, and in fleas from the long-tailed ground squirrel () in northwestern China.

Fleas are known to be vectors for a variety of pathogens in veterinary medicine. However, no information is available on the presence of and Trypanosomatidae in fleas of the long-tailed ground squirrel (LTGR, ). The present study shows detection of these pathogens in LTGR fleas. During 2022-2023, a total of 396 fleas were collected from 91 LTGRs in 4 alpine regions of Xinjiang Uygur Autonomous Region (northwestern China) and grouped into 54 flea pools. Flea species were identified according to morphological characteristics and molecular data. In addition, all flea samples were analyzed for with amplification and sequencing of a 380-bp part of the gene and Trypanosomatidae with targeting the (850-bp) and (820-bp) genes. The flea species included (203), (49), and (144). Of 54 flea pools, seven (12.96%) tested positive for , and three (5.56%) were positive for Trypanosomatidae. Based on BLASTn and phylogenetic analyses, i) in and , and in were identified. Interestingly, a new haplotype within the species was discovered in ; and ii) was confirmed in and in . Two species and two Trypanosomatidae members were discovered for the first time in fleas from LTGRs. This study broadens our understanding of the geographic distribution and potential vectors for and Trypanosomatidae.