Thanks to the research of a Concordia College professor and six biology students, public health workers and doctors in the Fargo-Moorhead area have another possible, though rare, culprit to investigate when a toddler can’t seem to shake a stubborn cough — the nematode parasite Toxocara.
Dr. John Flaspohler, associate professor and chair of the biology department at Concordia, has been studying parasites for decades.
His prior work has focused on diseases such as African sleeping sickness and leishmaniasis. Both diseases are caused by single-celled parasites and spread by insect vectors, and both can kill, though neither is endemic in humans in the U.S.
“I’m a molecular biologist by training,” said Flaspohler, who teaches cell biology, microbiology, genetics and molecular biology, and immunology and parasitology courses at Concordia.
In order to capture his students’ interest in something a little closer to home, Flaspohler looked into parasites that could potentially be impacting his own community.
The roundworm Toxocara fit the bill. While commonly found in dogs and cats, it can occasionally be passed on to humans, typically via ingestion of eggs in soil contaminated by an infected pet’s feces, Flaspohler said.
According to the Centers for Disease Control, many people who do get infected with toxocariasis don’t have any symptoms at all, but some people develop fevers, coughing, or abdominal pain, all symptoms shared by many more common ailments.
When doctors know the worm is present in an environment, they can add it to the list of potential causes for a patient’s symptoms. If Toxocara is not present in the environment, a toxocariasis diagnosis becomes much less likely.
But are Toxocara roundworms present in the Red River Valley?
While the worms can hatch inside a human, the larvae can’t complete their life cycle there. Instead, they go dormant after migrating throughout the body, provoking an immune response that can result in symptoms.
The project began in January 2020.
Flaspohler and his students — Miriah Forness, Matthew Bye, Natalie DuBois, Luke Evans, Jordan Oliphant, and Sally Nelson — collected eight soil samples each from 12 different parks across Moorhead, all within a mile of residential areas.
From those samples, they isolated genomic DNA, tested it, and verified their results, finding genetic evidence for Toxocara in five of the 12 parks.
Then they presented their research at an online conference and wrote a paper, “Molecular surveillance detects the zoonotic nematode parasite Toxocara in soils from public spaces in a Minnesota community,” published in the peer-reviewed “Bios: A Quarterly Journal of Biology,” Volume 93, Issue 4.
All six biology students gained firsthand research experience through their work, including authorship credit in a scientific, academic publication. One continued in academia, heading to graduate school, and the others continued in related fields, including two in medical school and another in public health.
“They had fun and interacted well,” Flaspohler said. “Whatever they do later, I think (the paper) is going to be impressive for them.”
The paper states in its final paragraphs: “This report emphasizes the continuing need for education of pet owners regarding the potential public health threat these animals and their parasites constitute.” The paper recommends proper disposal of pet waste, fencing to prevent animals from using common areas where children play, and proper hygiene — especially instructing children to wash their hands before eating. Quality veterinary care and regularly scheduled pet deworming are also advised.
“Veterinarians are all over this. They’re very aware of the impact of it,” Flaspohler said.
There are potential consequences for humans, too, even if they don’t have symptoms. Some scientists theorize that Toxocariasis acquired in youth could potentially contribute to reduced cognitive skills later in life, the paper states, so it’s worth researching further.
“It was a great opportunity to pose a basic public health question — 'Is there a potential pathogen in my area, around me?’” Flaspohler said, noting he feels privileged to work at a college where he can read one paper about Toxocara and, five years later, launch a project that offers six students a meaningful experience in producing health-related science. “It was gratifying to me, though also a bit alarming, that we found what we were looking for.”
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(Lead photo by Sophie Shankey on Unsplash; cat photo by Tran Mau Tri Tam on Unsplash)