Eun-Sil Park1, Osamu Fujita1, Masanobu Kimura1, Akitoyo Hotta1, Koichi Imaoka1, Masayuki Shimojima2, Masayuki Saijo2, Ken Maeda1,3, Shigeru Morikawa1,4. 1. Department of Veterinary Science, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan. 2. Department of Virology I, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan. 3. Laboratory of Veterinary Microbiology, Yamaguchi University, Yamaguchi, Japan. 4. Department of Microbiology, Faculty of Veterinary Medicine, Okayama University of Science, Imabari, Ehime, Japan.
Abstract
BACKGROUND: Severe fever with thrombocytopenia syndrome virus (SFTSV) causes severe hemorrhagic fever in humans and cats. Clinical symptoms of SFTS-infected cats resemble those of SFTS patients, whereas SFTS-contracted cats have high levels of viral RNA loads in the serum and body fluids. Due to the risk of direct infection from SFTS-infected cats to human, it is important to diagnose SFTS-suspected animals. In this study, a reverse transcription polymerase chain reaction (RT-PCR) was newly developed to diagnose SFTS-suspected animals without non-specific reactions. METHODOLOGY/PRINCIPLE FINDINGS: Four primer sets were newly designed from consensus sequences constructed from 108 strains of SFTSV. A RT-PCR with these four primer sets successfully and specifically detected four clades of SFTSV. Their limits of detection are 1-10 copies/reaction. Using this RT-PCR, 5 cat cases among 56 SFTS-suspected animal cases were diagnosed as SFTS. From these cats, IgM or IgG against SFTSV were detected by enzyme-linked immunosorbent assay (ELISA), but not neutralizing antibodies by plaque reduction neutralization titer (PRNT) test. This phenomenon is similar to those of fatal SFTS patients. CONCLUSION/SIGNIFICANCE: This newly developed RT-PCR could detect SFTSV RNA of several clades and from SFTS-suspected animals. In addition to ELISA and PRNT test, the useful laboratory diagnosis systems of SFTS-suspected animals has been made in this study.
BACKGROUND:Severe fever with thrombocytopenia syndrome virus (SFTSV) causes severe hemorrhagic fever in humans and cats. Clinical symptoms of SFTS-infectedcats resemble those of SFTS patients, whereas SFTS-contracted cats have high levels of viral RNA loads in the serum and body fluids. Due to the risk of direct infection from SFTS-infectedcats to human, it is important to diagnose SFTS-suspected animals. In this study, a reverse transcription polymerase chain reaction (RT-PCR) was newly developed to diagnose SFTS-suspected animals without non-specific reactions. METHODOLOGY/PRINCIPLE FINDINGS: Four primer sets were newly designed from consensus sequences constructed from 108 strains of SFTSV. A RT-PCR with these four primer sets successfully and specifically detected four clades of SFTSV. Their limits of detection are 1-10 copies/reaction. Using this RT-PCR, 5 cat cases among 56 SFTS-suspected animal cases were diagnosed as SFTS. From these cats, IgM or IgG against SFTSV were detected by enzyme-linked immunosorbent assay (ELISA), but not neutralizing antibodies by plaque reduction neutralization titer (PRNT) test. This phenomenon is similar to those of fatal SFTS patients. CONCLUSION/SIGNIFICANCE: This newly developed RT-PCR could detect SFTSV RNA of several clades and from SFTS-suspected animals. In addition to ELISA and PRNT test, the useful laboratory diagnosis systems of SFTS-suspected animals has been made in this study.
Authors: Xuan Chuong Tran; Yeojun Yun; Le Van An; So-Hee Kim; Nguyen T Phuong Thao; Phan Kim C Man; Jeong Rae Yoo; Sang Taek Heo; Nam-Hyuk Cho; Keun Hwa Lee Journal: Emerg Infect Dis Date: 2019-05 Impact factor: 6.883