Application of modern microbiological diagnostic methods for tuberculosis in Macha, Zambia

作者:Verweij K E*; Kamerik A R; van Ingen J; van Dijk J H; Sikwangala P; Thuma P; Nouwen J L; van Soolingen D
来源:International Journal of Tuberculosis and Lung Disease, 2010, 14(9): 1127-1131.

摘要

SETTING: Macha, Zambia.
OBJECTIVE: To assess the benefits of auramine-O staining fluorescence microscopy and Mycobacterial Growth Indicator Tube (MGIT) liquid culture with molecular identification in tuberculosis (TB) diagnostics.
DESIGN: One hundred patients suspected of TB were subjected to three sputum sample examinations applying Ziehl-Neelsen (ZN) and auramine-O staining and MGIT culture. Positive cultures were identified using the Geno-Type(R) CM assay; cultures identified as Mycobacterium tuberculosis complex were the gold standard for a diagnosis of TB.
RESULTS: The 100 patients produced 271 sputum samples; of these, 30 patients had positive cultures. M. tuberculosis complex bacilli were isolated in 17 (56.7%) patients, non-tuberculous mycobacteria (NTM) in 11 (36.7%) and other acid-fast bacilli in two. Forty-eight samples (17.7%) were contaminated. Auramine-O detected 16 (57.1%) patients culture-positive for mycobacteria and 12 patients with culture-proven TB, vs. respectively 8 (28.6%, P = 0.008) and 7 (41.2%, P = 0.044) for ZN. Three of eight auramine-positive/ZN-negative patients were culture-positive for NTM only.
CONCLUSION: The auramine-O method significantly increases sensitivity, although the higher NTM detection rate implies that this does not in itself lead to a more accurate diagnosis of TB. MGIT culture is highly sensitive, although contamination rates were a drawback; the high frequency of NTM isolation warrants a robust identification method.

  • 出版日期2010-9