Abstract
Eighty-four cerebrospinal fluid (CSF) samples from different children who presented with signs and symptoms of meningitis were evaluated for the presence of Mycobacterium tuberculosis complex organisms by the Gen-Probe Amplified Mycobacterium tuberculosis Direct Test (MTD; Gen-Probe, San Diego, Calif.). All CSF samples had negative acid-fast smears by the Ziehl-Neelsen staining method. M. tuberculosis was recovered from five samples. M. tuberculosis did not grow from 19 additional samples, but the samples were from patients who fulfilled specific clinical and laboratory criteria for probable tuberculous meningitis (TBM). The remaining samples (n = 60) were from patients with other infections or noninfectious causes of meningitis. The results of the MTD were interpreted as positive or negative on the basis of recommended cutoff values for respiratory specimens. These results were interpreted as true or false positives or true or false negatives on the basis of the results of M. tuberculosis culture or whether the patient fulfilled criteria for probable TBM. The Gen-Probe MTD was 33% sensitive and 100% specific for detecting M. tuberculosis complex organisms in these 84 CSF samples. If the cutoff values for positive results were decreased for the MTD (≥11,000 versus ≥30,000 relative light units), the sensitivity increased to 83% and the specificity remained 100%. These results for the MTD are encouraging considering that TBM is a highly fatal disease and difficult to diagnose by conventional laboratory techniques.
Tuberculous meningitis (TBM) is the most serious form of extrapulmonary tuberculosis. The disease is frequently fatal if it is not treated early, and in surviving patients neurologic sequelae are common (6, 9–12, 26). In developing countries, TBM occurs in 7 to 12% of persons with active Mycobacterium tuberculosis infection (25). In developed countries, TBM occurs less frequently, but the incidence is increasing in association with the human immunodeficiency virus epidemic (3, 21).
The diagnosis of TBM is difficult due to the low numbers of mycobacteria in the cerebrospinal fluid (CSF) of patients with this disease. In several reported series of TBM in children, acid-fast smears and cultures of the first samples of CSF collected were positive for only 8 to 10% and 29 to 48% of the patients, respectively (5, 17, 19, 27). Tuberculin skin testing is also of limited diagnostic value for this condition (3, 17, 27).
Attention has focused on the development of alternative, rapid, accurate methods for the detection of M. tuberculosis in the CSF. Both indirect and direct assays have been evaluated. Examples of indirect assays include the assessment of the activity of adenosine deaminase, an enzyme that is produced by T lymphocytes and whose levels are elevated in patients whose CSF is infected with M. tuberculosis (sensitivity range, 60 to 100%; specificity range, 84 to 99%) (22, 23), the determination of the ratio of the concentration of bromide between the serum and the CSF after a loading dose of bromide is given (the ratio of the concentration of bromide in the serum to that in the CSF decreases with disruption of the blood-brain barrier, as occurs with TBM) (sensitivity, 80%; specificity, 95%) (29), and the measurement of antibody to tuberculin (purified protein derivative) in the CSF (sensitivity, 24%; specificity, 98%) (28). Potentially useful direct tests which have been evaluated include the analysis for mycobacterial structural components such as tuberculostearic acid (sensitivity, 95%; specificity, 98%) (8) or the detection of mycobacterial antigens (sensitivity, 39 to 100%; specificity, 96 to 99%) (10, 13, 28). However, all of these indirect and direct assays are relatively difficult to perform, lack standardization, and are not commercially available in kit formats.
Several investigators have demonstrated the utility of in-house nucleic acid amplification techniques for the detection of M. tuberculosis complex in CSF (7, 14, 15, 24). One commercial kit which is currently available for the detection of M. tuberculosis complex organisms in respiratory samples is the Gen-Probe Amplified Mycobacterium tuberculosis Direct Test (MTD; Gen-Probe, San Diego, Calif.). The objective of the current study was to determine the ability of the Gen-Probe MTD to detect M. tuberculosis complex organisms in 84 CSF samples.
MATERIALS AND METHODS
Subjects.
