By Rebecca Jasulevicz
On April 3, Catherine Flanley, an ESU alumna, was awarded the 2014 Thesis of the Year during the Student Research, Scholarly & Entrepreneurial Activity Symposium for her work with New Jersey black bears.
“When this whole thing started and Dr. Aldras and Dr. Huffman said, ‘I think you should do a thesis,’ did I ever think that I would be working with black bears? Not in a hundred years,” said Flanley.
Specifically, Flanley looked at the serologic prevalence of Toxoplasma gondii, Trichinella spiralis, and Borrelia burgdorferi, three parasites that have plagued the bear population for years.
The infludence of these parasites goes beyond the bear population, especially during seasons when humans tend to consume wild game.
Throughout 2012, Flanley worked to take tissue and blood samples, extracted teeth, tagged and tattooed the bears, and removed ticks from their fur and skin.
The main goals of Flanley’s study were to determine each pathogen’s prevalence, analyze past data with current data, determine the risk to humans, and provide a reference point for future population management.
“Black bears are opportunistic feeders. They eat most herbaceous material, plant material, but they will eat insects, vertebrates, and also dead things. They also eat garbage, so…they are prone to parasitic infections,” Flanley said.
She continued, “In healthy individuals, Toxoplasma gondii is not an issue because your immune system walls it off and you don’t really have to worry about it. It’s if you’re immuno-compromised or pregnant that you have an issue.”
These issues can be avoided by taking special precautions during hunting season.
Sportsmen should wear gloves when skinning and dissecting bears, and meat should be cooked properly.
In addition, washing your hands after gardening can prevent the spread of diseases that may be present in the soil.
Toxoplasma gondii is known to start in cats, and oocysts — sacs containing genetic material — are shed in the cats’ fecal matter, which allows them to enter the environment.
Flanley said, “Those oocysts can be ingested by small mammals or birds, and they can contaminate food and water supplies as well.”
Humans can then ingest those oocycts by eating contaminated meat or drinking infested water.
Toxoplasma gondii was more prevalent in male bears than females. This surprised Flanley, as most dumpster divers are females.
However, the males have a wider home range, and so have more of a chance to be exposed to the oocycsts in the environment.
Flanley also looked at whether the age of the bear had any effect on the prevalence of toxins and parasitic infections, and found that yearlings, bears between one and two years of age, have the highest prevalence.
This is because at this age the bears are expected to find food for themselves, and so these individuals dumpster dive much more frequently than adults and cubs.
Prevalence of Toxoplasma gondii was 73.7 percent, which, according to Flanley, “was on target with the literature I read.”
As for Trichinella spiralis, outbreaks typically only occur by eating undercooked meat, especially when it comes to wild game.
In this easily preventable disease, nemotodes will reproduce while in the animal’s intestines and then enter the rest of the body’s tissues.
This creates cycts throughout the body that will eventually be calcified over.
Trichinella spiralis’s prevalence was 0 percent, which contradicted the literature values that had previously been determined to be about 1 percent to 2 percent.
This may have been a result of insensitive test equipment.
Borrelia burgdorferi, the last parasite that Flanley tested for, is one of the main causes of Lyme Disease.
Pests like ticks easily carry this parasite.
Flanley said, “Why should we be concerned? Because most of the cases of Lyme Disease that occur are in the northeast.”
In this disease, deer ticks will find a host to engorge themselves on, and then they will molt, spreading the disease further throughout the environment.
In 2012, ESU students worked to develop a product called Lyme-Aid.
This easy-to-use home testing kit allows people to safely remove ticks from pets or their own bodies.
Lyme-Aid owners can then send the ticks to ESU to be tested for Lyme Disease.
The prevalence of Borrelia burgdorferi was 87 percent, meeting Flanley’s expectations.
Ticks were equally prevalent in bears of all ages, as well as for males and females.
Flanley ended her presentation by thanking everyone who made her attainment of the Thesis of the Year award possible, including Dr. Aldras, Dr. Huffman, Dr. Milewski, ESU’s graduate school program, her family and friends, the New Jersey Division of Fish & Wildlife, and also her fellow graduate students.
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