A comparative study of fluorescent microscopy with Ziehl-Neelsen staining and culture for the diagnosis of pulmonary tuberculosis (original) (raw)
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Background: Tuberculosis remains a major public health threat in Nepal and one of the leading causes of death from communicable diseases among adults. The majority of tuberculosis is pulmonary tuberculosis infecting lungs and sputum examination is important for this as it is the major way of transmission of disease. The diagnostic procedures rely on simple and inexpensive methods mostly of microscopy and culture examination. Therefore the evaluation of these diagnostic approaches has great importance. Objectives: To evaluate and compare the efficacy of Ziehl-Neelsen staining, Auramine O staining and culture of sputum samples for the diagnosis of pulmonary tuberculosis. Materials and methods: Total 299 sputum samples (170 samples from 78 Group I suspected cases with no treatment; 42 samples from 22 Group II DOTS follow-up cases; and 87 samples from 87 Group III MDR follow-up cases) were subjected to direct smear preparation each for ZN and AO staining for 1000x light microscopy and 400x fluorescent microscopy examination respectively and the remaining sample were further processed with NALC-NaOH method for culture on modified Lowenstein-Jensen Media for detection of Mycobacterium tuberculosis. Positive smears were graded according to IUATLD/WHO guideline. Result: Out of total 299 sputum samples of all types of cases, 19.06%, 29.1% and 24.41% were found pulmonary tuberculosis positive by ZN, AO and culture respectively. The case detection rates for suspected patients with no treatment were 20%, 25.88% & 28.24%; for DOTS follow-up patients were 30.95%, 57.14% & 19.05%; and for MDR follow-up patients were 11.49%, 21.84% & 19.54% for ZN, AO and culture respectively. The difference in their case detection rates was statistically significant (p < 0.01). No AO negative result with ZN positive samples was found. More number of paucibacillary cases was detected by AO method than ZN. There were 25 cultural contaminated samples. Removing contaminated cultural samples and taking culture as gold standard, the sensitivity and specificity of direct microscopic examination were found to be 60.03% and 98.51% for ZN method; and 83.56% and 94.53% for fluorescent AO method respectively. The percentage of false negative by AO staining was only 16.44% which was in sharp contrast to that of ZN (39.73%). Conclusion: This comparative study proves that AO staining (Fluorescent microscopy) is superior to ZN staining (Light microscopy) in several aspects as efficacy, sensitivity, false negativity. Thus the AO staining aided with culture can prove to be important tool for the effective and reliable diagnosis and screening of pulmonary tuberculosis. Keywords: Mycobacterium tuberculosis, suspected case, follow-up case, MDR, sputum sample
Tuberculosis Research and Treatment
Background. Despite the recent advancement in diagnostic methods, the smear microscopy remains the gold standard for the diagnosis of pulmonary tuberculosis in high burden countries like Ghana. Notwithstanding, fluorescence staining technique provides a more efficient option for the detection of Mycobacterium tuberculosis positive smears. This study therefore aimed at assessing the diagnostic performance of fluorescence microscopy (FM) and Ziehl-Neelsen (ZN) staining techniques in the diagnosis of pulmonary tuberculosis. Methods. A comparative study was carried out on 100 patients who reported at the Out Patients Department (OPD) or the Directly Observed Therapy (DOT) center of the Kade Government Hospital and were suspected of having pulmonary tuberculosis. Two (2) sputum samples each were collected. This included one spot and one morning sample. The smears were prepared and stained with FM and ZN staining techniques. Xpert MTB/RIF assay was also performed. Results. Of the 200 samp...
Comparison between Ziehl Neelsen and Fluorescent Microscopy Techniques of Diagnosing Tuberculosis
Tuberculosis infection particularly pulmonary tuberculosis (PTB) has been spreading at a rampant rate in Kenya. This can be attributed to the high rate of human immunodeficiency virus (HIV) epidemic. The main aim of this study was to compare the effectiveness of Ziehl Neelsen staining technique with fluorescent microscopy for detection of acid fast bacilli in the same sputum samples. The study design is a descriptive cross sectional study and the total number of participants was 27 patients suspected of pulmonary tuberculosis with each submitting 2 sputum samples (total 54). Each sample was stained with Ziehl Neelsen stain and Auramine O staining procedure separately and later examined. Out of 54 samples, 18 (33%) were positive with the fluorescent microscopy and 4 (22%) of them were missed using the conventional Ziehl Neelsen technique. Out of the 4 positive missed, 3 of them were scanty and the other one was 1+. The interator agreement (kappa) was found to be 0.81 indicating that the two methods have a high level of agreement. However, the researcher found the fluorescent microscopy to be more useful in terms of time to read, and accuracy. Thus, it is recommendable to adopt the use of fluorescent microscopy in the diagnosis of pulmonary tuberculosis so as to ensure tuberculosis patients get quality treatment in time.
