Viral shedding pattern of severe fever with thrombocytopenia syndrome virus in severely ill patients:A Prospective, Multicenter Study

Abstract

Background. Severe fever with thrombocytopenia syndrome (SFTS) is spreading rapidly in Asia. The pathway of SFTS virus shedding from patient and specific use of personal protective equipments (PPEs) against viral transmission have rarely been reported. Methods. A multicenter cohort study was performed to determine SFTS virus (SFTSV) level from blood, throat swabs, fecal/ anal swabs, urine and bedside environment swabs of SFTS patients by qRT-PCR. PPEs were applied in healthcare workers based on the pathway of SFTSV shedding and occurrence of hemorrhagic signs in patients. Results. A total of 189 SFTSV-confirmed patients were included in the study, 54 patients died (case fatality rate, 28.57%). Positive SFTSV in throat swabs (T-SFTSV), fecal /anal swabs (F-SFTSV) and urine (U-SFTSV) were detected in 121 (64.02%), 91 (48.15%) and 65 (34.4%) severely ill patients, respectively. The levels of T-SFTSV, F-SFTSV and U-SFTSV were positively correlated with the load of SFTSV in blood. We firstly revealed that SFTSV positive rate of throat swabs were correlated with occurrence of pneumonia and case fatality rate of patients (P < 0.0001). Specific precaution measures were applied by healthcare workers in participating cardiopulmonary resuscitation and orotracheal intubation for severely ill patients with positive T-SFTSV, no event of SFTSV human-to-human transmission occurred after application of effective PPEs. Conclusions. Our research demonstrated SFTSV could shed out from blood, oropharynx, feces and urine in severely ill patients. The excretion of SFTSV from these parts was positively correlated with viral load in the blood. Effective prevention measures against SFTSV human-to-human transmission are needed.