UND parasite researchers do big work in disease, ecology studies
UND professor Vasyl Tkach can appreciate a good tapeworm.
"They want you to have happy lives," said Tkach, using a set of forceps to prod at a mass of preserved white worms in a petri dish. His colleague, UND professor Jefferson Vaughan, can summarize the motivation of the common parasite in brief.
"They don't want to kill you," said Vaughan. "They just want your nutrients."
So it goes among the parasitologists—those who study parasites—in the UND Department of Biology. Broadly speaking, the Centers for Disease Control describes a parasite as an organism that "lives on or in a host and gets its food from or at the expense of its host."
The definition applies to a huge range of critters, reaching from all-too-familiar head lice right down to single-celled protozoans. The two researchers make it their business to be familiar with the whole squirmy family, including those more malevolent than the comparatively friendly tapeworm.
They discussed their work Thursday in a first floor classroom of Starcher Hall on the UND campus, but Tkach says the discipline can take scientists far beyond the limits of the frozen plains of North Dakota.
He has a research trip to the South American country of Chile planned over the university's spring break and, after that, he's headed to the Brazilian Amazon on a river expedition to study exotic parasite species in their natural rainforest habitat.
"It's basically like when you watch 'Indiana Jones,' " Tkach said. "But when he just did it for the camera, we endure it for real—the heat, the skeeters, the jungle, all that stuff."
Indiana Jones was more fixated by snakes than tapeworms, but he might have appreciated the scope of the work being done by parasitologists such as Tkach and Vaughan.
In separate upcoming studies, both men are focusing their efforts on a parasite of small size and massive impact—a set of microscopic organisms which cause malaria.
There are several forms of malaria that aren't dangerous to humans, but just a few do more than enough harm. The organisms that infect us make their living on certain species of mosquitos and spread when the insects feed on blood.
The World Health Organization estimated in 2015 that nearly half the global population was at risk of contracting malaria. In that same year, researchers at WHO believe there were as many as 212 million cases of malaria worldwide, resulting in 429,000 deaths.
Tkach is going to Brazil primarily to study strains of malaria and other diseases found in rainforest birds, a group of animals which increasingly come into contact with expanding human settlements. Vaughan just received word that the National Institutes of Health approved nearly $140,000 in funding for his study aimed at putting a nail through the heart of mosquito-borne malaria in the Central American nation of Belize.
"Malaria has been the scourge of humanity for many, many years," he said. "We tried to eradicate it back in the 1950s and '60s, but it got out from under us."
In recent years, there's been a resurgence in the fight against malaria. Vaughan believes Central America could be a place where the disease is someday eradicated by humans, and he thinks cows might help us do it. Drugs used by farmers to kill more benign parasites that live among cattle stock also work on the mosquitos that carry malaria.
Vaughan's study probes at what he calls a simple concept—using the drug to kill mosquitos could in turn reduce the spread of malaria parasites to humans. Vaughan said he's still arranging the logistics of his research, the planning of which could take up the next year.
The kind of work Vaughan is preparing for is a strong example of the applied side of parasitology. In many ways, the researchers share common ground with epidemiologists, or those who study the incidence, geography and potential for controlling disease.
Lyme disease, Zika virus and West Nile virus are all parasite-borne illnesses with ranges of incidence that have grown at an explosive pace. Parasitologists at UND have spent time researching the organisms that carry these diseases and tracking their spread as their territory expands.
Tkach credits the graduate students who devote their studies to parasites for their own unique work in the field, much of which has generated critical interest. Last year, UND Ph.D. graduate Stephen Greiman won a top honor for an early career researcher from the American Society of Parasitologists.
His work, conducted alongside Tkach, pointed to another hard application of parasite science. By studying the intricate relationships between shrews and their parasites in the Arctic—both of which are gaining new habitat from the formerly hard-frozen northern rim—the researchers suggested a warming climate could be driving real change in local ecosystems.
The finding is one example of the capacity for parasite studies to provide a new level of insight into a formerly hidden world, Vaughan said.
"It's these invisible interactions going on that you would never know," he said. "You would never know until you open an animal up—it's never-ending."