Fowl adenovirus infections: A comprehensive review of prevalence, pathogenesis, diagnosis, control, and economic impact

Fowl adenoviruses (FAdVs), used to be recognized as non-malignant pathogens, have now evolved into notable pathogens threatening global poultry productions. This review synthesizes current knowledge on the escalating challenges posed by FAdVs. There is already a wide variety of genetic types or strains within the virus population of the genus Aviadenovirus, FAdVs, where distinct serotypes are already present as the causative agent of Inclusion Body Hepatitis (IBH) and Hydropericardium Hepatitis Syndrome (HHS). These viruses are widely distributed throughout the globe, hypervirulent strains are arising particularly novel genotypes of FAdV-4, spreading from Asia into new regions. As these pathogens cause high mortality, decreased growth performance, carcass being unfit for consumption, and various measures are needed to be taken for controlling these pathogens by vaccination and other control measures, its economic impact is considerably significant. Intensive farming system, new virus strain formation via mutation and recombination, immunosuppressive co-infection worsening the health of host usually facilitates the appearance of these pathogens. Controlling these diseases is hard because of having different serotypes and prevention includes mainly maintaining proper biosecurity and specific vaccination against specific serotype of the virus. However, it is more important to conduct more research into cross-protective vaccines, improved molecular diagnostics, and enhanced global surveillance. This review focuses on the importance of integrating strategies to lessen the adverse effects of FAdVs, as it's endangering poultry health, economic sustainability, and food security.