First Seroprevalence Survey of Avian Reovirus in Broiler Breeders Chicken Flocks in Morocco

Avian reovirus (ARV) is a prevalent infectious agent that has the potential to cause respiratory and gastrointestinal illnesses in poultry, leading to substantial financial losses in the poultry sector. Until now, there have been no investigations conducted to examine the epidemiological status of ARV infections in Morocco. The aim of this study was to investigate the seroprevalence of ARV infections with respect to area, types of chickens (broiler breeder, and broiler), vaccination status, and age of chickens. A total of 826 serum samples were collected from 36 broiler and broiler breeder flocks, with 14 of them being unvaccinated, fromsix different regions of Morocco, namely Casablanca-Settat, Rabat-Salé-Kénitra, Tanger-Tétouan-Al Hoceïma, Oriental, Marrakech-Safi, and Fez-Meknès between 2021 and 2022.These serum samples were screened using a commercial indirect ELISA ARV antibody test kit (IDEXX REO). The study found that all tested flocks were positive for ARV-specific antibodies, indicating that the virus was present in these flocks. Out of the 826 serum samples tested, 782 were positive for ARV-specific antibodies. The overall prevalence of ARV infections in breeder and broiler flocks was calculated to be 94.6% ± 0.78. To summarize, the current study provides evidence of the widespread distribution of ARV infections in Morocco, suggesting that the poultry industry in the country is highly infected with ARV.