Abstract:

A total of 340 specimens from 192 (56.5%) male and 148 (43.5%) females attending tuberculosis clinics in Abuja metropolis were analysed by five different laboratory techniques (ZN Direct, ZN Bleach, LJ slants, BACTEC and Serology TB) for the diagnosis of Mycobacterium tuberculosis. Comparative analysis of results at P=0.05, revealed that there was a statistical significant (X2=127.1, P<0.001) difference between the diagnosistic performance of the five laboratory techniques. A follow-up analysis based on the 95% confidence interval of pair differences in proportion between the five techniques indicated that the BACTEC assay was the major source of the difference(P<0.001) in pair methods. Comparison of the 95% confidence limit of pair differences in diagnostic specificity of Mycobacterium tuberculosis between ZN-BACTEC and other methods confirmed (P<0.001) the high detection rate of BACTEC. It was observed that BACTEC had the highest detection rate (61.2%), followed by LJ (31.2%), then ZN Bleach (30.3%) and ZN Direct (28.8%), while Serology had only 25.3% ZN BACTEC appeared to the most reliable, and time effective combination. ZN Bleach should be encouraged in poor resource settings in lieu of the conventional three standard smears for ZN Direct. The use of Serologic TB kit alone for the diagnosis of tuberculosis should be discouraged.

Keywords: Mycobacterium tuberculosis, BACTEC, Laboratory and Serology.

References:

[1]. Baker F. J. and Breach M. R. ;(1980) Mycobacteria: In medical microbiological techniques. Butterwort and co.ltd. 183-195.

[2]. Centre for Disease Control and Prevention, (1992). National action plan to combact multidrug- resistant tuberculosis. MMWR; 41 (NO. RR-11).

[3]. Centre for Disease Control and Prevention, (1995). Laboratory Practices for Diagnosis of Tuberculosis-United State in 1994; MMWR 44 (31); 587-589.

[4]. David N. Memurray, (1996). Mycobacteria and Norcardia: In Medical Microbioligy. 4th Edition. Samuel Brown (ed). The University of Texas Medical Branch Publishers, Galverston USA; 423-439.

[5]. Doern G.V. (1996) Diagnosis Mycobacteriology where are we today? J. Clin Microbiol; 34 : 1873 -1876.

[6]. Dye C., Schede S., Dolin P., Pathania V., Raviglione M.C., (1999).Consensus statement. Global burden of tuberculosis: estimated incidence, prevalence and mortality by country. WHO Global Sureveillance and Monitoring Project. JAMA; 269: 898-903-World Health Organisation(2002).