Sensitivity of direct versus concentrated sputum smear microscopy in HIV-infected patients suspected of having pulmonary tuberculosis
نویسندگان
چکیده
BACKGROUND Sputum concentration increases the sensitivity of smear microscopy for the diagnosis of tuberculosis (TB), but few studies have investigated this method in human immunodeficiency virus (HIV)-infected individuals. METHODS We performed a prospective, blinded evaluation of direct and concentrated Ziehl-Neelsen smear microscopy on a single early-morning sputum sample in HIV-infected patients with > 2 weeks of cough hospitalized in Kampala, Uganda. Direct and concentrated smear results were compared with results of Lowenstein-Jensen culture. RESULTS Of 279 participants, 170 (61%) had culture-confirmed TB. The sensitivity of direct and concentrated smear microscopy was not significantly different (51% vs. 52%, difference 1%, 95% confidence interval (CI): [-7%, 10%], p = 0.88). However, when results of both direct and concentrated smears were considered together, sensitivity was significantly increased compared with either method alone (64%, 95% CI: [56%, 72%], p < 0.01 for both comparisons) and was similar to that of direct smear results from consecutive (spot and early-morning) specimens (64% vs. 63%, difference 1%, 95% CI: [-6%, 8%], p = 0.85). Among 109 patients with negative cultures, one had a positive direct smear and 12 had positive concentrated smears (specificity 99% vs. 89%, difference 10%, 95% CI: [2%, 18%], p = 0.003). Of these 13 patients, 5 (38%) had improved on TB therapy after two months. CONCLUSION Sputum concentration did not increase the sensitivity of light microscopy for TB diagnosis in this HIV-infected population. Given the resource requirements for sputum concentration, additional studies using maximal blinding, high-quality direct microscopy, and a rigorous gold standard should be conducted before universally recommending this technique.
منابع مشابه
Author's response to reviews Title: Sensitivity of direct versus concentrated sputum smear microscopy in HIV-infected patients suspected of having pulmonary tuberculosis Authors:
متن کامل
مقایسه ارزش تشخیصی اسمیر خلط به دو روش میکروسکوپی در بیماران مشکوک به سل ریوی با و بدون استفاده ازهیپوکلریت سدیم
Background and purpose: Direct smear microscopy is the most common method of detecting tuberculosis with 70% sensitivity in best conditions, therefore, researches have always focused on improving the sensitivity of sputum smear. This study aimed at comparing the diagnostic value of sputum smear using light microscopy and fluorescence microscopy without sodium hypochlorite in patients with suspe...
متن کاملComparison of Flurochrome , Ziehl-Neelsen and Tan Thiam Hok Staining Methods for Detection of Mycobacterium tuberculosis in Sputums of Patients with Pulmonary Tuberculosis
Abstract Background and objectives: Direct smear microscopy, because of its simplicity, rapidity, low cost and relatively sensitive is a suitable method to detecting pulmonary tuberculosis. This experiment was aimed at determining the best method for detecting Mycobacterium tuberculosis among three kinds of staining methods: Fluorochrome, Ziehl Neelsen and Tan Thiam Hok . Material and Methods: ...
متن کاملDetection of Mycobacterium tuberculosis from the stool of HIV sero-positive individuals suspected of pulmonary tuberculosis
BACKGROUND The impact of tuberculosis (TB) is exacerbated in Africa because of the human immunodeficiency virus (HIV) pandemic. Pulmonary tuberculosis (PTB) diagnosis is difficult in HIV-infected patients and negative sputum results are more common which leads to diagnostic delay and increases morbidity and mortality. Extra-pulmonary samples such as stool may be easier to obtain and our approac...
متن کاملComparison of sensitivity and specificity of PCR and sputum smear compared to culture in diagnosis of tuberculosis
Background: Molecular detection has recently been proposed by nucleic acid amplification, known as polymerase chain reaction (PCR). The aim of this study was to compare the diagnostic method of smear and polymerase chain reaction with culture in terms of sensitivity, specificity, positive and negative predictive value in the diagnosis of pulmonary tuberculosis. Methods: In this cross-sectional...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 9 شماره
صفحات -
تاریخ انتشار 2009