Chicken Astrovirus Infection: Minireview and Preliminary Serologic Evidence of Antigenically and Genetically Distinct Chicken Astroviruses in Nigerian Indigenous Chickens
Poultry have gradually assumed a very important role in the economy of many industrialized and developing countries. However, with the continued discovery of new viral agents affecting the poultry industry worldwide, it is important that stakeholders in the industry in Nigeria be updated about these emerging viral threats in order to better understand the dynamics of health and disease that affect the industry. This knowledge will engender research into the prevalence, distribution, pathogenicity and economic losses caused by these diseases, and ultimately lead to the design of prevention strategies and formulation of policies for effective control. This paper includes a review on chicken astrovirus (CAstV), a recently emerged virus that causes enteritis, retarded growth and poor productivity in chickens, with particular emphasis on the history, economic importance, epidemiology, diagnosis and control. In addition, the result of a preliminary serological survey of CAstV antibodies in Nigerian indigenous chickens in Ibadan, Oyo State is reported. Using the indirect immunofluorescence test with CAstV 612- and CAstV 11672-infected cells respectively, only 4% and 8% of the tested sera were positive for CAstV antibodies. Our findings provide the first serologic evidence of CAstV infection in Nigeria and indicate the circulation of, at least, two antigenically and genetically distinct CAstVs in the Nigerian poultry population. We conclude that the runting-stunting, retarded growth and poor productivity commonly seen in Nigerian indigenous chickens could be due, among other factors, to CAstV infections.
Keywords: Chicken astrovirus, growth retardation, indirect immunofluorescence, indigenous chickens, Nigeria