我国新发蜱传立克次体感染状况调查及传播规律研究

Tick-borne spotted fever group rickettsia (SFGR) is a neglected zoonotic disease. The delayed treatment due to misdiagnosis can cause multi-functional failure or even death of the patient. Some rickettsiae species are even listed as potential bioterrorism agents, thus posing a potential threat on our country biosafety. Our group has identified four novel SFGR species emerging in China during past five years. The clinical manifestations were all different from previous reports, thus we should pay attention to the prevention and control of these new rickettsiosis. Based on the previous research, the current project will continue SFGR surveillance on important ticks from different regions and on tick-bite patients enrolled in sentinel hospitals, and especially work on the bacterial isolation and identification as to characterize its genomic and biological features and understand its pathogenicity against human beings. On the other hand, we will study on the transovarial and transstadial transmission of the novel SFGR strains to understand the vector competency. More importantly, this research will assess the microbiome of diverse tick species, different life stage of the ticks (larvae, nymph, adult) and salivary glands of the tick to understand the correlation between the tick microbiome and the novel SFGR transovarial, transstadial and oral transmission, which will likely reveal new insights and spawn new paradigms to control tick-borne SFGR transmission. Our study aims to provide the scientific data for prevention and control of novel spotted fever group rickettsiosis.

蜱传立克次体病是一类被忽视的自然疫源性疾病，如因误诊未及时治疗，可造成多器官功能衰竭甚至死亡。立克次体作为一种生物战剂，对我国生物安全具有潜在威胁。本课题组近5年共发现了4种新发立克次体病，临床表现与以往报道都不尽相同，对我国立克次体的防控提出了新的挑战。本项目在前期工作基础上继续开展我国重要蜱种和哨点医院蜱咬病人的新发立克次体感染状况调查，着重病原体分离鉴定，阐明新发立克次体生物学特征及其对人类的致病性。另外，了解新发立克次体在不同蜱种的传播效能，掌握其优势媒介蜱种，明确不同蜱种在新发立克次体病传播中的作用。更重要的是探索不同蜱种、不同虫体（幼蜱、若蜱、成蜱）及蜱唾液腺微生物种群多样性与新发立克次体经卵、经期传播及经口传播之间的相互关系，为从微生物种群角度防控立克次体的传播提供基础数据，为预防、控制潜在新发立克次体病提供科学依据。

蜱传立克次体病是一类被忽视的自然疫源性疾病。立克次体作为一种生物战剂，对我国生物安全具有潜在威胁。本项目开展我国重要蜱种和哨点医院蜱咬病人的新发立克次体感染状况调查，了解新发立克次体在不同蜱种的传播效能，探索微生物种群在立克次体传播中的作用。按计划在10个省市采集约1万只蜱，涉及29个蜱种。分离鉴定了3种新发立克次体，分别为“Rickettsia cangshanensis”，"R. erhaii”和Candidatus Rickettsia longicornii。然而在我国北方和南方的哨点医院中尚未发现此3种立克次体的感染病例。明确了2种致病性立克次体Candidatus Rickettsia tarasevichiae 和R. raoultii在2个重要蜱种，全沟硬蜱和森林革蜱的传播效能。发现对于立克次体感染的种群来说，微生物组构成在整个垂直传播过程中相对稳定，但是对于立克次体非感染的种群来说，微生物组构成随着传播过程而逐渐下降，上述数据与结果为预防、控制潜在新发立克次体病提供科学依据。