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In a meta-analysis of 10 studies, the BACTEC 960/MGIT and BACTEC 460 systems showed a sensitivity and specificity in detecting mycobacteria (1,381 strains from 14,745 clinical specimens) of 81.5 and 99.6% and 85.8 and 99.9%, respectively. Combined with solid media, the sensitivity of the two systems increased to 87.7 and 89.7%, respectively.Currently, a combination of conventional solid media with a broth-based method is the accepted reference standard for the diagnosis of mycobacterial infection (5, 26). Among the methods utilizing liquid media, the half-automated radiometric BACTEC 460 TB system (BACTEC 460) is widely accepted as the reference standard. This system, however, is also known for some well-established limitations, which include problems with the use of radioactive material, cumbersome manual loading and unloading, potential hazard of needle stick injury, risk of cross contamination, and lack of computerized data management.Recently, the BACTEC Mycobacteria Growth Indicator Tube System (BACTEC 960/MGIT), a newly developed nonradiometric, fully automated, continuously monitoring system, was introduced as an alternative to the radiometric BACTEC 460 for growth and detection of mycobacteria. The results of several comparative studies show that BACTEC 960/MGIT is a suitable tool for the detection of Mycobacterium tuberculosis and other mycobacterial species, though rather wide variations in diagnostic performance have been reported (1-3, 6, 10-14, 16-18, 21, 23-25, 27, 28, 30-35). To provide an evaluation of the quality of the available reports and an overall summary of the diagnostic accuracy of BACTEC 960/MGIT versus that of BACTEC 460, we performed a systematic review and metaanalysis.Literature search. The literature was searched for the period from January 1990 to June 2003 with the Medline, Embase, and Cochrane libraries. The studies were included for analysis if they compared the results of BACTEC 960/MGIT and BACTEC 460TB with and without solid media, they reported data on false-positive (sample flagged as positive without any microscopic or cultural evidence of acid-fast bacilli by subculture at the end of the incubation period), false-negative (negative test samples found positive on subculture), truepositive, and true-negative results separately; the results of the tests were compared against the reference standard, which was defined as a positive culture with at least one of the three systems used, and the comparison between tests was performed prospectively with the same series of patients from a relevant clinical population, defined as a group of individuals requiring routine microbiologic investigations for suspected pulmonary or extrapulmonary mycobacterial infections.Statistical analysis. To evaluate if variations between primary studies in test threshold had an influence on the accuracy of diagnostic procedures, we used receiver operator characteristic (ROC) curves (9,15,20,22).The common value of noncomparative binary outcomes, as sensitivity and specificity, were obtained by transf...

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We performed a meta-analysis to determine whether antifungal prophylaxis decreases infectious morbidity and mortality in liver transplant patients. We searched for randomized trials dealing with prophylaxis with systemic antifungal agents. We used a fixed effect model, with risk ratio (RR) and 95% confidence interval (CI); we assessed study quality for heterogeneity and publication bias. Six studies (5 double-blind), for a total of 698 patients, compared fluconazole, itraconazole, or liposomal amphotericin to placebo (5 studies) or oral nystatin. Prophylaxis reduced colonization (RR, 0.45; CI, 0.37-0.55), total proven fungal infections (RR, 0.31; CI, 0.21-0.46), which included both superficial (RR, 0.27; CI, 0.16-0.45) and invasive (RR, 0.33; CI, 0.18-0.59) infections, and mortality attributable to fungal infection (RR, 0.30; CI, 0.12-0.75). Prophylaxis did not affect overall mortality (RR, 1.06; CI, 0.69-1.64) or empiric treatment for suspected fungal infection (RR, 0.80; CI, 0.39-1.67). The beneficial effect of antifungal prophylaxis was predominantly associated with the reduction of Candida albicans infection and mortality attributable to C. albicans. Compared to controls, however, patients receiving prophylaxis experienced a higher proportion of episodes of non-albicans Candida, and in particular of C. glabrata. No beneficial effect on invasive Aspergillus infection was observed. In conclusion, our analysis shows a clear, though limited, beneficial effect of antifungal prophylaxis in liver transplant patients. Concerns about the selection of triazole-resistant Candida strains, however, are realistic, and the potential disadvantages of prophylaxis should be weighed against the established benefits.

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