Siyu Gao1 *, Lingfeng Li2 *, Xiaolin Zhou,1 Xiangcheng Dai,1 Lu Lu,1 Yandong Chen,1 Jing Han,1 Xiaoli Huang,1 Qian Xiao,1 Huiqing He,3 Qiang Liu1 1Yichang Central People’s Hospital, The First College of Clinical Medical Science, China Three Gorges University, Yichang, Hubei, People’s Republic of China; 2Department of Critical Care Medicine, Dongguan Institute of Respiratory and Critical Care Medicine, Dongguan People’s Hospital, Dongguan, Guangdong, People’s Republic of China; 3Centers for Disease Control and Prevention, Yichang, Hubei, People’s Republic of China*These authors contributed equally to this workCorrespondence: Qiang Liu, Email stellarray@126.comBackground: Severe complications may cause a fatal or disabling outcome in patients with Rickettsia japonica infection but are poorly understood.Methods: We identified 11 patients with only Rickettsia japonica infection with metagenomics next generation sequencing (mNGS) during April to November 2021 at Yichang Central People’s Hospital, China. Clinical data were obtained through review of medical records.Results: Most patients realized that they had symptoms about one or two days after being bitten. Fever (91%), pulmonary effusion (91%), rash or erythema (100%), abnormal urine (100%), neutropenia (100%), lymphopenia (100%), and thrombocytopenia (100%) were the most common clinical signs. Six severely ill patients were admitted to the intensive care unit and five had mild symptoms. Systemic manifestations such as vomiting (83%), neurological manifestations (100%), and disseminated intravascular coagulation (100%) were more frequently observed in the severe cases, 33.3% of whom developed purpura fulminans requiring amputation or skin graft, and 16.6% died two days after admission. Some patients experienced sequelae.Conclusion: Our study found that patients with critical Rickettsia japonica infection complicating disseminated intravascular coagulation had high risk of poor outcome.Keywords: Rickettsia japonica, Japanese spotted fever, infection, tick, disseminated intravascular coagulation, purpura fulminans
