​Interpretation And Clinical Correlation Of Tuberculin Skin Test Results Among Clinically Diagnosed Childhood Tuberculosis

ABSTRACT

Background: Diagnosing tuberculosis (TB) was still a worldwide big challenge in cases with negative reports of Xpert MTB/RIF, smear, and culture test of acid-fast bacilli (AFB). A single, direct Xpert MTB/RIF test identified 98.2% of the sputum smearpositive TB cases and 72.5% of those with sputum smear-negative TB. Such a diagnosis was often made based on the clinicalcriteria and other supportive findings like tuberculin skin test (TST).Objective: Hence, this study was to help in the diagnosis and treatment of clinically diagnosed childhood TB, especially in thelimited resource rural areas and developing countries.Materials and Methods: Based on the WHO revised criteria of TB diagnosis, to include clinically diagnosed TB instead ofsmear-negative TB disease, an operational definition of clinically diagnosed TB for the selection of participants for TST wasestablished for this study. Based on the recommendation of the CDC team at the Saskatchewan Lung Association, 2007-03-21at the Wayback Machine, the TST results of the study were interpreted.Results: Hence, in our study, the sensitivity of TST was 82.35% (≥10 mm) in the age group of 1–4 years and 60.16% (≥15 mm)in the age group of >4–12 years. However, this study shows that the positivity rate of TST was increased from 60.16% (≥15 mm)to 86.15% (≥10 mm), if the TST results≥10 mm were interpreted as positive even in this age group of >4 years–12 years.Conclusion: In such very difficult situations of clinically diagnosed TB, this study observed that empiric anti-TB treatment may bestarted without microbiological confirmation to clinically diagnosed childhood TB patient with negative reports of Xpert MTB/RIF,smear, and culture test of AFB, presented with one or more of the following symptoms and signs of clinically diagnosed childhoodTB (1) Chronic anorexia, (2) ill health and fatigue, (3) weight loss of >5% during the past 3 months or documented failure to striveduring the preceding 3 months, (4) night sweating and persistent fever >2 weeks, and (5) non-remitting cough >2 weeks but cannot bediagnosed clinically by any possible causes than TB, and positive TST report, in resource-limited rural areas anddeveloping countries.