The subjects were children less than 15 years old who presented with signs and symptoms of meningitis from March 1995 through March 1996. All of the children were evaluated and followed throughout their admission at the Dr. Robert Reid Cabral Pediatric Hospital, a 350-bed university teaching hospital located in Santo Domingo, Dominican Republic. There were 358 cases of meningitis during this time period. Twenty-nine (8.1%) were ultimately diagnosed as TBM. Inclusion into the study was based on the ability to obtain an adequate sample for laboratory testing as described below and a complete clinical history, which consisted of symptoms and duration of illness, prior treatment, contact history, Mantoux skin test result, and response to treatment.
Clinical specimens.
CSF samples (n = 84) were obtained by lumbar puncture. CSF samples were centrifuged at 2,500 × g for 15 min, and the sediment was evaluated as described below.
Bacterial antigen testing.
All samples were screened by latex agglutination testing for Streptococcus pneumoniae, Haemophilus influenzae type b, Neisseria meningitidis groups A, C, Y, and W135, group B streptococcus (Streptococcus agalactiae), and Escherichia coli K1 and N. meningitidis group B according to the manufacturer’s instructions (bio-Merieux, St. Louis, Mo.).
Bacterial cultures.
All CSF specimens were cultured for general bacteria by inoculating sediment onto a blood and a chocolate agar. These plates were incubated at 35 to 37°C in CO2 for 2 days and were examined daily for bacterial growth. Bacteria were identified by standard techniques.
Definition of suspected TBM.
Patients with suspected TBM were those with fever and stiff neck for longer than 2 weeks, with analysis of CSF showing pleocytosis (>10 leukocytes/ml), an elevated protein concentration (>40 mg/dl), and an amount of glucose in CSF less than 60% of the amount of glucose in serum, and with negative bacterial antigen tests and cultures. In addition, the patients had to be positive for at least two of the following supporting criteria: (i) close contact (i.e., at least 2 days per week in the same domicile) with a patient with a known case of active tuberculosis, (ii) positive Mantoux skin test (i.e., induration, >5 mm), (iii) microbiologic or radiographic evidence of active tuberculosis at an extraneural site, (iv) clinical response to antituberculous drugs, or (v) cranial computed axial tomography showing central nervous system densities or basilar exudates. A clinical response to antituberculous drugs was defined as clinical improvement on a quadruple-drug regimen of isoniazid, rifampin, streptomycin, and pyrazinamide at standard doses. This improvement could occur following a lack of clinical improvement to standard dual-antibacterial therapy of chloramphenicol and ampicillin or when this standard antibacterial therapy was not used.
Mycobacteria cultures.
For patients with clinically suspected TBM, CSF sediment was resuspended by adding approximately 3 ml of prepared phosphate buffer at pH 6.8, and then an aliquot (500 μl) was inoculated into a single Lowenstein-Jensen slant tube and the tube was incubated at 35 to 36°C for 12 weeks. Any growth on this medium was confirmed as M. tuberculosis by Ziehl-Neelsen staining and conventional biochemical testing (18). An additional amount of CSF sediment was heat fixed onto a glass slide and was stained by the Ziehl-Neelsen method.
Patients with probable TBM were those who met the clinical and laboratory criteria defined above but who had negative test results for general bacteria and mycobacteria. Patients with bacteriologically proven TBM were those with confirmed growth of M. tuberculosis on Lowenstein-Jensen medium or those whose CSF had a positive Ziehl-Neelsen staining result.
MTD.
Portions of all CSF sediments were transported overnight on dry ice to the Mayo Clinic Microbiology Laboratory located in Rochester, Minn. Upon receipt, the samples were placed in a freezer at −70°C until they were further analyzed. CSF samples were processed and analyzed according to the manufacturer’s instructions for sputum, but with the following modifications adapted from Pfyffer and colleagues (20): (i) whenever possible, the amount of sample was increased 10-fold (500 μl was used instead of 50 μl; if there was an insufficient amount of sample, the total volume was increased to 500 μl with sterile water); (ii) the sample was pretreated with a denaturation agent (3.26% sodium dodecyl [lauryl] sulfate [SDS], 1.0% NaOH), (iii) and the nucleic acid amplification time was increased from 2 to 3 h. Cutoff values for a positive result were ≥30,000 relative light units (RLUs), as recommended by the manufacturer. Lower cutoff values for a positive result were also assessed.
