Training laboratory technicians from the Ethiopian periphery in the MODS technique enables rapid and low-cost diagnosis of Mycobacterium tuberculosis infection

Tuberculosis (TB) is a leading cause of morbidity and mortality and is frequently complicated by emergence of drug-resistant strains. Diagnosis of TB in developing countries is often based on the relatively insensitive acid-fast staining that does not enable susceptibility profiling. Microscopic observation drug susceptibility assay (MODS) is an inexpensive, simple method that enables rapid TB culture coupled with susceptibility testing. A 3-week MODS training of three Ethiopian laboratory technicians was conducted at Hadassah-Hebrew University Medical Center, Israel. Results of the trainee readings were blindly assessed by an experienced instructor. Two hundred fifty-five (255) trainee culture readings were evaluated throughout the course. The sensitivity and specificity were 75-100% and 31.5-100%, respectively. Multivariate analysis revealed that sensitivity and duration of incubation were positively correlated, although specificity was positively correlated with the length of training. MODS can be reliably performed by laboratory technicians inexperienced in culture techniques in developing countries, with high sensitivity and specificity reached after a brief learning period.