Breakthrough DNA tool could help prevent tropical disease outbreaks
Baku, November 12, AZERTAC
A new DNA-based test is giving scientists and public health officials an unprecedented way to track leishmaniasis, a parasitic disease affecting humans and animals, according to TPS-IL. Researchers in Israel have developed a method that identifies sand fly species, detects Leishmania parasites, and determines the source of the insects’ blood meals from a single specimen, opening new possibilities to contain the disease.
Leishmaniasis is a parasitic disease caused by protozoa of the genus Leishmania. It is transmitted primarily through the bite of infected female sand flies. The disease is considered a “neglected tropical disease” by the World Health Organization (WHO) because it affects millions worldwide, mostly in poor or rural regions, yet receives limited global attention compared to malaria or dengue.
Depending on where the parasite infects the body, leishmaniasis can cause potentially disfiguring skin sores and severe tissue destruction in the nose and throat. Its most dangerous form infects internal organs such as the spleen, liver, and bone marrow, and is fatal if untreated.
The study, led by Prof. Gad Baneth of the Koret School of Veterinary Medicine at Hebrew University of Jerusalem in collaboration with the Laboratory of Entomology at the Israeli Ministry of Health, analyzed nearly 2,000 sand flies across Israel. Using high-resolution melting (HRM) PCR, the team identified twelve sand fly species, four Leishmania species — L. major, L. tropica, L. infantum, and L. donovani — and twenty-five animal blood sources, including domestic cats, cows, hyraxes, and hares.
“By uniting veterinary and public health surveillance, we can now trace the parasite’s journey from animal to insect to human with unprecedented precision,” Baneth said. “This method transforms how we monitor zoonotic diseases in the field.”
The HRM PCR technique is a major advance because it can perform three tasks simultaneously from a single specimen: determine the sand fly species, detect Leishmania infection, and identify the blood meal source. Previous methods required multiple tests and were slower, more costly, and less reliable. The new system achieved a 96.7 percent success rate in identifying the host animal, offering a near-complete picture of transmission pathways.
The study revealed clear ecological patterns. Vectors carrying L. major and L. donovani were concentrated in Israel’s arid southern regions, while L. tropica and L. infantum were more common in the center and north. Some sand fly species were also found outside their historically recognized habitats, suggesting environmental or climatic changes may be expanding transmission zones. Researchers also found that domestic cats, hyraxes, hares, and cows accounted for more than half of all blood meals, highlighting the critical role animals play in sustaining the disease.
Knowing which sand fly species are present and where they are can help public health authorities map risk areas and predict outbreaks. By simultaneously detecting Leishmania parasites in the sand flies, the method shows which insects are actively carrying the disease.
Moreover, the HRM method can pinpoint the blood meal source of the sand fly, revealing which animals are sustaining the disease. This information can allow veterinarians and wildlife managers to target specific animals for monitoring or interventions. By combining data on sand fly species, parasite presence, and animal hosts, authorities can design targeted interventions such as focused insecticide spraying, treatment of domestic reservoirs, or community awareness campaigns in high-risk areas.
The research was published in the peer-reviewed journal, PLOS Neglected Tropical Diseases.
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