Changes in tuberculosis notifications and treatment delay in Zambia when introducing a digital X-ray service

SETTING: In August 2009, a digital chest X-ray (CXR) machine was installed at a busy urban health centre in Lusaka, Zambia.OBJECTIVE: To describe the changes in tuberculosis (TB) notifications and treatment delay ≥7 days in Zambia after introducing a digital X-ray service.DESIGN: Operational retrospective research of TB notification, laboratory and CXR data for Q4 2008 (prior to digital CXR) compared to Q4 2009.RESULTS: Notifications for sputum smear-negative TB increased by 8.1%, from 370/527 (70.2%) in Q4 2008 to 425/544 (78.1%) in Q4 2009, despite a 6.7% decrease in sputum smear positivity in Q4 2009. TB treatment delay decreased from 75/412 (18.2%) in Q4 2008 to 52/394 (13.2%) in Q4 2009 ( P = 0.05).CONCLUSION: In Q4 2009, sputum smear-negative TB notifications increased and treatment delay decreased. However, accurate diagnosis of TB is challenging in this setting, and misdiagnosis and overtreatment may occur. Moreover, other factors in addition to the introduction of the digital X-ray service could have contributed to these findings. Nonetheless, we found that the digital X-ray service had many advantages and that it may aid in more efficient TB diagnosis.