Dual Infection with Bluetongue Virus Serotypes and First-Time Isolation of Serotype 5 in India

Abstract

Summary Bluetongue is endemic in India and has been reported from most Indian states. Of late, the clinical disease is most frequently seen in the states of Andhra Pradesh, Telangana (erstwhile Andhra Pradesh state), Tamil Nadu and Karnataka. Our analysis of diagnostic samples from bluetongue outbreaks during 2010–2011 from the state of Karnataka identified bluetongue virus (BTV) serotype 5 (BTV‐5) for the first time in India. One of the diagnostic samples (CH1) and subsequent virus isolate (IND2010/02) contained both BTV‐2 and BTV‐5. Segment 2 (seg‐2) sequence data (400 bp: nucleotides 2538–2921) for IND2010/02‐BTV5, showed 94.3% nucleotide identity to BTV‐5 from South Africa (Accession no. AJ585126), confirming the virus serotype and also indicating that Seg‐2 was derived from a Western topotype, which is in contrast to serotype 2, that belongs to an Eastern topotype. BTV‐5 has been recently reported from Africa, China, French islands and the Americas. Although the exact source of the Indian BTV‐5 isolate is still to be confirmed, recent identification of additional exotic serotypes in India is of real concern and might add to the severity of the disease seen in these outbreaks.

Identification and genomic characterization of the first isolate of bluetongue virus serotype 5 detected in Australia

“…) and India (Hemadri et al . ) and the close genetic relationship of these isolates with BTV‐5 AUS, suggested a possible Eastern Asia origin for this virus. This route of entry into Australia was corroborated by the identification of BTV‐5 AUS Seg‐3 as a Malaysia A genotype (Pritchard et al .…”

“…There are relatively few documented accounts of BTV-5 isolations worldwide (Table S2) and only one account linking this serotype to a limited disease outbreak in Israel (Brenner et al 2010). The very recent first isolation of BTV-5 in China (Yang et al 2017) and India (Hemadri et al 2017) and the close genetic relationship of these isolates with BTV-5 AUS, suggested a possible Eastern Asia origin for this virus. This route of entry into Australia was corroborated by the identification of BTV-5 AUS Seg-3 as a Malaysia A genotype ).…”

An updated review on bluetongue virus: epidemiology, pathobiology, and advances in diagnosis and control with special reference to India

“… 2016 ; Hemadri et al. 2017 ). In several states of India, BTV antibodies were detected in goat, cattle, camel, buffalo and mithun; however, clinical disease was not frequently reported in these species (Joardar et al.…”

Simultaneous Detection of Bluetongue Virus Serotypes Using xMAP Technology

“…Typically, serotype-specific RT-qPCR is performed to determine the dominant serotype (to infer clinical significance) rather than screen samples for all possible serotypes. Although infections with multiple serotypes have been identified in field samples [ 39 , 40 , 41 ], these may be underreported when using singleplex RT-qPCR detection strategies where samples may only be tested for a limited number of serotypes. Infection of ruminants with multiple BTV serotypes can lead to the emergence of novel, possibly more virulent, BTV strains [ 42 ].…”