Isolation and characterization of genetic variants of Orthohantavirus hantanense from clinical cases of HFRS in Jiangxi Province, China.

Background: Hemorrhagic fever with renal syndrome (HFRS) is a severe public health problem in Jiangxi province, China. Previous studies reported genetic variants of Orthohantavirus hantanense (Hantaan virus, HTNV) in rodents in this area. However, the relationship between HTNV variants and human infection needs to be confirmed. This study aimed to identify the HTNV variants in patients and to understand the clinical characteristics of HFRS caused by these variants. Methods: Samples were collected from hospitalized suspected cases of HFRS during the acute phase. HFRS cases were confirmed using quantitative real-time RT-PCR. Peripheral blood mononuclear cells (PBMC) from patients with HFRS were inoculated into Vero-E6 cells for viral isolation. The genomic sequences of HTNV from patients were obtained by amplicon-based next-generation sequencing. A retrospective analysis was conducted on the clinical characteristics of the patients. Results: HTNV RNA was detected in 53 of 183 suspected HFRS patients. Thirteen HTNVs were isolated from 32 PBMCs of HFRS cases. Whole genome sequences of 14 HTNVs were obtained, including 13 isolates in cell culture from 13 patients, and one from plasma of the fatal case which was not isolated successfully in cell culture. Genetic analysis revealed that the HTNV sequence from the 14 patients showed significant variations in nucleotide and amino acid to the HTNV strains found in other areas. Fever (100%, 53/53), thrombocytopenia (100%, 53/53), increased serum aspartate aminotransferase (100%, 53/53), and increased lactate dehydrogenase (96.2%, 51/53) were the most common characteristics. Severe acute kidney injury was observed in 13.2% (7/53) of cases. Clinical symptoms, such as pain, petechiae, and gastrointestinal or respiratory symptoms were uncommon. Conclusion: The HTNV genetic variants cause human infections in Jiangxi. The clinical symptoms of HFRS caused by the HTNV genetic variant during the acute phase are atypical. In addition to renal dysfunction, attention should be paid to the common liver injuries caused by these genetic variants. Author summary: HTNV causes severe HFRS in Eastern Asia. Previous studies reported genetic variants or new genotypes of HTNV in animals in South Korea and many parts of China. However, little is known about the clinical characteristics of patients infected by the HTNV variant, because it is difficult to isolate HTNV from patients, and few HTNV variants were confirmed from patients. In this study, we use PBMC from patient to coculture with Vero-E6 cells and a 28-day passage isolation protocol for vial isolation, 13 HTNVs were successfully isolated from patients with a recovery rate of over 40%. We also established an amplicon-based next-generation sequencing method for HTNV whole gene sequencing and whole genome sequences of HTNVs from 14 patients were obtained. Genetic analysis revealed that the complete sequences from the patients showed significant variations in nucleotide and amino acid to the HTNVs found in other areas. Viral isolation and whole genome sequencing confirm that the HTNV variant causes human infection in Jiangxi province. The clinical symptoms of HFRS caused by the HTNV genetic variant during the acute phase are atypical, and laboratory diagnoses are needed. These results provide useful guidance for orthohantaviruses isolation from clinical cases and are important for HFRS diagnosis in clinical practice. [ABSTRACT FROM AUTHOR]