Biomaterial Database

Risk-based serological survey of bluetongue and the first evidence of bluetongue virus serotype 26 circulation in Tunisia. 2022

Kalthoum Sana, and Sghaier Soufien, and Ben Hassine Thameur, and Teodori Liana, and Spedicato Massimo, and Guesmi Kaouther, and Gharbi Raja, and Hajlaoui Haikel, and Bel Haj Mohamed Bassem, and Khalfaoui Wiem, and Lachtar Monia, and Ben Salem Ameni, and Fatnassi Naouel, and Dhaouadi Anissa, and Ben Ali Mehdi, and Thabet Sarah, and Seghaier Chedia, and Savini Giovanni, and Hammami Salah

National Centre of Zoosanitary Vigilance, Ministère de L'agriculture et des Ressources Hydrauliques, Tunis, Tunisia.

Bluetongue (BT), a vector-borne disease of wild and domestic ruminants, is responsible for severe economic losses in flocks. To reduce this impact, a surveillance and control plan was implemented in Tunisia. However, the epidemiological situation of BT remains incompletely understood, especially for the circulating serotypes. The aim of this survey was to determine the seroprevalence, to identify the circulating serotypes and to identify the associated risk factors for bluetongue virus (BTV) circulation in Tunisia using risk-based sampling (RBS). A total of 3314 blood samples were randomly collected from 67 sectors using risk-based sampling and screened by competitive enzyme-linked immunosorbent assays (c-ELISAs). Out of the 1330 positive samples, 200 samples were analysed by serum neutralization test (SNT) to identify circulating BTV serotypes. Of 3314 sera, 1330 were c-ELISA-positive (40.1%) for antibodies against the BTV structural protein VP7. The result of SNT showed the presence of BTV-1, BTV-2, BTV-3, BTV-4 and, for the first time in Tunisia, BTV-26. The logistic regression model revealed that older animals had nearly two times the odds of being infected with BTV compared to younger animals. Flocks with a history of BT were almost 1.5 times more likely to be at risk for contracting BTV infection. The flock size, housing indoors and intensive production system were significant protective factors. High seroprevalence of BTV among sheep was highlighted in Tunisia. The neutralization test showed the presence of the following BTV serotypes: BTV-1, BTV-2, BTV-3, BTV-4 and, for the first time in Tunisia, BTV-26. Age, production system and flock size were important variables associated with BTV infection in sheep. This finding is crucial, as it will allow the adjustment of the BT control programme in Tunisia.

UI	MeSH Term	Description	Entries
D001819	Bluetongue	A reovirus infection, chiefly of sheep, characterized by a swollen blue tongue, catarrhal inflammation of upper respiratory and gastrointestinal tracts, and often by inflammation of sensitive laminae of the feet and coronet.	Blue Tongue,Tongue, Blue
D001820	Bluetongue virus	The type species of ORBIVIRUS causing a serious disease in sheep, especially lambs. It may also infect wild ruminants and other domestic animals.	Ovine Catarrhal Fever Virus,Blue Tongue Virus,Blue Tongue Viruses,Bluetongue Viruses
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000914	Antibodies, Viral	Immunoglobulins produced in response to VIRAL ANTIGENS.	Viral Antibodies
D012756	Sheep	Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.	Ovis,Sheep, Dall,Dall Sheep,Ovis dalli
D012757	Sheep Diseases	Diseases of domestic and mountain sheep of the genus Ovis.	Ovine Diseases,Disease, Ovine,Disease, Sheep,Diseases, Ovine,Diseases, Sheep,Ovine Disease,Sheep Disease
D014416	Tunisia	A country in northern Africa between ALGERIA and LIBYA. Its capital is Tunis.
D016036	Seroepidemiologic Studies	EPIDEMIOLOGIC STUDIES based on the detection through serological testing of characteristic change in the serum level of specific ANTIBODIES. Latent subclinical infections and carrier states can thus be detected in addition to clinically overt cases.	Seroprevalence,Seroepidemiologic Study,Seroepidemiological Study,Studies, Seroepidemiologic,Study, Seroepidemiologic,Seroepidemiological Studies,Seroprevalences,Studies, Seroepidemiological,Study, Seroepidemiological
D065288	Serogroup	A set of variants within a species of microorganisms that are antigenically, closely related. With bacteria, a serogroup refers to a group that shares a common antigen.	Serotype,Serovar,Serogroups,Serotypes,Serovars