Low sensitivity of polymerase chain reaction for diagnosis of tuberculous meningitis in southeastern Brazil

two polymerase chain reaction (pcr) protocols showed low sensitivity (36% and 53% for tb amplicor and mpb64 nested pcr, respectively), when compared with classic microbiological methods (73% and 54% for ziehl-neelsen staining and culture, respectively), in the diagnosis of tuberculous meningitis in 91 patients in southeastern brazil. only three pcr-positive, microbiologically negative patients were found. analysis of sequential cerebrospinal fluid samples by nested pcr detected mycobacterium tuberculosis dna up to 29 days after the introduction of antituberculosis chemotherapy.