Isolation of Rickettsia heilongjiangensis (Strain AH-19) from Haemaphysalis longicornis on a Wild Hedgehog in Anhui Province, China.

Background: Spotted fever group rickettsioses, caused by rickettsiae of the spotted fever group, pose a significant zoonotic threat to public health. In endemic areas of Anhui Province, China, the ecology and transmission dynamics of these pathogens remain under investigation. Methods: We isolated a rickettsial strain from Haemaphysalis longicornis ticks collected from a wild hedgehog in the Dabie Mountain area. Molecular identification and phylogenetic analysis were employed to confirm the strain. Pathological examinations of the hedgehog's tissues were conducted to assess the potential impact of the infection. Results: The isolated strain was identified as R. heilongjiangensis strain AH-19. Pathological examination revealed significant tissue alterations, including cellular vacuolization, necrosis, and disarray of tissue architecture. It remains uncertain whether these changes were directly attributable to the rickettsial infection or other factors. Conclusions: The identification of R. heilongjiangensis strain AH-19 in H. longicornis suggests that hedgehogs may serve as reservoir hosts in the Dabie Mountain area.Further research is needed to clarify their role in the ecology and epidemiology of this pathogen, which could inform future public health strategies.