Emergence of Recombinant Myxoma Virus in Algerian Farmed Rabbits: Molecular and Phylogenetic Evidence.

Abstract

Myxomatosis is a severe viral disease of lagomorphs that has recently seen the emergence of a recombinant myxoma virus (MYXV). Data from Africa remain scarce. Here we report the first confirmed detection and genomic characterization of a recombinant MYXV in Algeria. Two domestic rabbits from a backyard smallholding in El Affroun (Blida province) were presented on 19 October 2022 with classical signs of myxomatosis, including marked facial edema, severe mucopurulent blepharoconjunctivitis, and respiratory involvement. Necropsy and histopathology showed lesions typical of myxomatosis (epithelial hyperplasia with ballooning degeneration, intracytoplasmic inclusions, ulceration, stromal expansion by myxoma cells, and vascular hyperemia and leukostasis). MYXV DNA was detected in multiple tissues from both animals, and virus isolation on RK-13 cells produced cytopathic effects (CPEs) by days 5-7 postinoculation. The Algerian MYXV sequence showed >99.9% nucleotide identity to the MYXV Toledo strain (GenBank Accession Number MK836424.1). Phylogenetic analysis placed the Algerian strain within the recombinant ha-MYXV cluster, between earlier Spanish sequences (2018) and more recent Northern European sequences (2024), with the most recent common ancestor estimated around January 2017 (95% HPD July 2015-May 2018). These findings extend the known range of recombinant MYXV beyond Europe and highlight introduction risks at the pet-farm-wildlife interface in North Africa. We recommend strengthened vaccination of pet and farmed rabbits, pragmatic biosecurity in smallholdings, and targeted surveillance of hare populations to clarify sources and transmission routes.