Ticks—they’re gross, they’re a public health menace, and in NYU’s Department of Biology, they’re also a valuable teaching tool.

On a warm Friday morning in late October, about a dozen NYU students boarded a bus from the Silver Center to the Cary Institute, an ecology center in the Hudson Valley, for an unusual class assignment. Upon their arrival, they donned white coveralls, taped the pockets closed, and tucked the pant legs into tall white socks.

students putting on white coveralls

Professor Kirov addresses students putting on white coveralls

sign alerting hikers to dangers of ticks

Then they headed into the woods to collect ticks. Because these parasites are notoriously hard to spot—ranging in size from poppy seeds (nymphs) to apple seeds (adult)—the students used a tried and true method perfected by field researchers: dragging large rectangles of white fabric on the forest floor to see what would stick. 

students in white coveralls filing into the woods

student dragging white fabric along the ground

sun shines through the trees as students hold up white fabric in the woods

student points to a spot on white fabric that another student is holding up

group of students smiling as they examine white fabric

Students plucked the tiny arachnids from the fabric with forceps and deposited them into vials that they labeled as male, female, or nymph. In roughly an hour, the class collected more than 100 ticks.

closeup of a student's hand using tweezers to pluck a tick from fabric

other students and Professor Killelea look on as one student uses tweezers to put a tick in a vial

closeup of student with a blue marker in their hand plucking tick off of a fabric that other students are holding steady

The field trip was the centerpiece of the syllabus for At the Bench: Disease Ecology, a course that combines the fields of environmental studies with molecular biology. Students enrolled in it take part in a semester-long research project on Lyme and other illnesses transmitted by ticks. Lyme is the most prevalent vector-borne disease in the U.S. and is particularly common in New York State, where it infects more than 7,000 people each year. 

students examining white fabric in dark woods

students in a clearing with white fabric and a vial

This is the 10th year that Nikolai Kirov, clinical professor of biology, is teaching the class, which he developed with Mary Killilea, clinical professor of environmental studies and now the associate dean of academic affairs and innovation in the School of Professional Studies. Together they created the upper-level undergraduate course as a way to explore the environmental determinants of disease and combine theoretical ideas with experiential field- and lab-based learning on a critical public health issue facing New Yorkers.

Professor Killelea lecturing to students in white coveralls

“Students like this mix—the opportunity to explore two very different fields, which are both on the cutting edge,” said Kirov. 

After Killelea led students through the woods to collect ticks, Kirov stowed the vials in a cooler of dry ice to bus them back to the Silver Center. In a series of lab activities over the following weeks, students learned to isolate tick DNA and use polymerase chain reaction (PCR) methods to test for the presence of Borrelia burgdorferi, the bacteria that causes Lyme disease, as well as Babesia and Anaplasma, other pathogens carried by ticks.

Professor Kirov writing on a white board in class

students pipetting

students holding assay trays in a lab

“The course is designed to be open-ended. The students don’t know what the results will be, unlike other experimental courses where the results are more or less known,” said Kirov. 

Students finished the semester by delving into epidemiological modeling to analyze the prevalence of disease carried by the ticks they collected and compared their results with infection rates over time.

Professor Kirov looks on as student in gloves operates lab machinery

This year, fully half of the ticks collected on the grounds of the Cary Institute tested positive for the Lyme disease-causing bacteria, a rate of Borrelia burgdorferi that was relatively stable compared to past years.

“The course was driven by my own curiosity, both about Lyme and whether I would be able to meet the challenge of creating a new experimental course,” Kirov added. “Lyme is a real health issue, and I thought it would be important for students—many of whom are pre-med—to investigate such an important subject.”