Fever of unknown origin in a patient treated with Bacillus Calmette-Guerin (BCG) for bladder urothelial carcinoma in situ

Koch's Bacillus bovis (Mycobacterium bovis) was made avirulent by special culture conditions, i.e., 230 passages on medium containing potatoes treated with bile salts. It has been used mainly to prevent tuberculosis. The vaccine was named after the bacteriologist Albert Calmette and the veterinarian Camille Guerin, i.e., Bacillus Calmette-Guerin (BCG).These researchers worked at the Pasteur Institute in Lille and launched the vaccine in 1921. Recently, BCG was used also for its non-specif ic immunostimulant action. Intravesical administration of BCG is an adjunctive therapy for the treatment of bladder cancer, which does not invade the muscle wall. We will discuss the clinical case of a patient who had fever of unknown origin for about 2 months and was resistant to treatment with multiple lines of antibiotics.