Leishmaniasis, a parasitic disease transmitted by sand flies, has long posed significant challenges to veterinarians and public health experts. The disease, prevalent among humans and animals in Israel and many other parts of the world, involves a complex transmission cycle with numerous sand fly species and a variety of wild and domestic reservoirs.
A groundbreaking study led by Prof. Gad Baneth from the Koret School of Veterinary Medicine at the Hebrew University of Jerusalem, in collaboration with the Laboratory of Entomology at the Israeli Ministry of Health, has introduced a novel approach to tracking and understanding this complexity. Published in PLOS Neglected Tropical Diseases, the research unveils a high-resolution melting (HRM) PCR-based technique capable of identifying sand fly species, detecting Leishmania parasites, and pinpointing the source of the insect’s blood meal from a single specimen.
Revolutionizing Disease Surveillance
This innovative molecular method replaces traditional, time-consuming techniques with a fast, cost-effective diagnostic system offering near-complete accuracy. “By uniting veterinary and public health surveillance, we can now trace the parasite’s journey from animal to insect to human with unprecedented precision,” states Prof. Baneth. “This method transforms how we monitor zoonotic diseases in the field.”
The research team analyzed nearly 2,000 sand flies collected across Israel, identifying 12 distinct sand fly species, four species of Leishmania—L. major, L. tropica, L. infantum, and L. donovani—and 25 different blood meal sources, ranging from domestic cats and cows to rock hyraxes and hares. Their findings reveal distinct ecological zones: L. major and L. donovani vectors dominated the arid southern regions, while L. tropica and L. infantum were more common in the center and north.
Environmental Shifts and Expanded Habitats
Interestingly, sand fly species were also found outside their historically recognized habitats, suggesting environmental or climatic shifts that may be expanding transmission zones. The HRM system achieved a 96.7% success rate in identifying blood meal sources, a vital advance for One Health studies that bridge veterinary and human epidemiology. Domestic cats, hyraxes, hares, and cows accounted for more than half of all identified blood meals, underscoring the crucial role of animals in sustaining the disease’s life cycle.
Leishmaniasis is both a veterinary and human health concern, affecting dogs, cats, and wildlife reservoirs alongside people. The HRM technology’s ability to distinguish between species and trace infection patterns enables earlier intervention and targeted control strategies. For veterinarians, it provides a diagnostic window into infection ecology, helping identify animal hosts that serve as silent reservoirs and improving outbreak prediction.
Implications for Global Health
Prof. Baneth notes that “rapid and precise identification of infected vectors and reservoir hosts allows us to anticipate emerging foci and protect both animal and human populations.” This pioneering molecular toolkit not only enhances Israel’s surveillance of vector-borne diseases but also offers a model adaptable to other endemic regions. By merging molecular diagnostics with field ecology, the study marks a significant step forward in the fight against neglected tropical diseases that cross the animal-human divide.
The announcement comes as global health organizations emphasize the importance of integrated approaches to managing zoonotic diseases. The HRM technique could provide a template for similar strategies in other regions grappling with vector-borne diseases, potentially transforming public health responses worldwide.
As the world continues to grapple with the impacts of climate change and habitat alteration, the ability to swiftly and accurately track disease vectors and reservoirs becomes increasingly critical. This development follows a growing recognition of the interconnectedness of ecosystems, human health, and animal health, reinforcing the need for comprehensive surveillance systems.
Looking forward, the research team aims to refine the HRM technique further and explore its application in other vector-borne diseases. The move represents a significant advancement in the ongoing battle against leishmaniasis and other similar diseases, offering hope for more effective control and prevention strategies in the future.
