A new twist on public health tick surveillance

A University of Massachusetts Amherst infectious disease epidemiologist has received a grant from the National Institutes of Health (NIH) to develop a new surveillance method to better identify specific locations with the highest risk for tick-borne disease transmission.

Existing surveillance programs focus on large geographic areas and involve laborious efforts to trap and count ticks. “Instead of looking for the ticks, we want to focus on the people who have tick-borne disease, then talk to them about their recent activities and capture their use of outdoor spaces using GPS data loggers to help us find out where they may have been exposed,” says Andrew Lover, assistant professor of biostatistics and epidemiology. “We’re trying to develop a whole new way to do tick surveillance that’s focused on people instead of the ticks, is economically efficient and, most importantly, sustainable.”

His study will be funded by a two-year, $427,043 grant from the NIH’s National Institute of Allergy and Infectious Diseases. Lover and his team, including graduate students Teah Snyder and Johanna Ravenhurst, will work with co-investigator Stephen Rich, professor of microbiology and director of TickReport, a UMass Amherst service that allows people to mail in ticks and find out if the ticks carry any disease-causing microbes.

The Centers for Disease Control and Prevention (CDC) estimates that about 300,000 people in the U.S., primarily in the Northeast and Midwest, get Lyme disease each year. Caused by the bacterium Borrelia burgdorferi and transmitted to humans via deer ticks, Lyme disease and other infections transmitted by ticks “are major and emerging public health threats,” Lover says.

The researchers will enroll study participants through UMass Amherst’s University Health Services and Cooley Dickinson Health Care. One group will have a confirmed tick-borne disease, and a second group with no such disease will serve as the control. Both groups will be interviewed and given GPS data loggers to carry for two weeks during their regular outdoor activities.

These data will help the researchers pinpoint specific areas where most of the local tick-borne disease transmission seems to be occurring. “There is this idea that 80% of disease transmission happens in 20% of locations – so a small number of areas can be responsible for the vast majority of infections,” Lover says.

Lover and his team will perform comprehensive tick surveys in areas that their data suggest have very high and very low risk. In his Laboratory of Medical Zoology, home of the TickReport program, Rich and colleagues will test these ticks for a range of pathogens.

“We will compare tick abundance and pathogen prevalence between sites to validate results from the spatial analyses,” Lover explains.

Once identified, the locations with the highest risk can be targeted for intensive interventions, such as clearing overhanging vegetation, landscaping with wood chips or marking the location with specific signage to alert people. Lover says if the study proves successful, the surveillance method will be shared with other communities in Massachusetts and beyond, where tick-borne diseases are prevalent.

“Our findings will dramatically expand our ability to directly and efficiently target the limited resources available for surveillance and interventions to spaces where they will have the highest impact to address an important public health problem,” Lover says.

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