Zoonotic leishmaniasis in China: Current status and challenges to elimination

Leishmaniasis is expanding worldwide along with sand fly vectors. In China, particular challenges arise from its broad climatic and ecological gradients, the diversity of phlebotomine sand fly species, and numerous potential mammalian and reptilian hosts. Two ecological types of visceral leishmaniasis (VL) are recognized: anthroponotic VL (AVL) caused by Leishmania donovani and zoonotic VL (ZVL) caused by Leishmania infantum, which is subdivided into mountain-type (MT-ZVL) where dogs are the main reservoir, and desert-type (DT-ZVL) with uncertain reservoirs. Over the last decade, VL has re-emerged in central and northern regions of China, with increasing MT-ZVL notifications and evidence of canine infections in geographical areas where transmission had not previously been reported. This review synthesizes three decades of literature on canine leishmaniasis (CanL) and its vectors in China, focusing on domestic and wild reservoirs in the maintenance of zoonotic VL. Molecular studies reveal substantial genetic heterogeneity within the L. donovani complex and frequent discordance between single-locus markers (e.g., ITS1, cytb) and higher-resolution approaches (MLST/MLMT). Leishmania infection in dogs is most common in western foci, with high detection rates ranging from 24.8% to 77.2%, especially in Gansu and Sichuan Provinces, where subclinical infections predominate. Also, evidence of co-circulating unclassified Leishmania lineages related to Sauroleishmania complicates diagnosis and surveillance. Vector ecology, including the endophilic/exophilic behavior of Phlebotomus chinensis and the role of P. sichuanensis at high altitudes, overlaps with environmental change, dog management, and increasing stray dog populations, thereby amplifying transmission risk. Based on available data, dog culling is ineffective for long-term control of CanL due to poor diagnostics, rapid replacement of culled dogs, and ecological complexity. Conversely, vector control and bite prevention, using topical pyrethroid repellents (collars, spot-on pipettes) and possibly oral isoxazolines, should be implemented in dogs as control measures after appropriate field evaluation. Key gaps include insufficient canine surveillance and validation of diagnostic tools, as well as incomplete characterization of wildlife reservoirs. Strengthened One Health surveillance, integrating genomics, vector studies, and reservoir investigations, is essential to guide targeted control and predict future spread.

The PubMed, Scopus, Google Scholar, and Web of Science databases were searched from 1950 to 2025 for peer-reviewed publications reporting the genetic diversity of Leishmania species, the epidemiology and prevalence of zoonotic VL and CanL, and trends in their spatial and temporal distribution in China for this narrative review. Three search strings were employed in these databases to; (1) identify reservoir host and sand fly vectors for leishmaniasis in China, (2) identify the epidemiology (risk factors, re-emergence, trends) and control and prevention of leishmaniasis in China, (3) identify the diversity of Leishmania species in China. The protocols for database searches are provided in the Supporting Information. The China National Knowledge Infrastructure database was additionally searched to obtain Leishmania prevalence data in animals. Data were extracted from articles published in English and Chinese. After removal of duplicates, abstracts of 865 articles were screened for relevance, from which 279 full-text articles were reviewed to extract relevant information. Articles were included for final review (n = 129) if they contained data on molecular and/or serological Leishmania infection-rate data in dogs, the genetic diversity of Leishmania species in China, computational trends in VL, reservoir hosts for Leishmania species and, sand fly vectors in China.