On diagnostic advantages of Vidal's reaction and its modification by Fischer

For more than 30 years, Vidal's reaction has been generally recognized by clinicians as a reliable method for serodiagnosis of typhoid fever. Recent years, however, have introduced a significant reservation in the assessment of its diagnostic advantages, which mainly depends on the fact that the Vidal reaction is positive in persons who have undergone anti-typhoid vaccinations. In view of this, I would like to share our clinical material and compare it with the literature data to draw the appropriate conclusions.