We reviewed different diagnostic methods of brucellosis in different livestock and humans. Bacteriological diagnosis, immunohistochemistry (an alternative technique for direct diagnosis) and different molecular methods for Brucella species genotyping are among the direct methods for diagnosis of brucellosis discussed in this review. The well-established indirect methods for diagnosis of brucellosis, serological and brucellin allergic skin tests were also critically conferred. Finally, for effective control and prevention of brucellosis around the world, the direct diagnostic methods are advised in order to develop vaccine against the circulating Brucella strain in the specific country.
