In Reply HGA was first discovered by Dr Yan Liu at the Anhui Provincial Center for Diseases Control and Prevention (CDC) in China between 2006 and 2007 by detection of A phagocytophilum 16S RNA gene sequences and antibodies in the blood samples of a cluster of patients. At that time Liu’s laboratory had never handled A phagocytophilum DNA or the organism, making laboratory contamination unlikely. After discovery of A phagocytophilum in the patients’ samples, the samples were transferred to the Rickettsial Laboratory in the Chinese CDC in Beijing for further testing. The Chinese CDC also detected A phagocytophilum DNA and antibodies in the samples and conducted a detailed epidemiological investigation of the cluster of patients. The laboratory results of the Anhui CDC and the Chinese CDC met the criteria for diagnosis of HGA including immunofluorescence assay seroconversion and positive A phagocytophilum PCR in blood.1 Based on detection of A phagocytophilum DNA and antibodies in the patients’ samples and without knowledge of other pathogens existing in the samples, A phagocytophilum was considered the cause of the epidemic and the results published in JAMA.
Liu Y, Yu X. Human Granulocytic Anaplasmosis and Lyme Disease—Reply. JAMA. 2016;316(1):99. doi:10.1001/jama.2016.4295