The H9N2 virus continues to spread in wild birds and poultry worldwide. At the beginning of 2016, the H9N2 Avian influenza virus (AIV) was detected in Morocco for the first time; despite the implementation of vaccination strategies to control the disease, the virus has become endemic in poultry in the country. The present study was carried out to investigate the origins, zoonotic potential, as well as the impact of vaccination on the molecular evolution of Moroccan H9N2 viruses. Twenty-eight (28) H9N2 viruses collected from 2016 to 2021 in Moroccan poultry flocks were isolated and their whole genomes sequenced. Phylogenetic and evolutionary analyses showed that Moroccan H9N2 viruses belong to the G1-like lineage and are closely related to viruses isolated in Africa and the Middle East. A high similarity among all the 2016–2017 hemagglutinin sequences was observed, while the viruses identified in 2018–2019 and 2020–2021 were separated from their 2016–2017 ancestors by long branches. Mutations in the HA protein associated with antigenic drift and increased zoonotic potential were also found. The Bayesian phylogeographic analyses revealed the Middle East as being the region where the Moroccan H9N2 virus may have originated, before spreading to the other African countries. Our study is the first comprehensive analysis of the evolutionary history of the H9N2 viruses in the country, highlighting their zoonotic potential and pointing out the importance of implementing effective monitoring systems.

The aim of the present study was to evaluate hepatitis A virus (HAV) and hepatitis E virus (HEV) contamination in mussels (Mytilus galloprovincialis) from Cherrat estuary (Moroccan Atlantic Coast), Morocco. In total, 52 samples (n=12 mussels/each) were collected at four sites in the estuary, monthly, between March 2019 and March 2020. HAV and HEV were detected by real-time reverse transcription polymerase chain reaction (RT-PCR) according to the ISO/TS 15216 method. HAV was detected in 46.15 of analyzed samples. Conversely, HEV was not detected in any sample. Moreover, the HAV detection rate was significantly associated with seasonal rainfall variations. This qualitative study on HAV and HEV contamination highlights the interest of studying mussel samples from wild areas. As HAV presence in mussels represents a potential health risk, viral contamination surveillance of mussels is necessary to protect consumers. HAV shellfish contamination must be monitored at Cherrat estuary because of the role played by shellfish as HAV reservoirs and/or vehicles in fecal-oral HAV transmission.

Perspectivas filogenéticas y dinámica específica del hospedador del metapneumovirus aviar en aves silvestres marroquíes. El metapneumovirus aviar (MPVa) representa una amenaza significativa para la salud de las aves comerciales, causando enfermedades respiratorias, reducción de la producción de huevos y pérdidas económicas sustanciales. A pesar de su importancia mun-dial, los datos sobre la circulación del MPVa en el norte de África siguen siendo limitados. Este estudio investigó la prevalencia y la diversidad genética del MPVa en aves silvestres de Marruecos, centrándose en las especies migratorias. Las pruebas moleculares detectaron MPVa en el 12% de las muestras (131 aves, 254 muestras); el subtipo B representó el 73 % de los casos positivos y el subtipo A el 27%. El análisis filogenético reveló estrechas relaciones genéticas entre las cepas marroquíes y las cepas de referencia europeas, incluyendo secuencias relacionadas con la vacuna. Las cepas aisladas de diferentes especies de aves se agruparon en grupos filogenéticos distintos, lo que sugiere posibles adaptaciones específicas del hospedador. Estos hallazgos subrayan el papel de las aves migratorias en la diseminación del aMPV y resaltan la necesidad urgente de mejorar la vigilancia para orientar las estrategias de control de las poblaciones de aves tanto silvestres como domésticas.

