RAPID COMMUNICATION A novel Bluetongue virus serotype 3 strain in Tunisia, November 2016 S. Sghaier 1† | A. Lorusso 2† | O. Portanti 2 | M. Marcacci 2 | M. Orsini 2 | M. E. Barbria 3 | A. S. Mahmoud 2-4 | S. Hammami 5 | A. Petrini 2 | G. Savini 2 1 Institut de la Recherche V et erinaire de Tunisie, Laboratoire de virologie, Univ ersit e de Tunis El Manar, Tunis, Tunisia 2 OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise (IZSAM), Teramo, Italy 3 CRDA-Commissariats R egionaux au D eveloppement Agricole, Menzel Bouzelfa, Tunisia 4 Dipartimento di Scienze Veterinarie, Universit a degli Studi di Pisa, Pisa, Italy 5 Ecole Nationale de M edecine V et erinaire de Sidi Thabet, Tunis, Tunisia Correspondence A. Lorusso, OIE Reference Laboratory for Bluetongue, Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise (IZSAM), Teramo, Italy. Email: a.lorusso@izs.it Funding information Italian Ministry of Health Summary Since 1998, southern Europe has experienced multiple incursions of different sero- types and topotypes of Bluetongue virus, a vector-borne transmitted virus, the cau- sative agent of Bluetongue (BT), a major disease of ruminants. Some of these incursions originated from northern Africa, likely because of wind-blown dissemina- tion of infected midges. In this report, we describe the detection and whole genome characterization of a novel BTV-3 strain identified in a symptomatic sheep in Tuni- sia. Sequences were immediately deposited with the GenBank Database under Accession Nos KY432369-KY432378. Alert and preparedness are requested to face the next vector seasons in northern Africa and the potential incursion of this novel strain in southern Europe. KEYWORDS Bluetongue serotype 3, whole genome sequencing, Tunisia 1 | INTRODUCTION Bluetongue virus (BTV), the type species of the genus Orbivirus within the family Reoviridae, is the causative agent of Bluetongue (BT), one of the OIE-listed major diseases of ruminants. Bluetongue virus is an arbovirus that generally spreads between mammalian hosts by competent species of biting midges (Culicoides spp.). The BTV genome consists of ten segments (Seg-1–Seg-10) of linear dsRNA and it codes for structural (VP1-VP7) and non-structural (NS1-NS5) proteins. VP2 and VP5 (encoded by Seg-2 and Seg-6, respectively) are the most variable BTV proteins (Schwartz-Cornil et al., 2008). They form the outer capsid, representing a target for neutralizing antibodies (particularly VP2), and determine virus sero- type. This virus exists into multiple serotypes (potentially 28, Sun et al., 2016) and two major geographic groups of BTVs have been identified and designated as eastern (e) or western (w) topotype. They include viruses from Australia and the Middle/Far East, or Africa and the Americas, respectively (Maan et al., 2008). Moreover, the Seg-2 and Seg-6 sequences of reference strains of the different BTV serotypes are classified so far as a number of distinct evolution- ary lineages (nucleotypes). As for Seg-2, 12 nucleotypes (A–L) have been so far defined and they also may reflect the serological rela- tionships. As for Seg-6, 11 putative nucleotypes (A–K) are potentially designated but its sequence variation does not show an absolute correlation with serotype (Maan et al., 2015; Schulz et al., 2016; Sun et al., 2016). Importantly, a characteristic of BTV is the ability to “re- assort” genomic segments with related members of the same species (Lorusso, Costessi et al., 2013; Lorusso, Sghaier et al., 2013; Nomi- kou et al., 2015). BTV strains derived from modified live-attenuated vaccines (MLVs) have also been used for BT prevention and isolated in the field (Batten, Maan, Shaw, Maan, & Mertens, 2008; Ferrari et al., 2005; Savini et al., 2014). Although still used in northern † These authors equally contributed to this manuscript Received: 13 January 2017 DOI: 10.1111/tbed.12640 Transbound Emerg Dis. 2017;1–7. wileyonlinelibrary.com/journal/tbed © 2017 Blackwell Verlag GmbH | 1