Prevalence of rabbit haemorrhagic disease virus 2 in Delta and Upper Egypt

Abstract

Rabbit viral haemorrhagic disease (RVHD) is a fatal threat to rabbits causing long-term problems and significant economic losses. In the current study, RVHD was identified and characterised in naturally infected rabbits in order to assess the genetic diversity of RHDV circulating in different Egyptian provinces from January 2019 to January 2022. Nineteen suspected samples were collected from outbreaks that occurred in nine provinces during 2019–2022. Ten liver samples out of nineteen were positive in the slide and plate haemagglutination (HA) test. HA titres ranged from 5 log2 to 12 log2. RHDV-positive liver homogenates were confirmed with RT-PCR and histopathology. Further characterisation of the selected four viral strains was performed by nucleotide sequencing of VP60 gene. Based on nucleotide sequence analysis, three isolates were identified as RHDV2 strains, while one isolate was assigned as RHDV1 strain.