Anaplasma spp., Coxiella, Babesia and Theileria Infections in Vermipsylla Alakurt Fleas

Vermipsylla alakurt (Siphonaptera: Vermipsyllidae ) is mainly distributed in alpine areas of north-western China, infesting sheep, goat and yaks, causing pruritus, anaemia and losses to animal husbandry. The carriage of vector-borne pathogens by this flea remains unclear. In January 2025, 89 fleas were collected from sheep in the China-Kazakhstan border area of northwest China and identified as V. alakurt by morphology and COII gene sequencing. Multiple genetic markers targeting the genera of Anaplasma , Coxiella , Babesia and Theileria were amplified and sequenced. Among 83 female fleas, Anaplasma ovis ( n = 6), Coxiella burnetii ( n = 37), Babesia sp. ( n = 7), Babesia ovis ( n = 1) and Theileria annulata ( n = 4) were identified. The co-infection of Coxiella burnetii with Anaplasma ovis and Theileria annulata were respectively found. Multiple typical vector-borne pathogens were detected at the first time in V. alakurt fleas. This finding indicates that V. alakurt fleas can carry Anaplasma , Coxiella , Babesia and Theileria in the alpine region of the China-Kazakhstan border.