RESULTS
None of the CSF samples had positive smears by Ziehl-Neelsen staining. M. tuberculosis was isolated from five specimens. M. tuberculosis was not recovered from 19 specimens, but these were from patients who fulfilled the criteria for probable TBM. Table 1 presents the specific supporting criteria for each of the 19 patients with probable TBM listed according to RLU value. Three of the 19 patients met two of the supporting criteria, 12 of the 19 patients met three of the supporting criteria, and 4 of the 19 patients met four of the supporting criteria. All CSF specimens from patients with probable TBM had elevated leukocyte counts (mean, 435 × 109 ± 326 × 109/liter), elevated protein concentration (mean, 206 ± 100 g/dl), and a CSF glucose concentration less than 60% of the blood glucose concentration (mean, 35 ± 11 mg/dl). Eighty percent of the patients with probable TBM had a lymphocytic predominance in their CSF.
TABLE 1.
Supporting criteria for 19 patients with probable TBM and Gen-Probe MTD RLUs
| RLUs and exposure to a patient with tuberculosis | Mantoux skin test reactivity | Evidence of extraneural tuberculosis | Response to antituber- culous therapy | Findings on cranial computed tomography scan |
|---|---|---|---|---|
| >30,000 RLUs | ||||
| None | Negative | Chest X ray: miliary infiltrate | Improved | Basal exudates |
| Yes | Negative | Chest X ray: hilar adenopathy and perihilar infiltrates; sputum culture: M. tuberculosis | Died on day 2 of therapy | |
| Yes | Positive | Chest X ray: primary complex and hilar adenopathy | Died on day 3 of therapy | |
| Yes | Positive | Chest X ray: miliary infiltrate | Died on day 2 of therapy | |
| >20,000 and ≤30,000 RLUs | ||||
| Yes | Negative | Chest X ray: hilar adenopathy and perihilar infiltrate | Improved | |
| None | Positive | Chest X ray: miliary infiltrate and cavitation | Improved | |
| Yes | Positive | None | Improved | |
| Yes | Negative | Sputum culture: M. tuberculosis | Died on day 2 of therapy | |
| Yes | Positive | Chest X ray: hilar adenopathy | Improved | |
| Yes | Negative | Sputum culture: M. tuberculosis | Improved | |
| >15,000 and ≤20,000 RLUs | ||||
| Yes | Negative | None | Improved | Hypodense infiltrates |
| Yes | Negative | Chest X ray: hilar adenopathy | Improved | |
| No | Positive | Chest X ray: miliary infiltrate | Improved | |
| Yes | Positive | Chest X ray: hilar adenopathy | Died on day 2 of therapy | |
| Yes | Negative | Chest X ray: miliary infiltrate | Improved | |
| >12,000 and ≤15,000 RLUs | ||||
| Yes | Positive | Chest X ray: hilar adenopathy | Improved | |
| No | Negative | Chest X ray: primary complex | Improved | |
| Yes | Negative | Chest X ray: hilar adenopathy | Improved | |
| >11,000 and ≤12,000 RLUs | ||||
| Yes | Negative | Chest X ray: miliary infiltrate | Died on day 4 of therapy | Basal exudates, hypodensity, hydrocephalis |
In no patient was an M. tuberculosis complex organism detected by the Gen-Probe MTD when criteria for probable TBM were not fulfilled or when other bacteria were isolated or other infectious agents were felt to be responsible for meningitis. Therefore, the MTD was 100% specific (Tables 2 and 3). For cases in which M. tuberculosis was isolated from the CSF or patients fulfilled the criteria for probable TBM, the sensitivity of the MTD was 33%. Lowering of the cutoff value for a positive result to approximately one-third of the recommended value improved the sensitivity of the MTD. Not shown in Table 3 are additional calculations for sensitivity and specificity when the cutoff values were decreased further. These calculations demonstrated that the sensitivities of the MTD remained essentially unchanged, but the specificities were appreciably worse.
TABLE 2.
