Bluetongue in China: Current Status of Viruses, Vectors, Detection Methods, and Vaccines

Bluetongue (BT) is a vector-borne viral disease caused by the bluetongue virus (BTV), which can affect a variety of wild and domestic ruminants. Due to its significant impact on ruminant health and national economies, BT is classified as a notifiable multispecies disease by the World Organization for Animal Health (WOAH). In China, BT is listed as a Class II multispecies animal disease. This article provides a comprehensive review of the distribution of BTV and its primary insect vector, Culicoides, in China. Since BTV was first reported in China in 1979, BTV antibody-positive samples have been detected in most parts of the country, with a total of 17 serotypes of BTV isolated (BTV-1, 2, 3, 4, 5, 7, 9, 11, 12, 14, 15, 16, 17, 20, 21, 24, and 29). Culicoides are widely distributed across China. Currently, studies have been conducted on climatic factors influencing their distribution and blood-sucking habits. To improve the efficiency of BTV detection in China, various detection methods have been explored, including polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), bio-bar code assay (BCA) for viral detection, as well as enzyme-linked immunosorbent assay (ELISA), agar gel immunodiffusion (AGID) and colloidal gold immunochromatography test strips for antibody detection. Additionally, inactivated vaccines, attenuated vaccines, and recombinant vaccines were also investigated. This review summarizes the current knowledge on BTV vectors, viruses, and surveillance, as well as the development of BT vaccines in China. In light of the current situation of BT in China, it proposes comprehensive prevention and control recommendations, including enhancing awareness of the hazards of BT, implementing an integrated prevention and control technology system, and strengthening research related to BT prevention and control.