Subcutaneous dirofilariasis, caused by the parasite Dirofilaria repens, has long been overlooked in veterinary circles—especially outside endemic regions. But global movement and climate change are pushing this zoonotic threat into new territories, including the United States. Dr. Iuliia Dakhno, a Ukrainian veterinary parasitologist, has developed an ELISA-based diagnostic tool that could change how we detect and manage this emerging infection. In this exclusive interview, she explains the science behind the test and why it matters now more than ever.
Why should the U.S. care about a European parasite?
Because Dirofilaria repens is no longer just a ‘European problem.’ The parasite spreads via mosquitoes—especially species like Aedes albopictus and Culex pipiens, which are already present in North America. With climate change and international pet travel, we’re seeing this parasite expand its range rapidly. While the U.S. is more familiar with heartworm (D. immitis), D. repens causes subcutaneous nodules and can affect humans too. A recent suspected human case in the U.S. (reported in 2023) only confirms the urgency of surveillance.
What clinical signs should veterinarians watch for?
Unlike heartworm, D. repens doesn’t settle in the heart. Instead, it causes localized swellings, nodules, or skin irritations—usually without pain. In some cases, the worms can migrate under the skin, making detection challenging. These subtle signs are easy to miss, especially in asymptomatic dogs.
How is this parasite transmitted?
Transmission occurs via mosquito vectors. After a mosquito bites an infected host, it carries the larval stage of D. repens, which matures and is transmitted during the next blood meal. This cycle is silent, and with urban mosquito populations increasing, the risk of unnoticed spread grows.
What challenges exist in diagnosing this parasite?
The main issue is that D. repens often goes undetected in dogs. In early stages, there are no visible signs, and microfilariae (larvae in the blood) may be absent. Standard blood smear microscopy isn’t enough. That’s why we needed a better diagnostic tool—something that could detect infection at early or occult stages, even without symptoms. That’s where ELISA comes in.
How did you develop the ELISA test?
I began by collecting adult parasites from subcutaneous tissues of infected dogs in endemic regions of Ukraine. This work was part of my dissertation research, and I conducted all laboratory stages, including antigen purification and test validation, myself.
How accurate is the test?
It demonstrated 76.5% sensitivity and 80.6% specificity. That’s strong performance, especially for a screening tool. While some cross-reactivity with D. immitis was observed, it remained minimal and manageable for practical diagnostics.
How prevalent is D. repens in Ukraine and other regions you’ve studied?
In my fieldwork across Ukraine, especially in Poltava and Sumy, I found infection rates ranging from 6% to 19% depending on the region. Interestingly, mixed infections with both D. repens and other helminths were common. This shows how important it is to have tests that can specifically distinguish between them.
Could this ELISA be used in field or shelter settings?
Yes, and that’s what makes it valuable. Portable versions could be used in shelters, border control, or by field veterinarians. Early detection prevents spread—especially in high-traffic areas like rescues or transport hubs.
What’s next for your research?
I’m working on simplifying the ELISA protocol even more and turning it into a rapid format—something closer to a point-of-care test. I’m also collaborating with experts on the potential of integrating such diagnostics into routine preventive panels in high-risk areas.
Final thoughts?
D. repens is a silent threat that could easily be missed until it’s too late. But we can be proactive. With proper tools and awareness, we can protect both animals and humans from this emerging zoonotic risk.
Meet Abby, a passionate health product reviewer with years of experience in the field. Abby's love for health and wellness started at a young age, and she has made it her life mission to find the best products to help people achieve optimal health. She has a Bachelor's degree in Nutrition and Dietetics and has worked in various health institutions as a Nutritionist. Her expertise in the field has made her a trusted voice in the health community. She regularly writes product reviews and provides nutrition tips, and advice that helps her followers make informed decisions about their health. In her free time, Jane enjoys exploring new hiking trails and trying new recipes in her kitchen to support her healthy lifestyle.
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