Ropuia Hun, Ramliana Van, Pautu Lalfakzuala, Rosangkima Gabriel, Vanlalawmpuii Ralte, Ramdinthara Zo
Department of Life Sciences, Pachhunga University College, Aizawl, Mizoram, 796005, India.
Department of Zoology, Pachhunga University College, Aizawl, Mizoram, 796005, India.
BMC Vet Res. 2025 Mar 8;21(1):158. doi: 10.1186/s12917-025-04629-8.
BACKGROUND & OBJECTIVES: Orientia tsutsugamushi, a bacterial pathogen of scrub typhus, is transmitted to humans through the bite of infected chigger mites, and rodents are the natural hosts of the disease vector. The traditional practices of the tribal ethnic groups (Mizo) of Mizoram state such as capturing and consumption of rat meat collected from the agricultural fields could be one source of vector-disease transmission route. The present study aimed to detect and identify the pathogen of scrub typhus from vectors collected from rice field rats which were captured by farmers for meat consumption purposes.
One hundred and fifty-six freshly captured rice field rats were examined for ectoparasites. Detection and genotyping of O. tsutsugamushi from ectoparasites were done by real-time PCR and conventional PCR using species-specific primers. Rodents and ectoparasites were identified down to the species level using morphological and molecular techniques.
Rice field rats were identified as Rattus tanezumi and Rattus nitidus. A total of 7973 trombiculid mites collected from 156 rats were identified as Leptotrombidium deliense, Leptotrombidium fletcheri, and Leptotrombidium chiangraiensis. Of these, 26 pools of L. deliense and 15 pools of L. fletcheri tested positive for O. tsutsugamushi, and the O. tsutsugamushi detected belongs to Kato and Karp-related genotypes.
INTERPRETATION & CONCLUSION: The present study reported the presence of O. tsutsugamushi-infected chigger mites in the captured rats (R. tanezumi and R. nitidus). Direct contact with the rats as a result of rat-eating habits may correspond to the high incidence rate of scrub typhus cases in Mizoram. Preventive measures are crucial for the control of scrub typhus disease in Mizoram.
恙虫病东方体是恙虫病的病原菌，通过感染恙螨叮咬传播给人类，而啮齿动物是该病媒介的自然宿主。米佐拉姆邦部落族群（米佐族）的传统习俗，如捕捉并食用从农田捕获的鼠肉，可能是媒介 - 疾病传播途径的一个来源。本研究旨在从农民为食用而捕获的稻田鼠身上采集的媒介中检测和鉴定恙虫病的病原体。
对156只新捕获的稻田鼠进行体外寄生虫检查。使用物种特异性引物，通过实时PCR和常规PCR对体外寄生虫中的恙虫病东方体进行检测和基因分型。利用形态学和分子技术将啮齿动物和体外寄生虫鉴定到物种水平。
稻田鼠被鉴定为黄胸鼠和针毛鼠。从156只鼠身上共采集到7973只恙螨，分别鉴定为地里纤恙螨、弗氏纤恙螨和清莱纤恙螨。其中，26组地里纤恙螨和15组弗氏纤恙螨检测出恙虫病东方体呈阳性，检测到的恙虫病东方体属于与Kato和Karp相关的基因型。
本研究报告了在捕获的鼠（黄胸鼠和针毛鼠）中存在感染恙虫病东方体的恙螨。由于食鼠习惯而与鼠直接接触可能与米佐拉姆邦恙虫病的高发病率有关。预防措施对于米佐拉姆邦恙虫病的控制至关重要。
