Akabane virus (AKAV) is an insect-borne virus belonging to the genus Orthobunyavirus of the family Peribunyaviridae. It is the etiologic agent of Akabane disease (AD), which emerged in Asia, Australia, and the Middle East causing severe economic losses among domestic and wild animals. AKAV has not received enough attention in Egypt, and its evidence among Egyptian animals has never been reported. Therefore, this study used ELISA assay to investigate the seroprevalence of AKAV among Egyptian dairy and beef cattle in eight localities of Beheira province, north Egypt. Out of 368 investigated plasma samples, the overall AKAV seroprevalence was 54.3% (95% CI: 50.8-61.4). AKAV antibodies were detected in all examined cattle farms (7/7) and the majority of abattoirs (8/9). Age, sex, breed, and location of the tested cattle were analyzed as risk factors for AKAV infection. A higher significant increase in seropositivity was obtained in cattle who were aged >5 years (p < 0.0001; OR = 9.4), females (p < 0.0001, OR = 8.3), or Holstein breed (p < 0.0001, OR = 22.6) than in younger ages, males, and Mixed and Colombian zebu breeds, respectively. Moreover, a significant variation in AKAV seroprevalence between the tested locations was noticed. Ultimately, a multivariable analysis concluded that age (p = 0.002, OR = 3.32, 95% CI = 1.57-7.04) and breed (p = 0.03, OR = 1.69, 95% CI = 1.05-2.72) were significant risks for AKAV infection. In conclusion, this study is the first to detect AKAV infection in Egyptian animals.

Akabane virus, the pathogen-causing Akabane disease, is an arthropod-borne virus (arbovirus) transmitted by the Culicoides biting midge. A nationwide serological surveillance program for bovine arboviral diseases, including Akabane disease, has been established in Japan to monitor the circulation of arboviruses by targeting sentinel calves. Okinawa, which is located in the southwestern-most region of Japan, is a high-risk area for incursion of arboviruses. The aim of the present study was to identify the meteorological factors related to farm-level seroconversion of Akabane virus by analyzing the serological surveillance data for sentinel calves collected in Okinawa between 2007 and 2015. Rainfall in winter, spring, and autumn was positively associated with seroconversion. Adequate rainfall seems to keep the soil in a suitably moist state for growth and survival of biting midges. Maximum temperature in winter was also positively associated with seroconversion in sentinel calves. The warmer temperatures in winter may provide conditions suitable for shortening the larval development cycle and increase production of adult midges. Our findings indicate that meteorological factors such as temperature and rainfall may be important factors that produce circumstances conducive to effective transmission of the virus between vectors and the host. The results of this study provide a better understanding of the circulation of arboviruses and offer suggestions for developing better surveillance and measures to prevent arboviral disease.

Akabane disease, which is distributed in temperate and tropical regions in the world, is a vector-borne disease of ruminants caused by the Akabane virus, transmitted by Culicoides biting midges. In 2011, outbreaks of Akabane viral encephalomyelitis occurred in the Shimane Prefecture in western Japan. In this study, a spatial epidemiological analysis was conducted to understand environmental factors associated with the spread of Akabane disease. By applying a conditional autoregressive model, the relationship between infection and environmental variables was explored. The results showed that the dominance of farmlands and the presence of infected farms within a 3-km radius had a significant effect on infection. This result implies that land use, which would relate with the vector habitat, and the presence of neighboring infected farms as a source of infection may have influenced the spread of the disease in this region. These findings provide basic insights into the spread of Akabane disease and useful suggestions for developing a surveillance program and preventive measures against the disease.