Detection of M. tuberculosis in 84 CSF samples by Gen-Probe MTD
| Laboratory or clinical diagnosis | Total no. of samples evaluated | No. of samples positive by Gen-Probe MTD |
|---|---|---|
| Infectious agent detected in CSF by culture or immunologic techniques | ||
| Haemophilus influenzae | 16 | 0 |
| Mycobacterium tuberculosis | 5 | 4 |
| Streptococcus pneumoniae | 8 | 0 |
| Pseudomonas aeruginosa | 5 | 0 |
| Neisseria meningitidis | 2 | 0 |
| Escherichia coli | 3 | 0 |
| Staphylococcus aureus | 3 | 0 |
| Streptococcus agalactiae | 2 | 0 |
| Salmonella spp. | 1 | 0 |
| Serratia marcescens | 1 | 0 |
| Treponema pallidum | 1 | 0 |
| No infectious agent identified in CSF but meningitis part of systemic infection | ||
| Clostridium tetani | 2 | 0 |
| Varicella-zoster virus | 4 | 0 |
| Mumps virus | 1 | 0 |
| Human immunodeficiency virus | 1 | 0 |
| Other | ||
| Samples from patients with negative bacterial cultures but who were treated with antimicrobial agents for presumed bacterial meningitis | 8 | 0 |
| Samples from patients with negative bacterial cultures but probable TBM on the basis of clinical criteriaa | 19 | 4 |
| Noninfectious causes of meningitis, central nervous system tumors | 2 | 0 |
| Total | 84 | 8 |
Refer to Materials and Methods section for definition of probable TBM.
TABLE 3.
Gen-Probe MTD compared with mycobacterial culture and clinical assessment of patients
| RLU cutoff and Gen-Probe MTD result | No. of patients from whose CSF M. tuberculosis was cultured or with a clinical diagnosis of probable TBMa
|
Sensitivity (%) | Specificity (%) | Positive predictive value (%) | Negative preductive value (%) | |
|---|---|---|---|---|---|---|
| Positive | Negative | |||||
| Cutoff, ≥30,000 RLUs | ||||||
| Positive | 8 | 0 | 33 | 100 | 100 | 79 |
| Negative | 16 | 60 | ||||
| Cutoff, ≥11,000 RLUs | ||||||
| Positive | 20 | 0 | 83 | 100 | 100 | 94 |
| Negative | 4 | 60 | ||||
Refer to Materials and Methods section for definition of probable TBM.
DISCUSSION
Cultures of spinal fluid for M. tuberculosis are frequently negative for patients with TBM. Therefore, in the current study, the results of the Gen-Probe MTD were compared to those of a “gold standard” arbitrarily defined as either a positive CSF culture result for M. tuberculosis or clinical or laboratory criteria supporting a diagnosis of probable TBM. These criteria have been reported elsewhere and include contact history (exposure to persons with active tuberculosis), skin testing, the presence of extraneural tuberculosis, response to antituberculosis treatment, characteristic cranial computed tomography findings, and the results of CSF cellular and chemistry analyses (1, 4, 5, 17). In the current study, all patients that we felt had probable TBM had negative results for bacterial antigen tests and negative cultures for general pathogenic bacteria but had elevated leukocyte counts, elevated protein concentrations, and decreased glucose concentrations in the spinal fluid and were positive for at least two of the clinical criteria given above.
The results of our study demonstrate that the Gen-Probe MTD is a useful rapid test for the diagnosis of TBM. Four of the five CSF samples that grew M. tuberculosis were positive by the Gen-Probe MTD. An additional four samples were positive by the Gen-Probe MTD; all of these patients were felt to have probable TBM. It is possible that M. tuberculosis would have been isolated by culture from these four samples had liquid medium been used, although this was not available at the site where the samples were collected in the Dominican Republic. Due to the cost, space, and technology required, the use of liquid medium-based culture systems was not possible. The sensitivity of this rapid molecular test was greater than that of acid-fast smear examination; none of the CSF samples that were evaluated had positive acid-fast smear results.
