Comparison Between Blood Polymerase Chain Reaction (Pcr) And The Scoring System In The Diagnosis Of Pulmonary Tuberculosis In Sudanese Children

A prospective hospital based study was carried out during the period from July to September to evaluate the blood Polymerase Chain Reaction (PCR) in the diagnosis of pulmonary tuberculosis in children. 101 children in the age group 0-14 years attending to the T.B clinic in Gaafar Ibn Auf Hospital, Mohammed Elamin Hospital and Ahmed Gasim Hospital for children were included in this study. A questionnaire including information about symptoms, investigations done and final diagnosis was completed. A venous blood sample was taken for PCR. Results showed that 56.4% of children were males and that 78.2% of them were belonging to a low socioeconomic class. Cough was the main complaint in 98%; fever was reported in 90% and weight loss in 85.1%. History of contact with an adult with T.B or chronic cough was obtained in 59.4%. BCG vaccination was reported in 92.1% of children studied. Chest x-ray was done for 94.1% of children and showed suggestive findings in 85% of them. Sputum examination were performed in 37.4% of children, of whom 28.5% showed positive results. The ESR was done for all children and 84% of them showed raised ESR. The mantoux test was done for 92% of children and 60.3% of them were positive. iv 91.1% of children scored > 5 by scoring system denoting positive results. The blood PCR was done for all children and only 40.6% showed positive results. On comparing the results of the PCR with the scoring system, the sensitivity of blood PCR was calculated to be 42.4%, specificity 77.7%, positive predictive value 95.1 and negative predictive value 11.6%. Blood PCR showed significant association with raised ESR, but no significant association was noted with chest x-ray finding, mantoux tests or sputum examination. We recommend that blood PCR can be used with other methods to diagnose pulmonary T.B in difficult cases