Comparison of Modified Fluorescent Method and Conventional Ziehl Neelsen Method in The Detection of Acid Fast Bacilli in Lymph Node Aspirates.

Umasankar, T (2012) Comparison of Modified Fluorescent Method and Conventional Ziehl Neelsen Method in The Detection of Acid Fast Bacilli in Lymph Node Aspirates. Masters thesis, Stanley Medical College, Chennai.


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Pulmonary Tuberculosis (TB) Is A Contagious Bacterial Infection That Involves The Lungs, But May Spread To Other Organs. The Great Pioneer Of Bacteriology, Robert Koch, Discovered A Bacterium Which He Called Bacillus Tuberculosis And Is Now Known As Mycobacterium Tuberculosis, Is The Etiological Agent Of Tuberculosis[1]. Tuberculosis Continues To Be A Major Health Problem In Developing Countries Due To Poor Sanitation, Overcrowding And Lack Of Knowledge About The Disease. AIDS Patients Show Coinfection With Mycobacterium Tuberculosis. More Than 50% Of Tuberculosis Cases Are From Asia And Africa Alone. It Has Been Estimated That One Patient Die Every Minute Due To MTB In India. Symptoms Of Pulmonary TB Include Cough , Coughing Up Blood(Hemoptysis), Excessive Sweating Especially At Nights, Fatigue, Evening Rise Of Temperature, Unexplained Weight Loss. Other Symptoms That May Occur With This Disease Are Dyspnea, Chest Pain, Wheezing., Clubbing Of The Fingers Or Toes (In People With Advanced Disease), Enlarged Or Tender Lymph Nodes In The Neck Or Other Areas, Pleural Effusion, Unusual Breath Sounds (Crackles)[2,3]. TB Is A Preventable And Potentially Curable Disease Provided It Is Detected Earlier In The Course Of The Disease. Microscopy Is The Most Common Case Detection Test In Use. Microscopy Is Inexpensive, Relatively Rapid To Perform, And, In Countries Where Tuberculosis Is Endemic, Is Highly Specific. The Average Sensitivity Of Sputum Microscopy For Pulmonary Tuberculosis In Immunocompetent Individuals Is Less Than 60% Compared With Culture, Even In Research Settings[5]. Microscopy Can Also Be Done In Other Pathological Materials Like Lymph Node Aspirates And Body Fluids Including CSF. The Diagnostic Value Of FNAC Of Lymphnodes In Tuberculous Lymphadenitis Has Been Emphasized By Several Workers[6,7,8]. FNAC Examination Is Simple, And A Relatively Painless And Less Cumbersome Procedure Introduced First By Martin[9], Can Be Adopted In Lieu Of Biopsy. This Can Be Carried Out As An O.P.Procedure And Preparation Of The Smears Can Be Carried Out In The Laboratories Even At The Peripheral Hospitals. This Will Serve As An Effective Adjuvant In Arriving At An Appropriate Diagnosis. Identification Of AFB In Lymph Node Aspirates By The Routine H&E Stain Is Difficult. We Give A Diagnosis Of Granulomatous Lesion Based On The Presence Of Epitheloid Cell,Giant Cells And Caseous Necrosis.As The Etiology Of Granulomatous Lesions Are Varied We Need To Arrive At A Definitive Diagnosis For The Cause Of The Granulomatous Lesions MTB Is The Commonest Cause Of Granulomatous Lesion In Our Country.In Order To Give A Definitive Cytological Report That The Cause Of Granulomatous Lesion Is Due To MTB,We Have To Employ Special Stains Like Ziehl Neelsen .Ziehl Neelsen Method Is The Current Gold Standard Test Employed For The Identification Of AFB On FNAC Smears. But The Sensitivity Is Low .MTB Culture Though Sensitive And Specific Takes A Longer Time For The Growth Of The Organism. The Tests Based On PCR Have Shown Promise For The Detection Of Mycobacteria In Clinical Samples[15]. However, Several Different PCR Systems That Have Been Described For The Diagnosis Of Tuberculosis Have Produced Widely Differing Results With Regard To The Sensitivity Of The Assay With Different Types Of Clinical Samples .PCR Although A Sensitive Test Detects Both Viable And Non Viable Bacilli[16]. Peripheral Blood Appears To Be The Clinical Material Of Choice For PCR, Especially In Cases Of Disseminated And Extrapulmonary Forms Of The Disease[17]. Hence We Need A Test Which Should Be Sensitve, Rapid, Easy To Perform And Cost Effective As Well. Auramine O Has Been Used In Fluorescence Acid-Fast Microscopy Since It Was First Introduced By Hageman In 1938 And Reported By Richards Et Al[11]. This Method Is Said To Be More Sensitve Than The Ziehl Neelsen Method And Can Be Performed On Lymph Node Aspirates As Well. In This Study The Sensitivity, Specificity, Efficacy And Other Advantages Of Using AO Stain Over The Conventional Gold Standard Ziehl Neelson Stain In Granulomatous Lesions Of Lymph Node Are Compared And The Results Analysed.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Fluorescent Method ; Conventional Ziehl Neelsen Method ; Detection Acid ; Fast Bacilli ; Lymph Node Aspirates.
Subjects: MEDICAL > Pathology
Depositing User: Subramani R
Date Deposited: 27 Jun 2017 11:38
Last Modified: 27 Jun 2017 11:38

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