The sensitivity of the Gen-Probe MTD was significantly increased (33 to 83%) and the specificity remained unchanged (100%) when the cutoff value for a positive result was decreased from ≥30,000 RLUs (used for respiratory specimens) to ≥11,000 RLUs. Further decreases in the cutoff values resulted in essentially no change in sensitivity, but the specificities were appreciably worse.
The specimen processing that we used for the Gen-Probe MTD for CSF samples was modified from that recommended for sputum samples. These modifications were according to a recent study by Pfyffer and colleagues (20). Those investigators showed that the pretreatment of CSF with the denaturing agent SDS–1% NaOH and an increase in the amplification time from 2 to 3 h improved the sensitivity of the Gen-Probe method. SDS denatures protein and enzymes which likely inhibit the nucleic acid amplification reactions. Also in accordance with the recommendations of Pfyffer and colleagues (20), whenever possible we processed 10 times the volume of CSF suggested by the manufacturer (500 versus 50 μl). For 4 of the 19 patients with probable TBM, 50 to 250 μl of CSF was processed; for 2 of the 5 patients culture positive for TBM, 250 μl was processed. Five hundred microliters was processed for each of the 13 remaining patients with probable TBM. These aliquots of CSF were treated with SDS-NaOH and centrifuged, the sediment was resuspended, and the usual test protocol was then followed. Pfyffer and colleagues (20) demonstrated that these modifications enhanced the sensitivity of the MTD for the detection of M. tuberculosis complex organisms in CSF spiked with the organism. Positive MTD results could be obtained for CSF spiked with as few as about five mycobacterial cells per ml (20).
The results that we obtained by the Gen-Probe MTD were in agreement with those of a smaller clinical evaluation published recently by Pfyffer and colleagues (20). They demonstrated that the Gen-Probe MTD was more sensitive than acid-fast smears for the detection of M. tuberculosis in six CSF specimens which were obtained from patients with clinical symptoms and chemical parameters compatible with TBM. One of these six CSF samples was acid-fast smear positive; five grew M. tuberculosis. Pfyffer and colleagues (20) evaluated fresh CSF samples by the Gen-Probe MTD method. It is possible that in our study the sensitivity of the Gen-Probe MTD method would have been enhanced if fresh specimens had been provided and specimens of 500 μl had consistently been evaluated. Freezing and thawing may theoretically affect RNA stability, which may ultimately result in decreased RLU values. Because of a lack of resources on site in the Dominican Republic, CSF samples were frozen, transported to the Mayo Clinic laboratory, and then evaluated.
Commercially prepared, standardized rapid test methods whose performance is equal to or exceeds the performance of acid-fast smears for diagnosing TBM are not available. The results of this study and the study of Pfyffer and colleagues (20) demonstrate that for the diagnosis of TBM, the Gen-Probe MTD is superior to acid-fast staining. Savings in reagent costs and personnel time could be realized if the Gen-Probe MTD were used in place of acid-fast staining for the rapid diagnosis of this disease. Like acid-fast staining, the Gen-Probe should be used only for those patients in whom TBM is suspected (2, 16). The Gen-Probe MTD is approved by the U.S. Food and Drug Administration and is commercially available for the testing of respiratory specimens. Modification of this test method for CSF specimens to include changes in sample preparation and interpretive changes in cutoff values should facilitate the rapid diagnosis of TBM, a frequently fatal illness.
