A study of utility of mantoux test in the suspected cases of tuberculosis at a tertiary health care center

 

Bharat Toshniwal^*, Pankaj Magar^*, Gauri Godbole^**

 

^*Assistant Professor, ^**Professor and HOD, Department of Respiratory Medicine SKNMC and GH Narhe Pune, Maharashtra, INDIA.

Email: bharattosh@gmail.com

 

Abstract              Background: Tuberculosis (TB) in India accounts for the one-fourth of the global cases, adding almost 2.8 million cases annually. Aims: 1) To study the prevalence of tuberculin sensitivity among suspected tuberculosis patients, 2)To study various presentations of TB in Mantoux test positive patients, 3) To restudy the sensitivity and specificity of Mantoux test in tuberculosis in current scenario. Methodology: After approval from the institutional ethical committee this cross-sectional study in the suspected tuberculosis patients attending the OPD at the department of Respiratory medicine of a tertiary health care, SKNMC and GH, Narhe, Pune center during the Six month period i.e. Jan 2017 to June 2017. During Six month period there were 480 patients were referred to the pulmonology department. The analysis was done by MEDCAL Software and the sensitivity, specificity, positive predictive value, negative predictive value etc. was calculated. Result:In our study we have found that Overall induration 311 (64.79%) patients out of that 177 (36.88%) were Positive (≥ 15 mm). So, prevalence of Mantoux test positive was 36.88% in the suspected patients. The majority of the Study participants were in the age group of >50 were122 (25.42%) followed by 21-30 were 98 (20.42 %), 0-10 were 70 (14.58%), 11-20 were 64 (13.33%), 41-50 were 64 (13.33%). The majority of the suspected patients were Male i.e. 262 (54.58%) followed by Female i.e. 218(45.42%). The most common etiology of Mantoux test positive patients was Pulmonary TB was 75 (42.37%) followed by Other were 62 ( 35.03%), followed by Lymph Node TB 24(13.56%), Followed by Pleural effusion were in16( 9.04%). The Sensitivity of the Mantoux test was 95.86% with 95% C.I. (91.65% to 98.32%) and Specificity was 95.18 % (92.17% to 97.28%), Positive Predictive Value was 91.53% , Negative Predictive Value was 97.69%. Conclusion: It can be concluded from our study that the Mantoux test is having very high diagnostic utility as high sensitivity and specificity so employed whenever there is confusion to the diagnosis of tuberculosis but the results below 15 mm should be cautiously interpreted.

Key Words: Tuberculosis (TB), Tuberculin Skin Test (TST), Mantoux test, Sensitivity and specificity of Mantoux test.