Seroprevalence of Human Granulocytotropic Anaplasmosis in Central and Southeastern China

Human granulocytic anaplasmosis (HGA) is an emerging tick-borne infectious disease. To determine the prevalence of HGA in central and southeastern China, a total of 323 human sera were collected from individuals at high risk for exposure to ticks and animals. The IgG antibody against the etiologic agent of HGA, Anaplasma phagocytophilum was detected with indirect immunofluorescence assay. The results showed that 20% of the tested individuals (64/323) were positive to A. phagocytophilum and that the incidence was higher in male (22%) than female (16%). We concluded that A. phagocytophilum infection was prevalent in central and southeastern China.