REFERENCES
- 1.Ahuja G K, Mohan K K, Prasad K, Behari M. Diagnostic criteria for tuberculous meningitis and their validation. Tubercle Lung Dis. 1994;75:149–152. doi: 10.1016/0962-8479(94)90045-0. [DOI] [PubMed] [Google Scholar]
- 2.Albright R E, Graham C B, Christenson R H, Schell W A, Bledsoe M C, Emlet J L, Mears T P, Reller L B, Schneider K A. Issues in cerebrospinal fluid management. Am J Clin Pathol. 1991;95:418–423. doi: 10.1093/ajcp/95.3.418. [DOI] [PubMed] [Google Scholar]
- 3.Benengher J, Moreno S, Laguna F, Vincente T, Adrados M, Ortega A, González-La Hoz J, Bouza E. Tuberculous meningitis in patients infected with HIV. N Engl J Med. 1992;326:668–672. doi: 10.1056/NEJM199203053261004. [DOI] [PubMed] [Google Scholar]
- 4.Curless R G, Mitchell C D. Central nervous system tuberculosis in children. Pediatr Neurol. 1991;7:270–274. doi: 10.1016/0887-8994(91)90044-l. [DOI] [PubMed] [Google Scholar]
- 5.Davis L E, Kamal R R, Lambert L C, Skipper B J. Tuberculous meningitis in the southwestern United States: a community-based study. Neurology. 1993;43:1775–1778. doi: 10.1212/wnl.43.9.1775. [DOI] [PubMed] [Google Scholar]
- 6.Doerr C A, Starke J R, Ong L T. Clinical and public health aspects of tuberculous meningitis in children. J Pediatr. 1995;127:27–33. doi: 10.1016/s0022-3476(95)70252-0. [DOI] [PubMed] [Google Scholar]
- 7.Donald P R, Victor T C, Jordaan A M, Schoeman J F, Van Helden P D. Polymerase chain reaction in the diagnosis of tuberculous meningitis. Scand J Infect Dis. 1994;25:613–617. doi: 10.3109/00365549309008550. [DOI] [PubMed] [Google Scholar]
- 8.French G L, Chan C Y, Cheung S W, Teoh R, Humphries M J, O’Mahony G. Diagnosis of tuberculous meningitis by detection of tuberculostearic acid in cerebrospinal fluid. Lancet. 1987;ii:117–119. doi: 10.1016/s0140-6736(87)92328-2. [DOI] [PubMed] [Google Scholar]
- 9.Humphries M J, Teoh R, Lau J, Gabriel M. Factors of prognostic significance in Chinese children with tuberculous meningitis. Tubercle. 1990;71:161–168. doi: 10.1016/0041-3879(90)90069-k. [DOI] [PubMed] [Google Scholar]
- 10.Kadival G V, Samuel A M, Mazarelo T B M S, Chaparas S D. Radioimmunoassay for detecting Mycobacterium tuberculosis antigen in cerebrospinal fluids of patients with tuberculous meningitis. J Infect Dis. 1987;155:608–611. doi: 10.1093/infdis/155.4.608. [DOI] [PubMed] [Google Scholar]
- 11.Kent S J, Crowe S M, Yung A, Lucas C R, Mijch A M. Tuberculous meningitis: a 30-year review. Clin Infect Dis. 1993;17:987–994. doi: 10.1093/clinids/17.6.987. [DOI] [PubMed] [Google Scholar]
- 12.Klein N C, Damsker B, Hirschman S Z. Mycobacterial meningitis: retrospective analysis from 1970 to 1983. Am J Med. 1985;79:29–34. doi: 10.1016/0002-9343(85)90542-x. [DOI] [PubMed] [Google Scholar]
- 13.Krambovitis E, McIllmurray M B, Lock P E, Hendrickse W, Holzel H. Rapid diagnosis of tuberculous meningitis by latex particle agglutination. Lancet. 1984;ii:1229–1231. doi: 10.1016/s0140-6736(84)92792-2. [DOI] [PubMed] [Google Scholar]
- 14.Lee B W, Tan J A M A, Wong S C, Tan C B, Yap H K, Low P S, Chia J N, Tay J S H. DNA amplification by the polymerase chain reaction for the rapid diagnosis of tuberculous meningitis. Comparison of protocols involving three mycobacterial DNA sequences: IS6110, 65KD antigen, and MPB64. J Neuro Sci. 1994;123:173–179. doi: 10.1016/0022-510x(94)90220-8. [DOI] [PubMed] [Google Scholar]
- 15.Liu P Y, Shi Z Y, Lau Y J, Hu B S. Rapid diagnosis of tuberculous meningitis by a simplified nested amplification protocol. Neurology. 1994;44:1162–1164. doi: 10.1212/wnl.44.6.1161. [DOI] [PubMed] [Google Scholar]
