Format

Send to

Choose Destination
Lancet Infect Dis. 2015 Jun;15(6):663-70. doi: 10.1016/S1473-3099(15)70051-4. Epub 2015 Mar 29.

Human infection with a novel tick-borne Anaplasma species in China: a surveillance study.

Author information

1
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
2
Mudanjiang Forestry Central Hospital, Mudanjiang, Heilongjiang Province, China.
3
Shanghai Institute of Medical Genetics, Shanghai Jiaotong University, Shanghai, China.
4
Departments of Pathology and Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA.
5
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China. Electronic address: caowc@bmi.ac.cn.

Abstract

BACKGROUND:

Anaplasma phagocytophilum and Anaplasma ovis cause human infections. We investigated the potential for human pathogenicity of a newly discovered Anaplasma species infecting goats in China.

METHODS:

We collected blood samples from patients with a history of tick bite in the preceding 2 months at Mudanjiang Forestry Central Hospital of Heilongjiang Province from May 1, to June 10, 2014, to detect the novel Anaplasma species by PCR. We inoculated positive samples into cell cultures. We characterised the isolated pathogen by morphological and phylogenetic analyses. We tested serum antibodies by indirect immunofluorescence assay.

FINDINGS:

28 (6%) of 477 patients assessed were infected with the novel Anaplasma species according to PCR and sequencing. We isolated the pathogen in vitro from three patients. Phylogenetic analyses of rrs, gltA, groEL, msp2, and msp4 showed that the pathogen was distinct from all known Anaplasma species. We provisionally nominate it "Anaplasma capra". 22 (92%) of 24 patients with data available had seroconversion or a four-fold increase in antibody titres. All 28 patients developed non-specific febrile manifestations, including fever in 23 (82%), headache in 14 (50%), malaise in 13 (46%), dizziness in nine (32%), myalgia in four (14%), and chills in four (14%). Additionally, ten (36%) of 28 patients had rash or eschar, eight (29%) had lymphadenopathy, eight (29%) had gastrointestinal symptoms, and three (11%) had stiff neck. Five patients were admitted to hospital because of severe disease. Six (35%) of 17 patients with data available had high hepatic aminotransferase concentrations.

INTERPRETATION:

The emergence of "A capra" as a cause of human disease suggests that individuals living in or travelling to endemic regions in northern China should take precautions to reduce their risk of exposure to this novel tick-borne pathogen.

FUNDING:

Natural Science Foundation of China and the US National Institutes of Health.

Comment in

PMID:
25833289
DOI:
10.1016/S1473-3099(15)70051-4
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center