The increasing threat of vector-borne diseases (VBDs) represents a great challenge to those who manage public and animal health. Determining the spatial distribution of arthropod vector species is an essential step in studying the risk of transmission of a vector-borne pathogen (VBP) and in estimating risk levels of VBD. Risk maps allow better targeting surveillance and help in designing control measures. We aimed to study the geographical distribution of Culicoides imicola, the main competent vector of Bluetongue virus (BTV) in sheep in Tunisia. Fifty-three records covering the whole distribution range of C.imicola in Tunisia were obtained during a 2-year field entomological survey (August 2017 - January 2018 and August 2018 - January 2019). The ecological niche of C. imicola is described using ecological-niche factor analysis (ENFA) and Mahalanobis distances factor analysis (MADIFA). An environmental suitability map (ESM) was developed by MaxEnt software to map the optimal habitat under the current climate background. The MaxEnt model was highly accurate with a statistically significant area under curve (AUC) value of 0.941. The location of the potential distribution of C. imicola is predicted in specified regions of Tunisia. Our findings can be applied in various ways such as surveillance and control program of BTV in Tunisia.

Bluetongue (BT) is an arthropod-borne viral disease of domestic and wild ruminants caused by Bluetongue virus (BTV). It has been reported in most tropical and subtropical regions of the world which raises significant socioeconomic concerns for international trade in animals and animal products. However, recent and updated information related to the current prevalence of BT in Malaysia is limited. The last holistic report was reported during BT outbreaks in the year of 1990s. This study aims to determine the current status of seroprevalence of BT among ruminants in Malaysia from 2013 to 2019. A total of 9,787 serum samples from buffalo, cattle, deer, goat as well as sheep were received from January 2013 until December 2019. All these serum samples were subjected to Agar Gel Immunodiffusion (AGID) test to detect the presence of antibodies towards BTV. The overall status of BTV was 20.18 % (1,975/9,787), with 56 % (14/25) in deer, 46.4 % (428/922) in cattle and 35.7 % (60/168) in buffalo. Positive BT antibodies were detected in young animals (<6 months) with 30.60 %, while 23.61 % in adult animals (>2 years). The results of this study revealed that BTV is still circulating at low level in domestic and wild ruminant livestock animals in Malaysia. It is suggested that this disease needs close monitoring to prevent possible outbreaks in the future.