- 16.Morris A J, Smith L K, Mirrett S, Reller L B. Cost and time savings following introduction of rejection criteria for clinical specimens. J Clin Microbiol. 1996;34:355–357. doi: 10.1128/jcm.34.2.355-357.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Newton R W. Tuberculous meningitis. Arch Dis Child. 1994;70:364–366. doi: 10.1136/adc.70.5.364. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Nolte F S, Metchock B. Mycobacterium. In: Murray P R, Baron E J, Pfaller M F, Tenover F C, Yolken R H, editors. Manual of clinical microbiology. 6th ed. Washington, D.C: ASM Press; 1995. pp. 400–437. [Google Scholar]
- 19.Ogawa S K, Smith M A, Brennessel D, Lowy F D. Tuberculous meningitis in an urban medical center. Medicine (Baltimore) 1987;66:317–326. doi: 10.1097/00005792-198707000-00004. [DOI] [PubMed] [Google Scholar]
- 20.Pfyffer G E, Kissling P, Jahn E M I, Welscher H-M, Salfinger M, Weber R. Diagnostic performance of amplified Mycobacterium tuberculosis direct test with cerebrospinal fluid, other nonrespiratory, and respiratory specimens. J Clin Microbiol. 1996;34:834–841. doi: 10.1128/jcm.34.4.834-841.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Raviglione M C, Snider D E, Kochi A. Global epidemiology of tuberculosis: morbidity and mortality of a worldwide epidemic. JAMA. 1995;273:220–225. [PubMed] [Google Scholar]
- 22.Ribera E, Martinez-Vazquez J M, Ocaña I, Segura R M, Pascual C. Activity of adenosine deaminase in cerebrospinal fluid for the diagnosis and follow-up of tuberculous meningitis in adults. J Infect Dis. 1987;155:603–607. doi: 10.1093/infdis/155.4.603. [DOI] [PubMed] [Google Scholar]
- 23.Segura R M, Pascual C, Ocaña I, Martinez-Vazquez J M, Ribera E, Ruiz I, Pelegrí M D. Adenosine deaminase in body fluids: a useful diagnostic tool in tuberculosis. Clin Biochem. 1989;22:141–148. doi: 10.1016/s0009-9120(89)80013-x. [DOI] [PubMed] [Google Scholar]
- 24.Seth P, Ahuja G K, Vijaya Bhanu N, Behari M, Bhowmik S, Broor S, Dar L, Chakraborty M. Evaluation of polymerase chain reaction for rapid diagnosis of clinically suspected tuberculous meningitis. Tubercle Lung Dis. 1996;77:353–357. doi: 10.1016/s0962-8479(96)90101-x. [DOI] [PubMed] [Google Scholar]
- 25.Shankar P, Manjunath N, Mohan K K, Prasad K, Behari M, Ahuja G K. Rapid diagnosis of tuberculous meningitis by polymerase chain reaction. Lancet. 1991;337:5–7. doi: 10.1016/0140-6736(91)93328-7. [DOI] [PubMed] [Google Scholar]
- 26.Smith M H D, Starke J R, Marquis J R. Tuberculosis and opportunistic mycobacterial infections. In: Feign R D, Cherry J D, editors. Textbook of pediatric infectious diseases. Philadelphia, Pa: The W. B. Saunders Company; 1992. pp. 1321–1362. [Google Scholar]
- 27.Stamos J K, Rowley A H. Pediatric tuberculosis: an update. Curr Probl Pediatr. 1995;25:131–136. doi: 10.1016/s0045-9380(06)80048-4. [DOI] [PubMed] [Google Scholar]
- 28.Watt G, Zaraspe G, Basutista S, Laughlin L W. Rapid diagnosis of tuberculous meningitis by using an enzyme-linked immunosorbent assay to detect mycobacterial antigen and antibody in cerebrospinal fluid. J Infect Dis. 1988;158:681–686. doi: 10.1093/infdis/158.4.681. [DOI] [PubMed] [Google Scholar]
- 29.Wiggelinkhuizen J, Mann M. The radioactive bromide partition test in the diagnosis of tuberculous meningitis in children. J Pediatr. 1980;97:843–847. doi: 10.1016/s0022-3476(80)80286-1. [DOI] [PubMed] [Google Scholar]