Serological evidence of bovine ephemeral fever in Jordan

Abstract

Bovine ephemeral fever (BEF) is an economically significant vector-borne viral disease of cattle and buffaloes caused by an Ephemerovirus in the family Rhabdoviridae. The disease causes production losses and trade restrictions. Although BEF has been reported in several neighboring countries, it had not previously been documented in Jordan. This study describes two suspected BEF outbreaks in Jordan in 2018 and 2021, focusing on clinical and laboratory findings. In 2018, 14 cattle farms in the Jordan Valley were investigated, and 315 animals were examined. Affected cattle exhibited sudden fever, reduced feed intake, and spontaneous recovery within 2–4 days. The morbidity rate was 8.6%, and no deaths were recorded. A total of 122 paired blood and serum samples were collected from clinical, non-clinical, and neighboring animals. Qualitative BEF antibody ELISA testing detected antibodies in three clinical cases, whereas all non-clinical animals were negative. In contrast, during the 2021 investigation, four farms were examined, and 90 cattle showed similar clinical signs. However, BEF antibody testing of 20 serum samples collected from the investigated cattle was negative, and no morbidity or mortality was recorded. Viral RNA was not detected by RT-PCR in both years. These findings confirm the clinical and serological occurrence of BEF in Jordan in 2018, whereas the 2021 event showed no serological or molecular evidence of infection. Continued surveillance and laboratory monitoring are essential for detecting and controlling BEF in the region.