First report on the seroprevalence of avian encephalomyelitis virus antibody in Sonali (cross-bred) chickens in Bogura, Bangladesh

Abstract

Objectives: The study intended to detect the presence and distribution of avian encephalomyelitis virus (AEV)-specific antibodies in Sonali (cross-bred) parent chickens regarding farm location, flock size, and age in Bogura district of Bangladesh, a Sonali chicken belt. Materials and methods: A total of 275 Sonali parent chickens’ blood samples were collected randomly from 39 flocks during laying age with a healthy and non-vaccination history against AEV. Blood samples were collected aseptically from the wing veins of chickens using 3-ml syringes and sera were separated. Then, the sera were transferred to the laboratory by maintaining a cool chain. Indirect enzyme-linked immunosorbent assay was used to detect the specific antibodies against AEV present in the sera samples. Results: Overall, 70.18% of the chickens were found seropositive for AEV antibodies. Based on the location, the highest seropositivity was recorded in Bogura Sadar [91.30%, confidence intervals (CI) 79.21%–97.58%], and the lowest was in the Adomdighi sub-district (45.45%, CI 29.49%–63.08%). For flock size, AEV seropositivity was significantly ( p < 0.05) higher in the large flock (82.22%, CI 72.74%–89.48%). Regarding age groups, the seropositivity of AEV was significantly ( p < 0.05) increased with chickens’ age. Higher seropositivity was noted in chickens aged >51 weeks (89.32%, CI 81.69%–94.55%). Conclusion: The results indicate that AEV is circulating in the environment, and chickens were exposed to the field strain of AEV. To the best of our knowledge, this is the first report on AEV in chickens in Bangladesh. Proper vaccination and standard farm biosecurity practice could minimize AEV infection in chickens. A detailed epidemiology study, detection, and characterization of the AEV would be essential for effective AEV infection control.

Avian encephalomyelitis virus in backyard chickens

“…The previous reports recorded a much higher seroprevalence of AEV than our study. The seroprevalence was 79% in a Brazilian study [ 28 ], 45%–91% in Bangladesh [ 29 ], 79.35% in the Tamil Nandu state of India [ 30 ], and 57.1% in Sudan [ 31 ]. Reports on the incidence of AEV described the recent detection of AEV in several countries.…”

“…Reports on the incidence of AEV described the recent detection of AEV in several countries. In 2021, AEV was first reported in Bangladesh [ 29 ]. The detected low incidence of AEV in this study might be associated with the low density of chicken flocks in the collected sample areas.…”

“…The detected low incidence of AEV in this study might be associated with the low density of chicken flocks in the collected sample areas. It has been suggested that seropositivity is associated with larger chicken flocks rather than smaller flocks [ 29 ]. The high prevalence in some areas and the first reporting of AEV suggest the potential spread of the virus in new territories and the emergence of an expanded host range, as well as the potential for viral epidemics.…”

Diva Molecular Detection of Suspected Case of Newcastle and Encephalomylitis Disease in Layers

“…Experimentally, the virulence of NDV is classified according to pathogenicity: into (velogenic, mesogenic, lentogenic, and asymptomatic) forms, the velogenic NDV (vvNDV) produce neurological signs with hemorrhagic lesions and/ or respiratory signs (12). While(AE) is one of the important viral diseases many avian young species with an economic impact on poultry production (3,7,30). The disease has neurological signs especially, tremors and ataxia is transmitted vertically and horizontally, and also caused 40-60% morbidity and a 25% mortality rate (21,22).…”