title: Rural residents in China are at increased risk of exposure to tick-borne pathogens Anaplasma phagocytophilum and Ehrlichia chaffeensis.
abstract: As emerging tick born rickettsial diseases caused by A. phagocytophilum and E. chaffeensis, anaplasmosis and ehrlichiosis have become a serious threat to human and animal health throughout the world. In particular, in China, an unusual transmission of nosocomial cases of human granulocytic anaplasmosis occurred in Anhui Province in 2006 and more recent coinfection case of A. phagocytophilum and E. chaffeensis was documented in Shandong Province. Although the seroprevalence of human granulocytic anaplasmosis (former human granulocytic ehrlichiosis, HGE) has been documented in several studies, these data existed on local investigations, and also little data was reported on the seroprevalence of human monocytic ehrlichiosis (HME) in China. In this cross-sectional epidemiological study, indirect immunofluorescence antibody assay (IFA) proposed by WHO was used to detect A. phagocytophilum and E. chaffeensis IgG antibodies for 7,322 serum samples from agrarian residents from 9 provinces/cities and 819 urban residents from 2 provinces. Our data showed that farmers were at substantially increased risk of exposure. However, even among urban residents, risk was considerable. Seroprevalence of HGA and HME occurred in diverse regions of the country and tended to be the highest in young adults. Many species of ticks were confirmed carrying A. phagocytophilum organisms in China while several kinds of domestic animals including dog, goats, sheep, cattle, horse, wild rabbit, and some small wild rodents were proposed to be the reservoir hosts of A. phagocytophilum. The broad distribution of vector and hosts of the A. phagocytophilum and E. chaffeensis, especially the relationship between the generalized susceptibility of vectors and reservoirs and the severity of the disease's clinical manifestations and the genetic variation of Chinese HGA isolates in China, is urgently needed to be further investigated.
authors.affiliation: Department of Rickettsiology, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing 102206, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Centers for Disease Control and Prevention of Anhui Province, Hefei 650022, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.affiliation: Centers for Disease Control and Prevention of Henan Province, Zhengzhou 450016, China.
authors.forename: Bianli
authors.initials: B
authors.lastname: Xu
authors.affiliation: Tianjin Center for Disease Control and Prevention, Beijing 300011, China.
authors.forename: Zhilun
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Centers for Disease Control and Prevention of Hainan Province, Haikou 570203, China.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Centers for Disease Control and Prevention of Jilin Province, Changchun 130062, China.
authors.forename: Weiming
authors.initials: W
authors.lastname: Li
authors.affiliation: Centers for Disease Control and Prevention of Zhejiang Province, Hangzhou 310051, China.
authors.forename: Qunying
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Centers for Disease Control and Prevention of Jiangsu Province, Nanjing 210009, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.affiliation: Centers for Disease Control and Prevention of Yunnan Province, Kunming 650022, China.
authors.forename: Litao
authors.initials: L
authors.lastname: Chang
authors.affiliation: Beijing Center for Disease Control and Prevention, Beijing 100013, China.
authors.forename: Xiuchun
authors.initials: X
authors.lastname: Zhang
authors.affiliation: YiLi Prefecture Center for Disease Control and Prevention, Yili 835000, China.
authors.forename: Desheng
authors.initials: D
authors.lastname: Fan
authors.affiliation: Centers for Disease Control and Prevention of Anhui Province, Hefei 650022, China.
authors.forename: Minghua
authors.initials: M
authors.lastname: Cao
authors.affiliation: Centers for Disease Control and Prevention of Henan Province, Zhengzhou 450016, China.
authors.forename: Manli
authors.initials: M
authors.lastname: Bao
authors.affiliation: Tianjin Center for Disease Control and Prevention, Beijing 300011, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Beijing Center for Disease Control and Prevention, Beijing 100013, China.
authors.forename: Zengzhi
authors.initials: Z
authors.lastname: Guan
authors.affiliation: Department of Rickettsiology, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing 102206, China.
authors.forename: Xueqin
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Department of Rickettsiology, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing 102206, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Tian
authors.affiliation: Department of Rickettsiology, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing 102206, China.
authors.forename: Shiwen
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Rickettsiology, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing 102206, China.
authors.forename: Huilan
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Rickettsiology, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing 102206, China ; Shihezi University, Shihezi 832000, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Department of Rickettsiology, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing 102206, China ; Shihezi University, Shihezi 832000, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Centers for Disease Control and Prevention of Anhui Province, Hefei 650022, China.
authors.forename: Yonggen
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Centers for Disease Control and Prevention of Henan Province, Zhengzhou 450016, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Tang
authors.affiliation: Tianjin Center for Disease Control and Prevention, Beijing 300011, China.
authors.forename: Jieying
authors.initials: J
authors.lastname: Yin
authors.affiliation: Centers for Disease Control and Prevention of Hainan Province, Haikou 570203, China.
authors.forename: Shijun
authors.initials: S
authors.lastname: Lao
authors.affiliation: Centers for Disease Control and Prevention of Jiangsu Province, Nanjing 210009, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.affiliation: Centers for Disease Control and Prevention of Yunnan Province, Kunming 650022, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.affiliation: Beijing Center for Disease Control and Prevention, Beijing 100013, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Li
authors.affiliation: YiLi Prefecture Center for Disease Control and Prevention, Yili 835000, China.
authors.forename: Qiyi
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Centers for Disease Control and Prevention of Anhui Province, Hefei 650022, China.
authors.forename: Yonglin
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Centers for Disease Control and Prevention of Hainan Province, Haikou 570203, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Huang
mesh_terms: D000328:Adult; D041081:Anaplasma phagocytophilum; D000818:Animals; D001096:Arachnid Vectors; D002417:Cattle; D002681:China / Q000453:epidemiology; D004285:Dogs; D018469:Ehrlichia chaffeensis; D016873:Ehrlichiosis / Q000453:epidemiology* / Q000276:immunology / Q000635:transmission*; D005260:Female; D006041:Goats; D006736:Horses; D006801:Humans; D008297:Male; D011817:Rabbits; D016036:Seroepidemiologic Studies; D012756:Sheep; D017282:Tick-Borne Diseases / Q000453:epidemiology* / Q000276:immunology / Q000635:transmission*; D013987:Ticks