Evaluation of Quantiferon TB Gold Test for the Diagnosis of Latent and Active Tuberculosis

Milind S Panchbhai,Hatim F Daginalwala,Rajpal S Kashyap,V S Agrawal,Hemant J Purohit,Girdhar M Taori

doi:10.5539/ijb.v3n1p122

Milind S Panchbhai, Hatim F Daginalwala + Show 4 more

Open Access

https://doi.org/10.5539/ijb.v3n1p122

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Abstract

Background: Tuberculosis (TB) is a worldwide public health problem. The present study evaluate usefulness of Quantiferon TB Gold (QFT-G) test along with tuberculin skin test (TST) in the diagnosis of TB and to demonstrate the prevalence of latent TB in the study population of high TB prevalence area of Nagpur, India.Materials and methods: Venous blood sample of 74 study population were collected and QFT-G and TST tests were performed in collected blood samples.Results: QFT-G was more positive than TST in diagnosing TB infection. The overall specificity of QFT-G & TST was 50% & 64.86% respectively along with 50% discordant results between QFT-G and TST. Conclusion: Diagnosis of different tuberculosis along with latent is better by QFT-G as compare to TST except suspected pulmonary TB infection. However, the detection and prevalence (56%) of latent TB infection is much greater when both the tests are combined. Key words: QFT, TST, latent tuberculosis, ESAT-6, CFP-10

Highlights

Tuberculosis is a major health problem in India due to the presence of latent tuberculosis infection and inadequacy in diagnosis of tuberculosis (Manabe Y.C 2000). 22 % of the tuberculosis in the world population has been reported from India
The objective of the present study is to evaluate usefulness of Quantiferon TB Gold test along with TST in the diagnosis of different types of tuberculosis infection and to demonstrate the prevalence of latent tuberculosis in the unscreened healthy population in high tuberculosis prevalence area of Nagpur
On the basis of diagnostic criteria for different tuberculosis group we found that out of the 74 individuals, 12 (16%) were of confirmed active tuberculosis, 8 (11%) were of suspected pulmonary tuberculosis, 6 (8%) cases of old pulmonary tuberculosis, 2 (3%) cases of confirmed extra pulmonary tuberculosis, 12 (16%) were of suspected extra pulmonary tuberculosis and 34 (46%) cases of healthy and disease control group (Table 2)

Summary

Introduction

Tuberculosis is a major health problem in India due to the presence of latent tuberculosis infection and inadequacy in diagnosis of tuberculosis (Manabe Y.C 2000). 22 % of the tuberculosis in the world population has been reported from India. Tuberculosis is a major health problem in India due to the presence of latent tuberculosis infection and inadequacy in diagnosis of tuberculosis (Manabe Y.C 2000). Recent health report shows that incident rate for the tuberculosis in India is very high (168/100000) while prevalence rate is 283/100000 (Global tuberculosis control-WHO report 2002, 2008). Acid Fast Bacterium staining and culture are most widely used methods for the diagnosis of the active tuberculosis infection (Global tuberculosis control-WHO report 2009, Perkins M.D 2000). According to recent WHO report smear microscopy is insensitive and it detects roughly 50% of all the active cases of TB (Global tuberculosis control-WHO report 2002). On the other hand latent tuberculous infection (LTBI) is diagnosed on the basis of tuberculin skin test (TST). Quantiferon TB Gold test require

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