False positive widal reaction in high-titer disseminated BCG infection

False-positive Widal reactions following certain non-typhoid Salmonella infections may occur commonly. The case of a patient who developed miliary tuberculosis secondary to intravesical bacillus Calmette-Guérin (BCG) immunotherapy for bladder carcinoma is described. Very high titers of typhoid and paratyphoid agglutinins were obtained with the Widal test; these titers returned to normal after successful anti-tuberculous treatment. This case of high-titer, false-positive Salmonella typhi and Salmonella paratyphi A and B reactions to BCG infection occurred in an area non-endemic for typhoid or paratyphoid fever.