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Abstract Background This paper reports the first pathological and molecular characterization of the novel variant of infectious bronchitis virus (IBV) D181 in poultry flocks in Morocco and Africa. Methods The study includes six poultry farms, involving three flocks of layers aged between 28 and 67 weeks and three broiler flocks aged 27, 39 and 42 days from different regions of Morocco. In all affected layer flocks, a severe drop in egg production with poor eggshell quality was reported. Necropsy of dead birds was carried out, and samples of trachea, lungs, oviduct, ovaries, and kidneys were fixed in 10% neutral buffered formalin for histopathologic examinations, while other portions were stored at -20 °C for molecular analysis. Real time RT-qPCR for IBV gene group was performed, and IBV variants were identified. Partial S1 gene sequences were amplified by conventional RT-PCR, sequenced, and aligned for phylogenetic and amino acid similarity analysis. Results Necropsy of dead birds revealed misshapen and hemorrhagic ovarian follicles with an edematous oviduct and severe reaction in the cecal tonsils. A caseous material accumulation in the sinus was noted in few birds. In contrast, the broiler flocks exhibited respiratory clinical signs such as difficulty in breathing, sneezing, tracheal rales, watery eyes and lethargy, associated with a decrease in feed consumption. Mortality in broiler ranged from 2 to 15%. Histopathological analysis of samples showed a lympho-plasmocytic inflammation in the oviduct, trachea, and lungs. Individual necrosis of epithelial cells, with sloughing of the bronchial epithelium and accumulation of desquamated cells with mucus in the airways, was observed in some birds. Partial S1 gene sequencing and phylogenetic analyses showed that the Moroccan strains were very closely related to D181 strains isolated in Dutch layers and breeders in 2018. Nucleotide sequence identities reached 90.9–95% with the Dutch isolates (strain CK/NL/D181/2018). Conclusion Our sequencing results demonstrate for the first time that the D181 IBV genotype is circulating in Moroccan poultry. These findings justify permanent monitoring of circulating strains in order to appropriately adjust vaccination strategies to align with the evolving field situation.

Avian metapneumovirus (aMPV) is a highly contagious pathogen for broilers. Its epidemiological aspects remain poorly understood in Morocco. Given that, we carried out a pilot seroepidemiological survey from December 2020 to June 2021 to define aMPV seroprevalence in Moroccan broiler flocks in different bioclimatic zones (humid to sub-humid, semi-arid, arid) during winter and spring. According to these zones, 48 flocks not vaccinated against aMPV were selected using a stratified random sampling model. With a simple random sampling strategy, fifteen to thirty sera per flock were collected then analysed using a commercial indirect ELISA kit (CIVTEST AVI TRT®, HIPRA S.A., Amer, Spain) that was able to titre antibodies against aMPV subtypes A and B. Furthermore, questionnaires were shared with veterinarians in charge of flocks to collect data and analyse it with multivariable logistic regression models to identify risk factors associated with virus circulation. From 1142 sera, 912 tested positive with the ELISA used, showing an overall aMPV seroprevalence of 79.86% in the broilers. The arid zone had the highest seroprevalences: 94.16% during winter and 84.82% during spring. Bioclimate and season seemed to contribute to aMPV seropositivity. Likewise, high stocking densities and poor hygiene scores on farms were proven to predispose birds to seropositivity. Hereby, we show the circulation of aMPV in Moroccan broiler farms is influenced by bioclimate, season, density, and hygiene conditions. The present study is the first serological evidence of aMPV in broilers in the Maghreb region.

Describes the first known cases of avian infectious laryngotracheitis (ILT) and avian influenza in Morocco. Routine diagnostic work of the Institut Agronimique et Veterinaire Hasan II in April 28, 2003; Post-mortem examinations of birds from two flocks; Histopathologica examinations showing that most tracheas had very severe, acute tracheitis; Infection in most of the layer farms in the regions of Rabat, Temara by June 2003.