Why Are Zoonotic Diseases Becoming a Bigger Risk?

As of September 9, 2025, the Worldometer listed the human global population as 8.3 billion people (1). This population growth means that humans will be living and working in previously uninhabited or minimally disturbed environments, increasing interactions between humans, domestic animals, wildlife, and their pathogens. This intensifying human-animal interface heightens the risk of zoonotic disease transmission, where pathogens cross species barriers (from wildlife to domestic livestock or from wildlife to humans), potentially leading to outbreaks and even pandemics.

How Do Urbanization and Climate Change Amplify Zoonotic Threats?

Urbanization, habitat disruption, and climate change further exacerbate these risks by altering ecosystems and facilitating the spread and emergence of vector-borne and zoonotic diseases. Understanding and addressing these threats requires robust surveillance, effective diagnostics, and proactive strategies to prevent and mitigate disease emergence and spread.

In urban areas, public health officials are already using wastewater to monitor known pathogens and identify “hot spots” of activity to predict increases in illness within local populations (2). Animal shelters are another place where there is an opportunity to monitor for emerging infectious diseases that could affect domestic pet animals.

Could Animal Shelters Serve as Early Warning Systems for Zoonotic Diseases?

In a recent paper, Kelly et al. (3) describe their study to evaluate the prevalence of the parasitic nematode, Onchocera lupi among a population of dogs in an urban animal shelter. The nematode primarily infects wild and domestic canines as well as cats and humans. Clinical infections are associated with ocular disease, but subclinical cases are challenging to recognize. Understanding the prevalence of the parasite in urban areas, particularly in shelter populations that typically go unmonitored, provides critical information for public health surveillance, veterinary practice and disease control strategies.

In the study reported by Kelly et al., they developed a qPCR assay that was optimized to detect O. lupi DNA from skin snips. Snips were collected from 404 dogs and genomic DNA was extracted from the samples using the Maxwell® RSC Tissue DNA Kit and the Maxwell® RSC 48 Instrument and analyzed using both the new probe-based qPCR assay and a conventional PCR followed by Sanger sequencing. After optimization, the qPCR assay detected a 1.9% prevalence of O. lupi compared to a 1.6% prevalence detected by conventional PCR, suggesting it was a more sensitive assay. However, according to the authors of the study, even the 1.9% prevalence could be an underestimation.

How Promega Supports One Health
The One Health approach recognizes that human, animal, and environmental health are deeply connected. At Promega, we support this integrated perspective by providing sensitive, reliable technologies that enable early detection, tracking, and mitigation of zoonotic diseases. From sample prep to detection, our tools are designed to help scientists, veterinarians, and public health professionals work across disciplines to protect communities.

Explore how Promega enables One Health Solutions

Summary

This study detected nearly 2% prevalence of O. lupi in shelter dogs from an urban setting, that would have likely gone undetected without monitoring this population sample using a highly sensitive assay. Understanding the prevalence of this and other pathogens in urban areas, particularly in shelter populations that typically go unmonitored, can provide critical information for public health surveillance, veterinary practice, and disease control strategies.

Additional Promega Product Used in This Study

GoTaq® Green Master Mix

Additional Resources

For more information consider viewing our webinar (live on September 25, 2025 or on-demand afterward): Unmasking Emerging Parasites: Diagnostics for One Health Surveillance

Literature Cited

1. World Population Clock. https://www.worldometers.info/world-population/ (accessed 9/9/2025).
2. Lee, J. (2021) From Drug Use to Viral Outbreaks, How Monitoring Sewage Can Save Lives – Promega Connections   (accessed 9/11/2025)
3. Kelly, M.A. et al. (2025) Prevalence of Onchocerca lupi in shelter dogs from an endemic region of the Southwester USA. Parasites & Vectors 18:335.

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Michele Arduengo, PhD

Supervisor, Digital Marketing Program Group at Promega Corporation

Michele earned her B.A. in biology at Wesleyan College in Macon, GA, and her PhD through the BCDB Program at Emory University in Atlanta, GA where she studied cell differentiation in the model system C. elegans. She taught on the faculty of Morningside University in Sioux City, IA, and continues to mentor science writers and teachers through volunteer activities. Michele manages the digital marketing program team at Promega.

Latest posts by Michele Arduengo, PhD (see all)

• What Shelter Dogs Can Tell Us About Emerging Zoonotic Diseases - October 2, 2025
• Developing an Experimental Model System to Understand the Tumor Microenvironment of Melanoma Brain Metastases - September 4, 2025
• IL-6/STAT3-Regulated Long Non-Coding RNA Is Involved in Colorectal Cancer Progression - July 1, 2025