Putative Novel Atypical BTV Serotype ‘36’ Identified in Small Ruminants in Switzerland

Abstract

We identified a putative novel atypical BTV serotype ‘36’ in Swiss goat flocks. In the initial flock clinical signs consisting of multifocal purulent dermatitis, facial oedema and fever were observed. Following BTV detection by RT-qPCR, serotyping identified BTV-25 and also a putative novel BTV serotype in several of the affected goats. We successfully propagated the so-called “BTV-36-CH2019” strain in cell culture, developed a specific RT-qPCR targeting Segment 2, and generated the full genome by high-throughput sequencing. Furthermore, we experimentally infected goats with BTV-36-CH2019. Regularly, EDTA blood, serum and diverse swab samples were collected. Throughout the experiment, neither fever nor clinical disease was observed in any of the inoculated goats. Four goats developed BTV viremia, whereas one inoculated goat and the two contact animals remained negative. No viral RNA was detected in the swab samples collected from nose, mouth, eye, and rectum, and thus the experimental infection of goats using this novel BTV serotype delivered no indications for any clinical symptoms or vector-free virus transmission pathways. The subclinical infection of the four goats is in accordance with the reports for other atypical BTVs. However, the clinical signs of the initial goat flock did most likely not result from infection with the novel BTV-36-CH0219.

Bluetongue and Epizootic Hemorrhagic Disease in the United States of America at the Wildlife–Livestock Interface

“…Epidemiological differences between these two related, but different viruses, are due to the geographic distribution of the virus serotypes and differences in the distribution of ruminant hosts and Culicoides spp. Worldwide, there are currently seven EHDV serotypes (EHDV-1,2, and 4 to 8) and 27 BTV serotypes (BTV-1 to 27) [ 32 , 33 , 34 ], although the number of BTV serotypes may increase as putative new BTV serotypes and strains have been described (e.g., BTV-36-CH2019 and a vaccine-derived putative BTV-28 strain) [ 35 , 36 ]. While vector/host interactions are impacted by climate and habitat suitability, our understanding of the proportion of wild ruminants affected by BTV or EHDV in the USA is also limited to mostly syndromic based reporting of hemorrhagic disease rather than virus isolation in a targeted population [ 37 ].…”

Identification of the Genome Segments of Bluetongue Virus Type 26/Type 1 Reassortants Influencing Horizontal Transmission in a Mouse Model

“…To date, more than 36 distinct serotypes of BTV have been isolated from ruminants including sheep, cattle and goats [3]. The BTV genome is composed of ten segments of double stranded RNA.…”

“…BTV serotype is determined by the virus outer capsid and cell attachment protein VP2 (encoded by genome segment 2), which elicits neutralising antibodies in infected vertebrate hosts [4][5][6]. Since 2008, several atypical BTV serotypes have been isolated (primarily from small ruminants, including goats or sheep) that do not replicate either in KC cells, or in adult C. sonorensis [3,[6][7][8][9]. These viruses are believed to be transmitted by direct contact, from individual infected to uninfected ruminant hosts [10].…”

Inhibition of Orbivirus Replication by Fluvastatin and Identification of the Key Elements of the Mevalonate Pathway Involved

“…Several orbiviruses can also infect humans, including members of the Changuinola virus , Corriparta virus , Lebombo virus , Orungo virus and Great Island virus species [ 2 ]. Orbiviruses are emerging pathogens throughout the globe, as demonstrated by recent disease outbreaks in Europe, the detection of ‘novel’ BTV serotypes [ 3 , 4 ] and the emergence of novel orbiviruses such as Peruvian horsesickness virus in Australia and Peru [ 5 ].…”