Journal Review
Journal Review
Treatment of MDR-TB meningitis
By Carol Kemper, MD, FACP
Clinical Associate Professor of Medicine
Stanford University
Stanford, CA
Source: Berning S, et al. Clin Infect Dis 2001; 32:643-646.
Berning and colleagues at the National Jewish Medical Center in Denver describe an unusual case of widely disseminated multidrug-resistant tuberculosis (MDR-TB) resulting in meningitis in an HIV-positive man. The patient ultimately responded to intrathecal administration of levofloxacin and amikacin, in addition to systemic therapy.
During initial treatment with a 5-drug regimen including INH, ethambutol, pyrazinamide, cycloserine, and capreomycin, the patient developed progressive central nervous system disease with positive cerebrospinal fluid cultures, despite evidence of improvement in the lungs. Initial attempts at treatment with parenterally administered levofloxacin and amikacin were not successful. Ultimately, intrathecal treatment via an Omaya reservoir with both levofloxacin (maximal dose 1.5 mg) and azithromycin (maximal dose 5 mg), titrated to patient tolerance, on alternate days, resulted in improvement in CSF parameters within 8 days. Although CSF levels
of the 2 agents were lower than target levels, they exceeded the MIC of each agent. CSF:serum ratios of both agents were higher (82%-99%) for levofloxacin and 43% to > 200% for amikacin than published reports. The patient was doing well 12 months later, still on therapy. Therapeutic drug monitoring of CSF and serum levels proved helpful in making dosage adjustments.
What to do when AFB culture is lost?
By Alan D. Tice, MD, FACP
Infections Limited
Tacoma, WA
Source: Patnaik M, et al. Rapid detection of smear-negative Mycobacterium tuberculosis by PCR and sequencing for rifampin resistance with DNA extracted directly from slides. J Clin Microbiol 2001; 39:51-52.
Patnaik and associates of the research department of Specialty Laboratories in Santa Monica, CA, seem to have perfected a way to detect Mycobacterium tuberculosis from slides of expectorated sputum using polymerase chain reaction (PCR). They can even detect the gene for resistance to rifampin.
They studied routine specimens sent to their laboratory for mycobacteria stains and cultures. They also used a technique of eluting mycobacterial DNA from sputum slides, then sequenced the rpoB gene to determine rifampin resistance as well. The nested PCR method could be done with a turnaround time of 48 hours.
Of 47 sputum specimens submitted for acid-fast bacilli (AFB) smears and culture, 24 (51%) grew M. tuberculosis. Only 14 (58%) were detected by microscopic methods. All 24 were positive by the PCR technique. There were no false positives. PCR also detected all 5 strains with rifampin resistance.
If more specimens confirm these numbers, it could also be used for much more rapid results for the detection of M. tuberculosis as well as susceptibility testing.
Subscribe Now for Access
You have reached your article limit for the month. We hope you found our articles both enjoyable and insightful. For information on new subscriptions, product trials, alternative billing arrangements or group and site discounts please call 800-688-2421. We look forward to having you as a long-term member of the Relias Media community.