COMPARISON OF ZIEHL–NEELSEN BASED LIGHT MICROSCOPY WITH LED FLUORESCENT MICROSCOPY FOR TUBERCULOSIS DIAGNOSIS: AN INSIGHT FROM A LIMITED RESOURCE-HIGH BURDEN SETTING

Muhammad Yahya Noori, Faiza Ali, Zaheer Ali, Shaheen Sharafat

Abstract


Background: Microscopy is the most widely used tool for Tuberculosis screening.  Conventionally, Ziehl-Neelsen (ZN) staining has been the widely used for staining Acid-Fast Bacilli (AFB) but with the advent of Fluorescent staining, Auramine O stain is now being adapted as the preferred method for setups with high workload as it has the advantage of being less laborious, since bacteria fluoresce in front of a dark background and are easier to count. This study was performed to compare the efficiency of the two methods in a high-burden, limited resource setting to see the magnitude of diagnostic accuracy between ZN and Fluorescent Microscopy, using culture as the standard. Methods: Altogether 987 culturally confirmed cases were considered from the period 36 months during January 2011 to December 2013 and data were compiled from the records maintained at the Provincial Tuberculosis Reference Laboratory at Ojha Institute of Chest Diseases, Dow University of Health Sciences, Karachi.  The results from 523 cases examined using ZN and 464 cases using Fluorescent staining method were compared for diagnostic accuracy on the basis of Mycobacterial culture results. Smears are prepared from the clinical samples obtained from presumptive tuberculosis patients. Results: The results of ZN method showed 94.23% [95% CI 91.32–96.39%] sensitivity and 84.91% [95% CI 78.38–90.08%] specificity.  While FM showed a sensitivity of 97.15% [95% CI 94.82–98.63%] and specificity of 83.19% [95% CI 74.99–89.56%]. Conclusions: The results showed that Fluorescent microscopy was slightly more sensitive than ZN light Microscopy, while specificity of both the methods were comparable.

Keywords: Mycobacterium tuberculosis, Acid fast bacilli, Tuberculosis, Ziehl-Neelsen (ZN) staining, Auramine O Fluorescent staining

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References


WHO. Global tuberculosis report 2015. [Internet]. [cited 2016 May 1]. Available from: http://apps.who.int/iris/bitstream/10665/191102/1/9789241565059_eng.pdf

Zaib-un-Nisa, Javed H, Zafar A, Qayyum A, Rehman A, Ejaz H. Comparison of fluorescence microscopy and Ziehl-Neelsen technique in diagnosis of tuberculosis in paediatric patients. J Pak Med Assoc 2015;65(8):879–81.

Steingart KR, Henry M, Ng V, Hopewell PC, Ramsay A, Cunningham J, et al. Fluorescence versus conventional sputum smear microscopy for tuberculosis: a systematic review. Lancet Infect Dis 2006;6(9):570–81.

Collins CH, Grange JM, Yates M. Tuberculosis bacteriology: organization and practice. Butterworth Heinemann; 1997.

Hooja S, Pal N, Malhotra B, Goyal S, Kumar V, Vyas L. Comparison of Ziehl Neelsen & Auramine O staining methods on direct and concentrated smears in clinical specimens. Indian J Tuberc 2011;58(2):72–6.

Global Laboratory Initiative. Mycobacteriology laboratory manual. Geneva WHO Stop TB Partnersh. 2014.

Winn WC, Koneman EW, editors. Koneman’s color atlas and textbook of diagnostic microbiology. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2006.

FIND. Partnering for better diagnosis for all. Foundation for Innovative Diagnostics. [Internet]. [cited 2015 may 1]. Available from: https://www.finddx.org/wp-content/uploads/2016/04/delivering-on-the-promise-Sep2008.pdf

Laifangbam S, Singh HL, Singh NB, Devi KM, Singh NT. A comparative study of fluorescent microscopy with Ziehl-Neelsen staining and culture for the diagnosis of pulmonary tuberculosis. Kathmandu Univ Med J (KUMJ) 2009;7(27):226–30.

Salam AA, Rehman S, Munir MK, Iqbal R, Saeed SS, Khan SU. Importance of Ziehl-Neelsen Smear and Culture on Lowenstein Jensen Medium in Diagnosis of Pulmonary Tuberculosis. Pak J Chest Med 2014;20(2).

MedCalc. Statistical Software, Update 2014. [Internet]. [cited 2015 May 1]. Available from: www.medcalc.org

Minion J, Pai M, Ramsay A, Menzies D, Greenaway C. Comparison of LED and conventional fluorescence microscopy for detection of acid fast bacilli in a low-incidence setting. PLoS One 2011;6(7):e22495.

Ba F, Rieder HL. A comparison of fluorescence microscopy with the Ziehl-Neelsen technique in the examination of sputum for acid-fast bacilli. Int J Tuberc Lung Dis 1999;3(12):1101–5.

Trusov A, Bumgarner R, Valijev R, Chestnova R, Talevski S, Vragoterova C, et al. Comparison of Lumin LED fluorescent attachment, fluorescent microscopy and Ziehl-Neelsen for AFB diagnosis. Int J Tuberc Lung Dis 2009;13(7):836–41.

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