from the Wisconsin Department of Natural Resource and private citizens to collect the ticks.

The goal of the research was focused on determining what percentage of ticks carry the bacteria that causes Lyme disease and what other organisms might be present. The testing revealed that not only the borrelia bacteria (Lyme disease) was present in many of the ticks, but the powassan/deer tick virus infected some as well.

Of special note, in certain “hyper-endemic” regions of northwest Wisconsin, more than half the ticks were infected with the Lyme disease bacteria and powassan was present in a large number.

Wisconsin has the highest incidence of tick-borne diseases in the Midwest, but the northeast region of the United States ranks highest overall.

“Results of this study show that the ticks across Wisconsin have the potential for transmitting multiple infectious agents in a single bite,” said Dr. Konstance Knox, chief executive officer of Coppe Labs.

“The powassan virus is an emerging tick-borne illness in the United States, but its cousin the tick-borne encephalitis virus, has long been recognized to cause significant illness in Europe.”

Powassan virus can infect within 15 minutes of the tick bite.

The Wisconsin Department of Health Services reports more than 1,700 cases of confirmed Lyme disease in 2013 and estimates the actual number of cases is closer to 4,000. It is the highest reported tick-borne disease in Wisconsin, with more than 23,000 cases reported between 1980 and 2010. The highest number of cases occur in the north and northwestern region.

According to the Coppe Labs’ study, the ticks carrying diseases are in almost every county in Wisconsin.

In the study, the lab also found there were a minor number of ticks with the protozoan infection babesia. Babesiosis is caused by microscopic parasites that infect red blood cells and is transmitted by the same tick that causes Lyme disease, said Dr. David Baewer, chief medical officer at Coppe Laboratories. He said the infection can range in severity from asymptomatic to life threatening.

The infection is both treatable and preventable. Many people who are infected with babesia feel fine and do not have any symptoms. Some people develop nonspecific symptoms, such as fever, chills, sweats, headache, body aches, loss of appetite, nausea or fatigue. Severe infections can cause destruction of large numbers of blood cells, which causes jaundice (yellowing of the skin) and dark urine, Baewer said.

Babesiosis is the single most common transfusion-related infection and a recent FDA panel suggested that the blood banks begin screening for babesia in all blood donors, Coppe Laboratories’ has tested for babesia in Wisconsin ticks, and this research is being translated into the development of a means to detect this parasite, Baewer said.