ABSTRACT
Since the first detection of rabbit hemorrhagic disease (RHD), the rabbit hemorrhagic disease virus (RHDV) has been responsible for high morbidity and mortality worldwide, both in domestic and in wild rabbits. Despite the apparent control of RHD in rabbitries through vaccination, several studies highlighted the rapid evolution of RHDV by recombination, which may facilitate the emergence of new pathogenic strains. The aim of this study was to confirm the presence and characterize RHDV in Algeria. For this, rabbit samples were collected in the north of Algeria, between 2018 and 2021, from small farms where the virus was suspected after the sudden death of a high number of rabbits, and from healthy hunted wild rabbits. The domestic rabbits revealed clinical signs and lesions that were suggestive of RHD. RT-PCR showed that 79.31% of the domestic rabbit samples were positive for RHDV, while in 20.69%, including the hunted rabbits, the virus was not detected. Phylogenetic analysis of the Algerian strains allowed the confirmation and identification as GI.2 (RHDV2), and showed a close relation to GI.3P-GI.2 recombinant strains, suggesting a potential introduction from other countries, with an older strain potentially originated from neighboring Tunisia, while more recent isolates grouped with strains from North America. Our study reports for the first time the presence of GI.2 (RHDV2) in Algeria with multiple routes of introduction. Consequently, we propose that RHDV control in Algeria should be based on epidemiological surveys in association with an adequate prophylactic program.
ABSTRACT
AIM: The aim of the present study was to determine the prevalence and intensity of rabbit coccidiosis (Oryctolagus cuniculus) in North Algeria. MATERIALS AND METHODS: During the study, 40 rabbit farms were investigated. The farms are located in the provinces of Tizi Ouzou, Médéa, and Djelfa which distributed, respectively, into three regions: East Tell Atlas Mountains, Central Tell Atlas Mountains, and High Plateaus. The number of oocyst per gram of feces (OPG) was determined by McMaster technique, and the Eimeria species were identified using morphological criteria. RESULTS: In the farms investigated, the prevalence of coccidian infection was estimated to 90% (80.7-99.3%) in rabbits after weaning. The classification of the farms according to their parasite load allowed us to show that 37.5% of the prospective farms have an oocyst excretion between 104 and 5×104 oocysts per gram and 22.5% excrete >5×104 oocysts per gram. Excretion levels by region show that the region of East Tel Atlas Mountains ranks first with 79% of farms with a parasitic load >104 coccidians compared to the regions of Central Tel Atlas Mountains and High Plateaus. In total, eight species of Eimeria were identified from oocyst-positive samples. Mixed infections with four Eimeria species were common. E. magna is the dominant species in comparison with E. media and E. irresidua with respective frequencies of 42.5% and 17.6% and 14.9% (p<0.001). Our results showed that the farms using anticoccidial drugs for their rabbits were low (25%) and the percentage of farms with poor hygienic conditions was 65%. There was a significant association between increased oocysts excretion and control measures of coccidian infection. CONCLUSION: The study revealed an overall prevalence of 90% in the three Algerian regions. A strong association was observed between Eimeria infection and hygienic status and preventional chemotherapy.
