Comparison of Sputum Smear Microscopy and Rapid Tuberculosisantibody Detection Test Kits for Diagnosis of Pulmonary Tuberculosis in Abia State, Nigeria

摘要

The SSM （sputum smear microscopy） and five immunochromatographic tuberculosis antibody detection tests （DiaSpot TB, Spodex TB, SD Rapid TB, Clinotech TB Screen and Precious One-step TB） were compared for diagnosis of active TB at the Leprosy and Tuberculosis Referral Hospital, Uzuakoli, Abia State, Nigeria. Sputum specimens from 150 study participants （male/female ratio, 0.81） were cultured on Lowenstein-Jensen slopes and direct smears were stained by Ziehl-Neelsen technique and examined by light microscopy. Sera were tested for anti-TB antibodies using the rapid TB tests. A total of 91 participants were culture positive, 79 （86.8%） for M. tuberculosis and 12 （13.2%） for nontuberculous mycobacteria. The sensitivity of SSM was 50% （95% CI： 39.0-61.0） and specificity was 92.3% （95% CI： 86.4-98.2） in those culture positive for M. tuberculosis. The sensitivity and specificity of the Rapid TB tests ranged from 24.1-39.2% and 78.4-87.8%, respectively. None of the five rapid TB tests had acceptable level of accuracy for diagnosis of active TB. The sensitivity of SSM though moderate is inadequate for long term TB control in this setting.