[Source: PLOS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]
OPEN ACCESS / PEER-REVIEWED / RESEARCH ARTICLE
Seroprevalance of antibodies specific for severe fever with thrombocytopenia syndrome virus and the discovery of asymptomatic infections in Henan Province, China
Yanhua Du , Ningning Cheng , Yi Li, Haifeng Wang, Aiguo You, Jia Su, Yifei Nie, Hongxia Ma, Bianli Xu , Xueyong Huang
Published: November 25, 2019 / DOI: https://doi.org/10.1371/journal.pntd.0007242 / This is an uncorrected proof.
Severe fever with thrombocytopenia syndrome (SFTS) is a severe emerging disease caused by SFTS virus (SFTSV), and the geographical distribution of SFTS has been increasing throughout China in recent years. To assess SFTSV-specific antibody seroprevalence, a cross-sectional study was conducted for healthy people in high SFTS endemic areas of Henan province in 2016.
This study used a stratified random sampling method to select 14 natural villages as the investigation sites. From April to May 2016, participants completed a questionnaire survey and serum samples were collected. All serum samples were subjected to ELISA to detect SFTSV-specific IgM and IgG. All IgM-positive samples were further tested by real-time RT-PCR, and isolation of virus from serum was attempted. Any participant who was IgM-positive was followed up with a month later to confirm health status.
In total, 1463 healthy people participated in this study. The average seropositive rates for SFTSV-specific IgG and IgM were 10.46% (153/1463) and 0.82% (12/1463), respectively. IgM was detected in 12 individuals, and SFTSV RNA was detected in six of them. Virus was isolated from five of the six SFTSV RNA-positive individuals, and phylogenetic analyses revealed that all five isolates belonged to SFTSV group A. No IgM-positive participants exhibited any symptoms or other signs of illness at the one-month follow up.
This study identified a relatively high incidence of SFTSV-specific antibody seropositivity in healthy people in Xinyang city. Moreover, our data provide the first evidence for asymptomatic SFTSV infections, which may have significant implications for SFTS outbreak control.
Severe fever with thrombocytopenia syndrome (SFTS) is a severe emerging infectious disease caused by SFTS virus (SFTSV) that was first discovered in rural areas of China. Henan province has had the largest number of SFTS cases in China every year since the disease was discovered, however, seropositivity for SFTSV-specific antibodies in healthy people in this region is still not clear. To address this issue, a cross-sectional survey was performed in high endemic areas from April to May 2016. The results showed that SFTSV seroprevalence was relatively high and possibly increasing. Notably, SFTSV RNA, as well as virus itself, was isolated from specimens obtained from healthy people. This study confirmed there are asymptomatic SFTSV infections in humans, and it is the first to report SFTSV isolation from healthy people.
Citation: Du Y, Cheng N, Li Y, Wang H, You A, Su J, et al. (2019) Seroprevalance of antibodies specific for severe fever with thrombocytopenia syndrome virus and the discovery of asymptomatic infections in Henan Province, China. PLoS Negl Trop Dis 13(11): e0007242. https://doi.org/10.1371/journal.pntd.0007242
Editor: Abdallah M. Samy, Faculty of Science, Ain Shams University (ASU), EGYPT
Received: February 10, 2019; Accepted: October 4, 2019; Published: November 25, 2019
Copyright: © 2019 Du et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the manuscript and its Supporting Information files.
Funding: H.X.Y received grants from the National Natural Science Foundation of China (NO 81573204 https://isisn.nsfc.gov.cn/egrantweb/) and Henan provincial medical science and technology program (grant no.2018010029) .X.B.L. recieved a grant from the National Natural Science Foundation of China (NO 81773500 https://isisn.nsfc.gov.cn/egrantweb/).D.Y.H received a grant from Henan provincial medical science and technology program (grant no.2018020510). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
Keywords: Serology; Seroprevalence; SFTS; Henan; China.