Serendipity and Science: The Journey of Dr. John Hawdon
- Lori Preci
- Mar 3
- 5 min read
Dr. John Hawdon didn’t set out to study parasites, but life has a funny way of leading the curious down paths they never expected. A stack of rejection letters, an unplanned teaching job, a retired greyhound with a stubborn infection, and the wisdom of a Haitian voodoo priest—none of it was part of the plan.
Dr. Hawdon’s Winding Path to Parasitology
As a young boy with a love for animals and biology, veterinary science seemed like the natural choice for Dr. John Hawdon. However, as he advanced in his collegiate studies, he found himself captivated by something else entirely. In the 1970s, molecular biology captured his attention through its cutting-edge transformation of the field of biological research with breakthroughs in gene cloning and recombinant DNA. However, as a senior, Dr. Hawdon had already declared an animal science degree.
With little time to spare, he decided to get creative and reached out to a research lab, only to learn that a prerequisite course stood in his way. Not one to shy away from a challenge, Dr. Hawdon completed the requirement and secured a position in the lab, hoping to gain hands-on experience to strengthen his graduate school applications for molecular biology. But life, like science, doesn’t always go as planned, and his applications were met with rejection.
Forced to pivot, Dr. Hawdon took a teaching job at a proprietary technical school—not an obvious stepping stone into research, but it paid the bills. His schedule was relentless, teaching five courses a day, five days a week, but in the midst of that relentless schedule, fate quietly intervened. One of the courses he taught was parasitology, and those parasites were … interesting. For Dr. Hawdon, these organisms pointed to a field rich with questions waiting to be answered.
In the meantime, after two years of persistent effort in pursuit of research, Dr. Hawdon landed a position at the University of Pittsburgh, where he worked with C. elegans, a microscopic nematode, or roundworm making waves in biological research. Through this research, Dr. Hawdon realized his true interests lay in worms with direct consequences for human health, and just like that, his passion for parasitology clicked into focus.
With a renewed sense of determination, Dr. Hawdon pursued graduate studies in parasitology at the University of Pennsylvania, where he met Peter Hotez, a rising figure in vaccine development for parasitic diseases. Their collaboration led Dr. Hawdon to a postdoctoral position at Yale University’s MacArthur Center for Molecular Parasitology, and soon after, he became an Associate Research Scientist in the Medical Helminthology Laboratory in the Department of Epidemiology and Public Health at Yale. Nine years later, he joined George Washington University, where he would carve out his own niche in the field.
With the support of his first independent grant, he pivoted from vaccine research and leaned into the molecular mechanisms of parasitic worms and their impact on human health. Over time, his work has helped shape the field of parasitology, inspiring a new generation of scientists. Reflecting on this, Dr. Hawdon calls it “a piece of big luck,” but more than luck, it was his persistence, adaptability, and readiness to follow wherever science led him.
When asked what piece of advice has guided his career, Dr. Hawdon shared his personal take on Louis Pasteur’s famous words:
"Serendipity favors the prepared mind."
Looking at his journey, it’s hard to disagree.
Tackling a Growing Threat: Anthelmintic Resistance
Today, Dr. Hawdon’s research focuses on tackling one of parasitology’s most pressing challenges: anthelmintic resistance. Anthelmintics, or anti-parasitic drugs, have historically been highly effective in treating helminthiasis—infections caused by helminths or parasitic worms—eliminating about 99% of susceptible helminths. However, misuse of anthelmintic drugs in agriculture and human medicine has fueled the emergence of drug-resistant strains, posing a serious threat to both human and animal health.
The consequences are especially dire within the livestock industry. Sheep farmers, for example, have long heavily relied on deworming treatments to prevent helminthiasis in their livestock. However, in some regions, the misuse of anthelmintics has spurred the evolution of resistant nematodes, devastating sheep farms worldwide. This raises concerns that, without alternative strategies to control resistance, conventional livestock farming could become unsustainable.
Dr. Hawdon’s lab is at the forefront of understanding the genetic mechanics driving resistance. In a 2024 publication, his team characterized a naturally occurring strain of Ancylostoma caninum, a canine hookworm, resistant to three major classes of anthelmintics and identified genetic mutations associated with the resistance. The lab also observed altered larval activation responses in the resistant strains, suggesting changes in the signaling pathways involved in the activation process. These findings may inform future strategies for managing drug-resistant hookworm populations.
Dr. Hawdon also notes the potential emergence of resistance in human medicine. While current treatments for helminthiasis are largely effective, early warning signs suggest that resistance may already be developing as some deworming programs have reported worrying declines in efficacy against human hookworm infections. Although this is not yet cause for alarm, these findings underscore the need for proactive solutions.
Serendipity Strikes Again: The Greyhound Hookworm Mystery
In 2014, a veterinarian informed Dr. Hawdon about a puzzling case: a retired greyhound with a persistent hookworm infection that no treatment could eliminate. Intrigued, he obtained a stool sample and began investigating. What he found was alarming—the hookworms were resistant to all three major drugs used to treat helminthiasis in dogs.
This wasn’t a fluke (literally—flukes are parasitic flatworms, but these were nematodes… 😉). Racing greyhounds, much like farmed sheep, undergo frequent deworming, which over time inadvertently selects for highly resistant worms. As the racing industry declined, many retired greyhounds were adopted into households, unknowingly bringing their “superworms” with them.
Building upon the discovery of multidrug-resistant hookworms in retired greyhounds, Dr. Hawdon's lab is diving deeper into the genetic basis of this resistance. Their research aims to develop better diagnostic tools and treatment strategies to combat these "superworms." By understanding the specific genetic mutations and altered biological pathways in these resistant hookworm populations, the lab hopes to discover more effective control measures and mitigate the spread of resistance.
A Folk Remedy with Modern Potential: The Bitter Melon Discovery
Another unexpected breakthrough in Dr. Hawdon's research came from a master’s student with a passion for ethnobotany, the study of traditional plant-based medicines. While conducting fieldwork in Haiti, she met a voodoo priest who shared knowledge of traditional medicinal plants used for deworming. Curious, she returned with five plant samples for lab testing, and while all showed some level of activity, one stood out: bitter melon.
Intrigued, Dr. Hawdon began growing bitter melon himself, harvesting and processing the plants in his own backyard to further investigate its curative properties. His lab has since uncovered that compounds within the plant disrupt feeding in specific developmental stages of hookworms and is currently working to identify the active components responsible for this effect and understand their mechanisms of action—research which may uncover novel plant-based alternatives for helminthiasis treatments.
The Power of Curiosity and Persistence
Dr. Hawdon’s journey is a testament to the idea that science rewards those who follow their curiosity, even if it means navigating unpredictable paths along the way.
His story demonstrates that great discoveries don't always come from carefully laid plans; sometimes they emerge from a pile of rejection letters, an exhausting job, or an unexpected conversation with a veterinarian friend. The key lies in recognizing opportunities where others see obstacles, and finding value in the unexpected.
After all, as Dr. Hawdon has learned firsthand, serendipity truly does favor the prepared mind.
Additional Information/Resources
Sources:
Fissiha, W., & Kinde, M. Z. (2021). Anthelmintic Resistance and Its Mechanism: A Review. Infection and drug resistance, 14, 5403–5410. https://doi.org/10.2147/IDR.S332378.
McKean, Elise & Grill, Emilia & Choi, Young-Jun & Mitreva, Makedonka & O'Halloran, Damien & Hawdon, John. (2024). Altered larval activation response associated with multidrug resistance in the canine hookworm Ancylostoma caninum. Parasitology. 1-44. 10.1017/S0031182023001385.
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