School of Public Health (Shenzhen), Sun Yat-sen University, Shenzhen, China; Shenzhen Key Laboratory of Pathogen and Immunity, State Key Discipline of Infectious Disease, Shenzhen Third People's Hospital, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen 518112, China.
Shenzhen Key Laboratory of Pathogen and Immunity, State Key Discipline of Infectious Disease, Shenzhen Third People's Hospital, Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen 518112, China.
Int J Infect Dis. 2019 Nov;88:80-87. doi: 10.1016/j.ijid.2019.09.002. Epub 2019 Sep 6.
Eight additional provinces in western China reported human infections for the first time during the fifth wave of human H7N9 infections. The aim of this study was to analyze the epidemiological and virological characteristics of this outbreak.
The epidemiological data of H7N9 cases from the newly affected western Chinese provinces were collected and analyzed. Full-length genome sequences of H7N9 virus were downloaded from the GenBank and GISAID databases, and phylogenetic, genotyping, and genetic analyses were conducted.
The peak of human infections in the newly affected western Chinese provinces was delayed by 4 months compared to the eastern Chinese provinces, and both low pathogenic (LP) and highly pathogenic (HP) H7N9-infected cases were found. The LP- and HP-H7N9 virus belonged to 10 different genotypes (including four new genotypes), of which G11 and G3 were the dominant genotypes, respectively. Almost all of these viruses originated from eastern and southern China and were most probably imported from neighboring provinces. Genetic characteristics of the circulating viruses were similar to those of the viruses from previously affected provinces during Wave Five.
A delayed peak of human infections was observed in the newly affected western Chinese provinces, and reassortment has been ongoing since the introduction of H7N9 viruses. This study highlights the importance of continued surveillance of the circulation and evolution of H7N9 virus in western China.
中国西部的另外 8 个省份在第五波人感染 H7N9 疫情中首次报告了人间感染病例。本研究旨在分析此次疫情的流行病学和病毒学特征。
收集并分析新受影响的中国西部省份人感染 H7N9 病例的流行病学数据。从 GenBank 和 GISAID 数据库下载 H7N9 病毒的全长基因组序列，并进行系统进化、基因分型和遗传分析。
与中国东部省份相比，新受影响的中国西部省份的人间感染高峰推迟了 4 个月，并且发现了低致病性（LP）和高致病性（HP）H7N9 感染病例。LP-H7N9 和 HP-H7N9 病毒属于 10 种不同的基因型（包括 4 种新基因型），其中 G11 和 G3 分别为主要基因型。这些病毒几乎均来源于中国东部和南部地区，很可能是从邻近省份输入的。流行的病毒的遗传特征与第五波疫情中已受影响省份的病毒相似。
新受影响的中国西部省份的人间感染高峰出现延迟，自 H7N9 病毒引入以来，持续发生重配。本研究强调了持续监测中国西部 H7N9 病毒传播和进化的重要性。
