Prevalence of severe fever with thrombocytopenia syndrome virus in ticks and molecular phylogenetic study of viruses in an epidemic area of Suizhou, Hubei Province
- Author:
DAI Ying
;
LIU Cong
;
ZHUANG Hang
;
YUE Miaomiao
;
ZHANG Yating
;
HU Bing
- Publication Type:Journal Article
- Keywords:
Fever with thrombocytopenia syndrome;
severe fever with thrombocytopenia syndrome virus;
tick;
virus carrying rate;
phylogenetic analysis;
Hubei Province
- From:
China Tropical Medicine
2024;24(4):426-
- CountryChina
- Language:Chinese
-
Abstract:
Abstract: Objective To study severe fever with thrombocytopenia syndrome virus (SFTSV) in tick samples from different species and genera in Suizhou City, Hubei Province, China, and to explore the phylogenetic relationship between ticks and patients sources of viruses at the molecular evolutionary level. Methods In 2016 and 2017, over a continuous two-year period, 1 158 ticks were collected from Suizhou, Hubei, and their species and genera were identified. Meanwhile, 86 serum samples were collected to detect SFTSV RNA by real-time quantitative reverse transcription-PCR. All viral RNA-positive supernatants of tick homogenates were inoculated into Vero cells for viral isolation, and full genome sequencing of isolated strains was conducted. Phylogenetic tree research on SFTSV strains from ticks and cases was performed using the bootstrapped maximum-likelihood (1 000 iterations) method with Molecular Evolutionary Genetics Analysis (MEGA) software, ver. 11.0 to provide confidence estimates. Results Haemaphysalis longicornis, Ixodes sinensis, and Rhipicephalus microplus were the dominant species (95.34%) in Suizhou City, Hubei Province, China. Tick samples were pooled according to their species and developmental stage, yielding 832 pools, of which 4 were positive for SFTSV by qRT-PCR. The overall minimum infection rate (MIR) in the region was 0.35%. One SFTSV strain named HB 2016-P35, was successfully isolated from Haemaphysalis longicornis and demonstrated high homology to 16 previously reported patient-derived viruses in Hubei Province, especially to the human strain HB 2017-49 from the same region, with a genome similarity of 99.9%. In addition, the molecular phylogenetic analysis revealed five distinct SFTSV genotypes in Hubei, covering almost all currently known SFTSV genotypes. Conclusions Some areas of Suizhou City, Hubei Province, demonstrate a relatively low level of SFTSV carrying and transmission by ticks. The new SFTSV strain isolated from ticks exhibits similar genotype characteristics and high sequence homology with viruses carried by cases in surrounding cases. The study suggests that tick-to-human transmission is most likely the pathway for human infection with SFTSV, highlighting the need for continual and long-term monitoring of tick carriage of SFTSV in endemic areas.
- Full text:202506161652428754812.Prevalence of severe fever with thrombocytopenia syndrome virus in ticks and molecular phylogenetic study of viruses in an epidemic area of Suizhou, Hubei Province.pdf
