Abstract:

Background: Bacteriological confirmation of childhood TB continues to be difficult due to the unavailability of diagnostic facilities, difficulties in obtaining samples, and poor performance of smear microscopy. As a result various peadiatric TB scoring tools were invented in order to help in clinical diagnosis. Therefore this study was done to evaluate various peadiatric tuberculosis score charts for the diagnosis of pulmonary TB against bacteriologically confirmed pulmonary TB in the peadiatric department of Bugando Medical Centre (BMC).

Material and Methods: A cross sectional study was conducted from October 2013 to April 2014 among children suspected to have pulmonary TB at BMC. All children were assessed for TB by using pediatric tuberculosis score charts (Keith Edward, MASA, Fourie and Brazil MOH). Sputum induction was attempted in all patients to obtain sputum which was examined by fluorescent acid fast smear, LJ culture and Xpert MTB/RIF assay. Sensitivity, specificity, positive predictive values and negative predictive value of the score charts against pulmonary TB cases were determined.

Results: A total of 192 patients were enrolled in the study over a period of 5 months. Males formed 53.7% of all the participants. Median (IQR) age was 1.9 (1.2 – 4.4) years. Sputum specimen was obtained in 187 (97.4%) patients, sputum induction was successfully performed in 183 (95.8%) patients. Forty (20.8%) patients were diagnosed with pulmonary TB; among them 10 (5.2%) had confirmed pulmonary TB. Generally, the sensitivity of pediatric TB score charts was poor for diagnosing pulmonary TB (10% - 50%). No baseline characteristics had significant association with confirmed pulmonary TB. Airspace opacification and cavities on chest X-ray had strong association with confirmed PTB with p-value of <0.01 respectively.

Conclusion: Sensitivity and specificity to detect pulmonary TB with pediatric TB score charts evaluated in this study were very low. Induced sputum is possible in our setting therefore bacteriological confirmation of pulmonary TB should be attempted in every child suspected to have TB. CXR components should be incorporated in all TB score to increase the sensitivity.