“…Acute infections are usually diagnosed by microscopic examination of blood smears, whereas subclinical chronic infections can be identified serologically [2]. In addition, the indirect fluorescent antibody test (IFAT) is one of the most commonly used methods for the diagnosis of B. bovis infection [3,4] and has been applied in epidemiological studies in a number of countries [5,6], but IFAT was rendered cumbersome and subjective [4,7].…”