According to WHO one third of the world population have tuberculosis. The present study was undertaken to compare the efficacy of flurochrome(FI) stain with conventional Z-N stain in the diagnosis of pulmonary & extra-pulmonary tuberculosis. 388 cases of suspected pulmonary tuberculosis were included in the study. All samples were screen for Acid Fast Bacilli (AFB) by Z-N & Fluorescent staining methods. Positive samples detected by fluorescent stain were 57(14.69%) when compared to Zn stain 29(7.47%). Conclusion: Compared to Z-N stain (7.47%) flurochrome staining was found to be more efficient (14.69%) in AFB detection of AFB from cases of Pulmonary Tuberculosis.
Tuberculosis infection particularly pulmonary tuberculosis (PTB) has been spreading at a rampant rate in Kenya. This can be attributed to the high rate of human immunodeficiency virus (HIV) epidemic. The main aim of this study was to compare the effectiveness of Ziehl Neelsen staining technique with fluorescent microscopy for detection of acid fast bacilli in the same sputum samples. The study design is a descriptive cross sectional study and the total number of participants was 27 patients suspected of pulmonary tuberculosis with each submitting 2 sputum samples (total 54). Each sample was stained with Ziehl Neelsen stain and Auramine O staining procedure separately and later examined. Out of 54 samples, 18 (33%) were positive with the fluorescent microscopy and 4 (22%) of them were missed using the conventional Ziehl Neelsen technique. Out of the 4 positive missed, 3 of them were scanty and the other one was 1+. The interator agreement (kappa) was found to be 0.81 indicating that the two methods have a high level of agreement. However, the researcher found the fluorescent microscopy to be more useful in terms of time to read, and accuracy. Thus, it is recommendable to adopt the use of fluorescent microscopy in the diagnosis of pulmonary tuberculosis so as to ensure tuberculosis patients get quality treatment in time.
IP Innovative Publication Pvt. Ltd., 2018
In developing countries, Ziehl-Neelsen (Z-N) sputum smear microscopy is widely used.The present prospective study was undertaken to see the efficacy of Ziehl-Neelson method versus Gabbett and Fluorescent staining in the detection of mycobacteria in sputum sample. 80 sputum samples were collected from suspected tuberculosis patients attending RNTCP OPD at, Nerul, Navi Mumbai. Triplicate smears were prepared from all these samples and stained by the Z-N, Gabbet’s, and Fluorescent stain. Number of smears positive for Acid Fast Bacilli by, Z-N method 13(16%), Gabbett’s method 7(9%), Fluorescent method 26(33%). Combination of two staining methods yielded following results: Z- N + Fluorescent 26 (33%) and Z- N + Gabbett 13(16%). The conclusion from this study is that when smear examination by Z-N is done, there are possibilities of false negative results which can be reduced by using Fluorescent staining. The rate of positivity can be improved by combination of Z-N + Fluorescent staining. So, it may be concluded that combination of ZN and Fluorescent Microscopy may be considered for diagnosis of pulmonary tuberculosis in any diagnostic set up along with culture which is the gold standard. Keywords: Fluorescent, Gabbett’s, Mycobacterium tuberculosis, Revised National Tuberculosis Control Programme (RNTCP), Zehil-Neelson (Z-N).
