Fighting Tick and Mosquito-Borne Diseases

Fighting Tick and Mosquito-Borne Diseases

By Caroline Schneider, UW–Madison College of Agricultural and Life Sciences

Home to robust populations of ticks and their hosts (namely, mice and deer), Wisconsin has become a hot spot for tick-borne diseases.

Over the past 25 years, deer ticks have trekked from the northern parts of the state to the south and east. They are now found nearly everywhere, lurking in the backcountry, in the wooded areas of neighborhoods, and even in well-manicured lawns.

Wisconsin residents are also encountering more of another well-known pest – mosquitoes. In summer 2017, UW–Madison Professor Susan Paskewitz and her colleagues in entomology trapped 80,000  mosquitoes in Dane County. That’s eight times more than ever observed previously. The Asian tiger mosquito, a species capable of spreading the Zika virus, was also found in Wisconsin in 2017.

As mosquitoes and ticks travel into new territory, exposure to the diseases they carry increases. The good news is, UW–Madison is leading a strong effort to prevent these diseases from spreading.

The Midwest Center of Excellence for Vector-Borne Disease was established at UW–Madison in 2017 with a $10 million grant from the Centers for Disease Control and Prevention to research illnesses transmitted by ticks and mosquitoes and train new professionals who can stop the diseases from spreading.

Led by Paskewitz and Lyric Bartholomay, professor in the UW School of Veterinary Medicine, the center aims to help Wisconsin be better prepared to respond to ongoing cases and stop epidemics before they start.

The investment will allow researchers and public health officials to keep a close watch on a number of pathogens transmitted by ticks and mosquitoes. Lyme disease is the most prevalent tick-borne disease in Wisconsin.

One main objective is to spur collaboration among various sectors – academia, industry and public health – to improve vector surveillance, outbreak responses and prevention efforts. The center’s many partners, including universities, public health departments, clinics and mosquito control districts, can be found in Illinois, Iowa, Michigan and Minnesota, communicating and consulting regularly.

“We’re hearing about things that are happening in neighboring states, so that puts us on alert,” Bartholomay says. “We can then have conversations about how we might respond much more quickly
than if we had to wait for data to be reported at the end of the mosquito and tick seasons.”

To be certain that the right personnel will be available when the next disease or outbreak arises, the Midwest center trains new experts in public health entomology. In addition, the center is educating new researchers to augment the information and ammunition available for combating vector-borne diseases.

As researchers get an idea of where ticks live and what pathogens they harbor, they can come up with ways to reduce tick exposure and disease prevalence. Postdoc Scott Larson hopes to develop new maps that show how the risks of diseases differ across Wisconsin.

Larson and other researchers in the lab are also looking for ways to help homeowners take tick control into their own hands – and their own backyards. Studies conducted in the UW Arboretum show that tick numbers could be reduced through the use of “tick tubes,” short stretches of pipe stuffed with cotton balls coated with an insecticide called permethrin. The tubes are placed near fallen trees or logs that serve as small animal highways. When animals happen upon the tubes, they nab the cotton balls for their nests, and the permethrin transfers to their coats, where it repels and kills ticks.

Tick tubes and other control strategies will become tools for public engagement as experts work to inform and involve more people in the center’s work. Larson has held training sessions and meetings with public health departments and homeowners’ associations in various parts of the state.

A new app launched in May will amplify the public’s role in gathering data and developing prevention methods. The Tick App asks users questions about their possible exposure to ticks and can educate users about safe practices during tick season and how to identify ticks.