Epidemiological and genetic investigation of a cluster of cases of severe fever with thrombocytopenia syndrome bunyavirus

Lingling Mao,Jie Zhang,Yuhong Liang,Lei Yu,Zijiang Wang,Baocheng Deng,Wei Wu,Wenqing Yao,Yun Liu

doi:10.1186/s12879-020-05072-w

Abstract

BackgroundTo analyze and discuss the transmission route of a cluster of cases of severe fever with thrombocytopenia syndrome bunyavirus (SFTSV).MethodWe performed an epidemiological investigation and a genetic analysis of patients with severe fever with thrombocytopenia syndrome (SFTS) caused by SFTSV, their close contacts and the surrounding population.ResultsWe found that all patients had contact with the blood of the first patient. The comparison of gene sequences in the three isolated SFTSV strains showed that the strains were closely related. Six close contacts and nine individuals in the surrounding population were positive for SFTSV IgM antibody.ConclusionWe suspect that the cluster outbreak was transmitted via blood and that the natural reservoir host of SFTSV exists in the patients’ environment.

Highlights

To analyze and discuss the transmission route of a cluster of cases of severe fever with thrombocytopenia syndrome bunyavirus (SFTSV)
The results indicate that they were infected with SFTSV when they contacted the blood of the index patient
Based on the time when the secondary patients contacted the blood of the index patient and the onset time, we estimate that the incubation period for the human-to-human transmission of SFTSV is 7 ~ 11 days, which is similar to the result reported by Xu Zhuping [15]

Summary

Introduction

To analyze and discuss the transmission route of a cluster of cases of severe fever with thrombocytopenia syndrome bunyavirus (SFTSV). Method: We performed an epidemiological investigation and a genetic analysis of patients with severe fever with thrombocytopenia syndrome (SFTS) caused by SFTSV, their close contacts and the surrounding population. Six close contacts and nine individuals in the surrounding population were positive for SFTSV IgM antibody. Severe fever with thrombocytopenia syndrome (SFTS) is a disease clinically characterized by fever, leukopenia, thrombocytopenia and multiple organ damage. It was first reported in the central and eastern regions of China in 2009, and the earliest cases can be traced back to 1996 [1, 2]. The S segment contains 1744 nucleotides, the M segment contains 3378 nucleotides, and the L segment contains 6368 nucleotides [3]

Methods

Results

Discussion

Conclusion