Abstract Objectives: comparison of results with bright-field and Fluorescence microscopy for detection of acid-fast bacilli (AFB) in sputum. Methodology: Three smears from 200 consecutive sputum specimens between March 2012 and august 2012 were prepared and stained by the Ziehl- Neelsen, Gabbet’s and Fluorescence staining method. Results: The findings showed that the both Z-N, Gabbet’s and Fluorescence staining preparations each showed positive for AFB in 37 (18.5%), 33 (16.5%), 47 (23.5%), respectively. The sensitivities for the Gabbet’s and Fluorescence stain were 89.18% and 94.87% respectively. The positive agreement between Z-N, Gabbet’s (94.28%) and Z-N and Fluorescence stain (97.69%) were good. The Fluorescence microscopy showed higher sensitivity than Z-N staining in detecting AFB in clinical specimens. Smears were read lower magnification than Z-N smear reading (20-40vs 100x), thus smears were read more quickly and efficiently. Fluorescence microscopy has taken less time than Z-N for smear examination. Conclusion: The results obtained with one technique are highly reproducible by the others. Two step Gabbet’s cold staining method was less time consuming and easier to perform in the field. Fluorochrome microscopy appears to be more likely to detect in tuberculosis than bright-field microscopy, and it more than halves the required examination time.
Asian Journal of Pharmaceutical and Clinical Research, 2018
Objectives: The objectives of the study were to find out the presence of Mycobacterium tuberculosis in sputum samples using Ziehl-Neelsen (ZN), Kinyoun’s, and (auramine) fluorescent staining and to compare the three staining techniques with and without Petroff’s concentration and to find out the most preferable staining of M. tuberculosis. Methods: Sputum sample was collected and concentrated by 4% NaOH (Petroff’s concentration). Microscopic examination of the sample was done before concentration and after concentration by ZN staining, Kinyoun’s staining, and fluorescent staining (Auramine). Grading of acid-fast bacilli (AFB) by three staining was done before and after concentration according to RNTCP guidelines.Results: Total of 452 sputum samples were collected and subjected to microscopy examination by ZN, Kinyoun’s, and fluorescent staining methods to compare the presence or absence of AFB with or without concentration. Among the 452 sputum samples, total of 67 (15.6%) sputum s...
Fluorescence microscopy for the diagnosis of smear-negative pulmonary tuberculosis in Ethiopia
African Journal of Laboratory Medicine
Background: Despite its low sensitivity, microscopy remains the main method for the diagnosis of pulmonary tuberculosis in most laboratories in Ethiopia. Few studies have evaluated the performance of light-emitting diode fluorescent microscopy (LED-FM) in bleach-concentrated smear-negative sputum specimens.Objective: This study aimed to evaluate the diagnostic performance of LED-FM for smear-negative pulmonary tuberculosis in Ethiopia.Methods: A total of 194 adult patients with a cough lasting for more than two weeks, and who had three direct smear-negative sputum tests for Mycobacterium tuberculosis by Ziehl-Neelsen light microscopy, were included. All direct Ziehl-Neelsen-stained smear-negative sputum samples were cultured and were also visualised by LED-FM. Smears for LED-FM were performed from bleach-concentrated sputum sediment. The diagnostic performance of the LED-FM was compared to the culture method (the reference standard).Results: Of the 194 smear-negative sputum specimen...
National Journal of Medical Research, 2017
Introduction: For early diagnosis of TB, it is essential to ensure proper identification. Smear microscopy is a simple, economical, less time-consuming technique is a good alternative. The stud was conducted to compare direct smear, concentrated smear and fluroscent microscopy of sputum of patient with tuberculosis; also to assess the sensitivity and specificity of direct and concentrated smear by ZN stain and fluorescent microscopy. Methodology: The 400 samples of suspected to be a case of pulmonary tuberculosis as per RNTCP guidelines are included. Direct smear and concentrated smear were made and stained by Carbolfuchsin methods which include the Ziehl-Neelsen (ZN) and Kenyon methods ( Light /bright field microscope) and Fluorochrome procedure using auramine-O or auramine-rhodamine dyes (Fluorescent microscope -FM). Result: On direct smear, out of 400 samples 138 samples were positive by ZN stain method and 150 samples were positive by FM stain method. While it was 154 samples and 156 sample by respective stains on concentrated smear. The sensitivity of direct and concentrated smear microscopy is comparable to FM stain and Zn stain. The difference between sensitivities (89.61 versus 96.15%.p<.01) obtained by the two methods was significant. The difference between sensitivities (92% versus 98.71%; p<.01) obtained by the two methods was significant. The specificity (100%) was similar for both techniques. Conclusion: The study showed that concentrated AFB microscopy is more efficient to detect M. tuberculosis in respiratory specimens than direct AFB microscopy. Fluorescent microscopy has higher sensitivity and comparable specificity which is further enhanced by concentration.