Radiological presentation of pulmonary tuberculosis infected by the W-Beijing Mycobacterium tuberculosis strain.

SETTING

The W-Beijing strain of Mycobacterium tuberculosis is distributed globally, and is associated with high drug resistance rates in some areas. The effect of the W-Beijing strain on radiological features of pulmonary tuberculosis (PTB) remains unclear.

OBJECTIVE

To compare the chest radiological presentation of PTB in patients infected with W-Beijing with that of patients infected with non-W-Beijing strains, and to explore factors affecting radiological patterns.

DESIGN

Culture-proven PTB patients without previous anti-tuberculosis treatment were enrolled retrospectively. Chest radiographs were independently reviewed by two qualified chest physicians, and radiological presentation was classified into characteristic and unusual patterns.

RESULTS

Of 233 patients studied, 123 (52.8%) were infected with the W-Beijing strain. Characteristic radiological patterns (91.1% vs. 76.4%, P = 0.002) and fibronodular lesions without cavity (57.7% vs. 43.6%, P = 0.032) were more common, while miliary lesions (0.0% vs. 3.8%, P = 0.048) were less frequent, in the W-Beijing group. After stepwise logistic regression analysis, the W-Beijing strain (P = 0.006) was found to be an independent factor for the characteristic radiological pattern for PTB.

CONCLUSION

The characteristic radiological pattern for PTB was more common in patients infected with the W-Beijing strain. M. tuberculosis genotyping was an independent factor affecting the radiological presentation of pulmonary TB.