A comparative Study of Tuberculin Skin Test with Fluorescent, Ziehl-Neelsen Staining and Culture for the Diagnosis of Pediatric Tuberculosis in Khartoum State

Abstract

Tuberculosis is one of the leading causes of mortality from an infectious disease world-wide. Current estimates indicate that more than two million people die from this disease each year. This study was carried out in Khartoum state during the period between May and December 2011. The main objective was to compare Tuberculin skin test with fluorescent, Ziehl-Neelsen (ZN) staining and culture for the diagnosis of pediatric tuberculosis. 197 samples of gastric lavage and sputum were collected from different TB centers in Khartoum State including Academic Charity Hospital, Soba University Hospital and Elshab Teaching Hospital. Tuberculin Skin Test was done for every patient, Then ZN and Auramin O (AO) staining smear and culture were performed. The study showed that only 41.9% of Tuberculin Skin Test (TST) positive children were found to be positive with other laboratory tests (ZN, Ao stain and culture). This study concluded that TST is highly sensitive in detection of TB infection, but low specific in comparison with ZN, Auramin O and culture (gold standard for diagnosis of TB infection). The study results indicate that factors other than tuberculosis, such as NTM infection or previous BCG-vaccination, are widely contributing to positive TST results among children in Sudan.