title: Epidemiological, clinical, and laboratory characteristics of 48 cases of "Babesia venatorum" infection in China: a descriptive study.
abstract: BACKGROUND
  Human babesiosis is an emerging zoonosis. "Babesia venatorum" has been identified in only four asplenic men and a child so far. We aimed to describe the epidemiological, clinical, and laboratory characteristics of a series of cases with "B venatorum" infection identified in a sentinel hospital in China.
  
  
  METHODS
  We recruited participants with a recent tick bite at Mudanjiang Forestry Central Hospital, Heilongjiang province, China. Cases were diagnosed through PCR followed by sequencing, microscopic identification, or isolation by animal inoculation, or both.
  
  
  RESULTS
  48 individuals (30 women or girls; median age 45 years, range 7 months to 75 years) with "B venatorum" infection were identified. 32 of these individuals were confirmed cases and 16 were probable cases. None of the 48 cases had received a blood transfusion or had a splenectomy. Geographically, cases were distributed diffusely throughout the hospital catchment area. Of the 32 confirmed cases, 21 (66%) presented with a fever, 13 (41%) with a headache, 12 (38%) with myalgia or arthralgia, and three (9%) with chills. 14 (44%) patients had fatigue, eight (25%) had dizziness, and eight (25%) had hypersomnia. Six (19%) patients had an erythematous non-pruritic rash around the tick-bite site and two (6%) had lymphadenopathy. Seven (22%) and four (13%) patients had anaemia and thrombocytopenia, respectively, and seven (50%) of 14 patients with confirmed infection had increased hepatic transaminase concentrations. In the confirmed cases, concentrations of intercellular adhesion molecule 3 (p<0·001), P-selectin (p<0·05), and platelet endothelial cell adhesion molecule 1 (p<0·001) were significantly reduced, whereas tumour necrosis factor α (p<0·01) and vascular cell adhesion molecule 1 (p<0·001) were significantly increased.
  
  
  CONCLUSIONS
  "B venatorum" infection should be included in the differential diagnosis of patients with a tick-exposure history in areas where this pathogen has previously been identified in ticks or people.
  
  
  BACKGROUND
  Natural Science Foundation of China and Mega-Project for Infectious Diseases.
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Jia-Fu
authors.initials: JF
authors.lastname: Jiang
authors.affiliation: Mudanjiang Forestry Central Hospital, Mudanjiang, Heilongjiang Province, China.
authors.forename: Yuan-Chun
authors.initials: YC
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Rui-Ruo
authors.initials: RR
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.affiliation: Mudanjiang Forestry Central Hospital, Mudanjiang, Heilongjiang Province, China.
authors.forename: Qiu-Bo
authors.initials: QB
authors.lastname: Huo
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Bao-Gui
authors.initials: BG
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Na
authors.initials: N
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Ya-Wei
authors.initials: YW
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Liu
authors.affiliation: Mudanjiang Forestry Central Hospital, Mudanjiang, Heilongjiang Province, China.
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Xue-Bing
authors.initials: XB
authors.lastname: Ni
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Liu
authors.affiliation: Mudanjiang Forestry Central Hospital, Mudanjiang, Heilongjiang Province, China.
authors.forename: Yu-Dong
authors.initials: YD
authors.lastname: Song
authors.affiliation: Mudanjiang Forestry Central Hospital, Mudanjiang, Heilongjiang Province, China.
authors.forename: Nan-Nan
authors.initials: NN
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.affiliation: Mudanjiang Forestry Central Hospital, Mudanjiang, Heilongjiang Province, China.
authors.forename: Tie
authors.initials: T
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China. Electronic address: caowc@bmi.ac.cn.
authors.forename: Wu-Chun
authors.initials: WC
authors.lastname: Cao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001403:Babesia / Q000302:isolation & purification*; D001404:Babesiosis / Q000175:diagnosis / Q000453:epidemiology* / Q000469:parasitology / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D019411:Clinical Laboratory Techniques; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D064927:Tick Bites / Q000150:complications; D017282:Tick-Borne Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000469:parasitology / Q000473:pathology*; D055815:Young Adult