Optimizing Tuberculosis Diagnosis: A Proposed Same-Day Strategy for Spot-Morning-Spot Smear Microscopy in Low Resource Settings

Abstract

Spot-morning-spot (SMS) smear microscopy has long been the conventional method for tuberculosis (TB) diagnosis, but its requirement for multiple visits to health facilities poses inconvenience for patients. This book chapter presents a comprehensive study that aims to investigate the sensitivity, specificity, and predictive values of a "proposed same-day" strategy for one-day TB diagnosis, as compared to the standard SMS method, with culture as the reference standard. The study was conducted on a total of 180 TB-suspected patients. The proposed same-day method involved the collection of an additional sputum sample at least one hour after the first sample, in addition to the standard SMS samples. Both samples underwent culture testing, and data analysis was performed using Open Epi data and Mc Nemar’s tests for comparison.

The sensitivity of the conventional SMS method was 81.8% (95% CI: 65.6-91.4), while the proposed same-day method exhibited a sensitivity of 75.8% (95% CI: 58.9-87.2) with Ziehl-Neelsen (ZN) staining (P-value = 0.298). Furthermore, both methods demonstrated identical specificity at 100% (97.1-100) with a P-value of 1.00. Similarly, for light-emitting diode fluorescence microscopy (LED-FM), the sensitivity was 84.9% (69.1-93.4) and 81.8% (65.6-91.4) in the conventional and proposed methods, respectively, with no significant difference in sensitivity (P-value = 0.568). The specificity for LED-FM was also comparable between the two methods, with a P-value of 0.155.

The findings suggest that with extensive and comprehensive training for laboratory technicians and technologists, it is feasible to diagnose pulmonary tuberculosis (PTB) in one day using the proposed same-day strategy.