Background: Visceral leishmaniasis (VL) is endemic in western China, and becoming an important public health concern. Infected dogs are the main reservoir for Leishmania infantum, and a potential sentinel for human VL in endemic areas. In the present study we investigated the prevalence of Leishmania DNA in dogs from Wenchuan, Heishui and Jiuzhaigou County in Sichuan Province, southwestern China, which are important endemic areas of zoonotic VL, detected by real time PCR. The results will help to design control strategies against visceral leishmaniasis in dogs and humans. Results: The overall prevalence of Leishmania DNA in dogs was 24.8% (78/314) in Sichuan Province, with the positive rate of 23.5% (23/98) in Wenchuan County, 28.2% (20/71) in Heishui County, and 24.1% (35/145) in Jiuzhaigou County, and no significant difference was observed among the three counties (P > 0.05). The dogs were further allocated to different groups based on sexes, ages and external clinical symptoms. The logistic regression analysis revealed that a higher prevalence was found in older and external symptomatic dogs, compared to that of younger and asymptomatic dogs (P < 0.05). Conclusions: The results revealed that L. infantum infection in dogs is widespread in Sichuan Province, southwestern China, which has a public health significance, due to its contribution to the transmission of the infection to humans by sandflies. It is necessary to take measures, including treatment or eradication of infected dogs, to control canine leishmaniasis, which could be helpful to reduce human VL in this area.

Trillium camschatcense, a plant renowned for its ecological and medicinal value, is predominantly found in the temperate forests of East Asia. However, its habitat is increasingly threatened from climate change, habitat fragmentation, and intensified human activities. In this study, the Maxent (Maximum Entropy) model was used to assess the current ecological suitability of T. camschatcense based on historical climate data (1970–2000), and further simulate its potential distribution shifts under multiple future climate change scenarios to predict long-term habitat variation trends across northeast China. All modeling and spatial mapping analyses were performed using MaxEnt and ArcGIS 10.8.1 software. Drawing upon 93 known distribution points and 26 pertinent environmental variables covering climate, soil, and elevation, we built species distribution models for both present and future periods to pinpoint the crucial environmental factors influencing its distribution. Our findings revealed that elevation, soil nitrogen content, seasonal temperatures, annual precipitation, mean temperature during the coldest quarter, and mean diurnal temperature range were the primary factors influencing the distribution of T. camschatcense. Notably, highly suitable habitats were predominantly concentrated in Baishan City and the southwestern region of Yanbian Korean Autonomous Prefecture in Jilin Province. This insight offers valuable scientific guidance for the conservation planning, sustainable utilization, and potential introduction and cultivation of T. camschatcense. Furthermore, targeted conservation strategies can help identify climate refugia and protect climatically stable habitats for the long-term persistence and resilience of the species under continuous global warming.