Comparison of the modified fluorescent method and conventional Ziehl–Neelsen method in the detection of acidfast bacilli in lymphnode aspirates

Abstract

Objectives:The objectives were to correlate the modified fluorescent method with the conventional Ziehl–Neelsen (ZN) method for the detection of acid-fast bacilli (AFB) and, also to study the efficacy and advantages of using the auramine–rhodamine stain on lymph node aspirates under fluorescent microscopy.Methods:In 108 consecutive patients with a clinical suspicion of tuberculosis (TB) presenting with lymphadenopathy, fine needle aspirations were performed. Smears from the aspirates were processed for routine cytology, the conventional ZN method, and the modified fluorescent method. The significance of the modified fluorescent method over the conventional ZN method was analyzed using the chi-square test.Results:Out of 108 aspirates, 102 were studied and remaining 6 were excluded from the study due to diagnosis of malignancy in 4.04% (4/6) and inadequate aspiration in 2.02% (2/6). Among the 102 aspirates, 44.11% (45/102) were positive for AFB on the conventional ZN method, 58.9% (60/102) were indicative of TB on cytology, while the smear positive increased to 81.37% (83/102) on the modified fluorescent method.Conclusions:Fluorescent microscopy has the advantage of speed and ease of screening, and reduces observer fatigue. The modified fluorescent method was found to be more advantageous than routine cytology and conventional ZN method, particularly in paucibacillary cases. The bacillary positivity rates were higher in the modified fluorescent method than in the ZN method. Hence, the modified fluorescent method can be an adjuvant when used with routine cytology for the identification of AFB.

Comparison of Z. N. staining & fluorescent microscopy in detection of M. Tuberculosis bacilli in Fine needle aspiration smears

“…In present study maximum cases affected were in the age group of 21-30 yrs, which accounted for 56.92% (37/65) of total cases. The age group most commonly affected by tuberculosis in our study is correlated with other studies like Dagar et al [14] Annam et al [15]. In our study mean age was 28.5 years, Dagaret al [14] has also observed the similar mean age for diagnosis.…”

“…Shows cytological criteria for the diagnosis of tubercular lymphadenitis [4]. Conventional Ziehl-Neelsen (ZN) method for acidfast bacilli (AFB) plays a key role in the diagnosis and the monitoring of treatment in tuberculosis [5]. Fluorescent microscopy using auramine-rhodamine (AR) staining is rapid, simple, easy method with high detection rate for AFB as compared to ZN method [6,7].…”

Correlation of Various Techniques in Diagnosis of Tuberculous Lymphadenitis on Fine Needle Aspiration Cytology

“…Culture is essential for a definitive diagnosis; however, it takes weeks for identification, and its sensitivity is also relatively low in paucibacillary conditions [5, 6]. Conventional Ziehl-Neelsen (ZN) method for acid-fast bacilli (AFB) plays a key role in the diagnosis and the monitoring of treatment in tuberculosis [7]. Its major disadvantages are low sensitivity, time consuming, and oil immersion use.…”

Conventional and Recent Diagnostic Aids in Tuberculous Lymphadenitis: A Brief Overview

“…Ziehl-Nelson (ZN) staining -ZN staining is an essential diagnostic tool for the identification of AFB and the evaluation of treatment outcome in TB [16]. Bright red rods against blue, green or yellow background are characteristic of AFB [3] (Fig.…”