Serosurvey of Bluetongue virus in small ruminants in Egypt and its associated risk factors.

Bluetongue is an emerging, non-contagious, vector-borne disease that affects both domestic and wild ruminants. This study aimed to determine the seroprevalence of Bluetongue virus (BTV) in four Egyptian governorates and to evaluate the associated risk factors. A total of 740 serum samples were collected from 380 sheep and 360 goats and tested using a commercial competitive ELISA (cELISA). The overall BTV seroprevalence was 16.2%, with 17.1% in sheep and 15.3% in goats. Although the seroprevalence did not differ significantly across the studied regions, the highest prevalence was recorded in Kafr El-Sheikh (20.7%). Univariable analysis revealed a significant association between BTV seropositivity and several factors, including sex, age, presence of vectors, history of abortion, and contact with cattle. According to the multivariable logistic regression model, females, animals older than 2 years, and those with a history of abortion were respectively 2.3, 2.6, and 1.6 times more likely to be seropositive. Furthermore, the presence of insect vectors and close contact with cattle increased the risk of BTV infection by 1.6 and 2.1 times, respectively. This study highlights the significant risk factors associated with BTV seropositivity, with a slightly higher prevalence observed in sheep compared to goats. These findings underscore the need for effective disease surveillance, management, and control strategies targeting both sheep and goat populations.