Occurrence of bovine ephemeral fever in Okinawa Prefecture, Japan, in 2012 and development of a reverse-transcription polymerase chain reaction assay to detect bovine ephemeral fever virus gene

Abstract

In September 2012, several cows and a calf showed decreased activity, anorexia and fever on Ishigaki Island, Okinawa Prefecture, Japan, and the cases were diagnosed as bovine ephemeral fever (BEF). We isolated BEF virus (BEFV) from one of the affected cows and then determined the complete genome sequence of the G gene, which encodes a class I transmembrane glycoprotein of BEFV. The BEFV isolate in this case, ON-3/E/12, was sorted into the same cluster as other BEFV isolates in Japan, Taiwan and China obtained in 1996−2004 and was most closely related to a 2002 Chinese isolate, JT02L, according to the phylogenetic analysis of the complete G gene. Since inactivated vaccines for BEF available in Japan are considered effective against the ON-3/E/12 isolate as well as other isolates in East Asia from 1996−2004, annual vaccination should be conducted to prevent BEF in Okinawa. Additionally, in this study, we developed an RT-PCR assay to detect the BEFV gene in Japan and neighboring countries. Our assay was able to amplify target sequences in all of the tested BEFV isolates, including 18 isolates in Japan and another isolate in Australia. The assay was found to be useful also for testing RNA samples extracted from bovine peripheral blood mononuclear cells, and the detection limit of the assay was 10 copies per tube. We believe that our assay would be an important tool for the screening of BEFV infection and the diagnosis of BEF.

Development of a recombinase polymerase amplification combined with lateral-flow dipstick assay for detection of bovine ephemeral fever virus

“…Molecular and Cellular Probes 38 (2018) [31][32][33][34][35][36][37] was also carried out by reverse transcription PCR (RT-PCR) assay with gel electrophoresis detection previously published by Niwa et al [24]. Two methods were operated with the same amount of template.…”

“…Cell culture and indirect immunofluorescent detection have long been used for the detection of BEFV [17,[20][21][22]. In addition, BEFV can be routinely detected by the conventional RT-PCR, real-time quantative (q) PCR, and enzyme-linked immunosorbent assay (ELISA) as well as the virus neutralization test [23][24][25][26]. However, those common detection methods are laboratory-based and require sophisticated instruments operated by special trained personnel.…”

Bovine ephemeral fever epidemics in Kingdom Saudi Arabia: clinical, epidemiological and molecular investigation

“…Our RT-PCR results support others [28] in the belief that RT-PCR is a superior test for the provision of rapid and specific data for BEFV detection. The conventional RT-PCR is sensitive, specific and rapid test for detection of BEFV in clinical samples [29], moreover we found the RT-PCR assay to be useful for testing RNA samples extracted from peripheral blood mononuclear cells and so it could be an important tool for the screening of BEF infection [30].…”

Resurgence of bovine ephemeral fever in mainland Japan in 2015 after a 23-year absence

“…The East Asian lineage was further separated into three major clades in chronological order [13, 19]. The Japanese 2015 BEFVs were phylogenetically distinct from the previous Japanese isolates, but were included in the newest clade with BEFVs identified in Taiwan in 2013–2014, mainland China in 2011–2012 and Turkey in 2012.…”