Background: Wild birds, particularly migratory species, can act as natural reservoirs and vectors of avian orthoavulavirus type 1 (AOAV-1) or Newcastle disease virus (NDV), contributing to its spread across regions and potentially threatening domestic poultry populations. AOAV-1, also known as NDV, is a major pathogen affecting avian species and poses a global threat to poultry production. It belongs to the Paramyxoviridae family and is an RNA virus encoding six key proteins, including the fusion (F) protein, which determines pathogenicity. AOAV-1 is classified into three pathotypes based on virulence: velogenic (highly pathogenic), mesogenic (moderately pathogenic), and lentogenic (mild or asymptomatic). In Morocco, AOAV-1 is endemic in poultry production systems, as evidenced by recent studies reporting a 52.1% seroprevalence and active viral RNA detection in backyard chickens in the Khemisset and Skhirat-Temara provinces; however, effective vaccination strategies have contributed to controlling the clinical signs and widespread dissemination of the virus. Aim: The main objective of this study was to investigate the presence of AOAV-1 in wild bird populations across Morocco, providing insights into possible transmission of infection affecting domestic poultry. Methods: From November 2016 to April 2022, a total of 1984 samples were collected from 840 individual birds, encompassing 79 species, 25 families, and 12 orders. The majority of the samples belonged to Charadriiformes, Anseriformes, Pelecaniformes, and Passeriformes. Sampling was conducted at 17 wetlands and six additional locations throughout Morocco. Viral detection was performed using real-time reverse transcriptase PCR (RT-qPCR) targeting Matrix (M) and RNA polymerase (L) genes to confirm the presence of AOAV-1. Results: Although the study spanned 6 years and included a large number of samples from bird orders considered primary AOAV-1 reservoirs, all samples tested negative for NDV RNA using both M and L gene targets. Conclusion: This study represents the first effort in Morocco to monitor wild birds for AOAV-1. The samples analyzed were initially collected for avian influenza surveillance, which shares epidemiological similarities with Newcastle’s disease. However, to improve future surveillance efforts, sample collection should be optimized to target scenarios with the highest probability of virus detection.

Mussels filter large amounts of water to extract nutrients; therefore, they can concentrate and accumulate in their tissues infectious agents, and vectors of enteric diseases. The aim of this study was to assess mussel contamination by Norovirus genogroups I and II in the Cherrat estuary to determine the public health risk linked to their consumption. Mussels (Mytilus galloprovincialis) were collected (n=52 samples; 12 mussels/sample) at four sites (S1 and S2 located on the right rocky bank / S3 and S4, located on the rocky left bank) in the Cherrat estuary (Casa-Settat region), Morocco, during 13 months, from March 2019 to March 2020. Norovirus was detected and quantified by real-time Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Norovirus genogroups I and II were detected in 17.30% and 94.23% of mussel samples, respectively. Contamination by Norovirus (genogroups I and II) was not correlated with seasonal factors (month and rainfall), and Norovirus prevalence was comparable among the four sampling sites. Consumption of raw or undercooked mussels contaminated with Norovirus can cause gastroenteritis, which represents a potential risk to human health. The present study would be helpful to control and manage the potential risk to the public health of the Moroccan population due to the degradation of water quality continuously impacted by runoff, the urban wastewater treatment system malfunctions, and overflows from nearby sewage systems.

BVDV is one of the most important pathogens worldwide. Molecular data on this pathogen remain insufficient in North African cattle. We aim to report the molecular detection and the genetic characterization of BVDV in Cattle with Clinical Respiratory Symptoms in Morocco. We collected nasal swabs from 200 cattle with respiratory signs in the Casablanca-Settat region. Each sample was subjected to individual BVDV screening using the real-time RT-PCR assay, targeting the 5′UTR. We performed conventional RT-PCR, targeting the 5′UTR and Npro genes, and sequenced the amplified Three positive samples via the Sanger method. Reference BVDV genotypes from GenBank were included in the phylogenetic analysis. Of the nasal swabs collected, 2.5% (5/200) were found positive to BVDV through real-time RT-PCR, and the results were confirmed by conventional PCR targeting the Npro and 5'UTR genes. Sanger sequencing of three positive samples focusing on the 5′ UTR and Npro regions led to the detection of two positive samples for the BVDV-2 genotype and one sample positive for the BVDV-1 genotype. The phylogenetic analysis reveals that the BVDV-1 isolate belongs to the European BVDV-1 clade. Furthermore, BVDV-2 isolate represents a distinct sub-genotype or a geographically unique variant of BVDV-2.The study estimates the occurrence of BVDV in respiratory symptomatic cattle and provides the first molecular evidence of BVDV-1 and BVDV-2 in Morocco. This finding could be significant for the epidemiology, diagnosis, and control of BVDV infection in Morocco.