Performance and acceptability of the FluoLED Easy (TM) module for tuberculosis fluorescence microscopy

Abstract

SETTING: Tuberculosis (TB) reference laboratory in Bangkok, Thailand, and two health centres in Dar es Salaam, Tanzania. OBJECTIVES: To assess the performance and user-friendliness of a light-emitting diode (LED) module (FluoLED Easy) for TB fluorescence microscopy (FM). DESIGN: Equivalence study vs. conventional FM in Bangkok using blinded re-reading; routine detection in the health centres in Dar es Salaam compared to Ziehl-Neelsen (ZN) over 2 years, with rechecking of FM smears. RESULTS: For 461 smears re-read, 99.1% concordance with conventional FM was obtained. FluoLED introduction caused a lasting increase in detection in the routine of each of the health centres by on average 20%. Blinded rechecking failed due to unreliable registration. Onsite rechecking of a convenience sample showed absence of false-positive results in one centre and confusion with artefacts that could have been avoided by more training in the other. LED FM was highly appreciated, with both laboratories refusing to revert to ZN as originally intended. CONCLUSIONS: A simple microscope with a FluoLED module can yield results equivalent to those of conventional FM. Low cost, technical appropriateness and excellent acceptance justify its use in low-income settings, contrary to classical systems. LED FM can lead to increased sensitivity, but for optimal yield good training and quality assurance remain essential requirements.