ABSTRACT
BACKGROUND: Light-emitting diode fluorescence microscopy (LED-FM) has been shown to be more sensitive than conventional bright field microscopy using Ziehl-Neelsen (ZN) stain in detecting sputum smear positive tuberculosis in controlled laboratory conditions. In 2012, Auramine O staining based LED-FM replaced conventional ZN microscopy in 200 designated microscopy centres (DMC) of medical colleges operating in collaboration with India's Revised National Tuberculosis Control Programme. We aimed to assess the impact of introduction of LED-FM services on sputum smear positive case detection under program conditions. METHODS: This was a before and after comparison study. In 15 randomly selected medical college DMCs, all presumptive TB patients who underwent sputum smear examination in the years 2011 (before LED-FM) and 2012 (after LED-FM) were compared. An additional 15 comparable DMCs that implemented conventional ZN sputum smear microscopy were also selected for comparison between 2011 and 2012. RESULTS: The proportion of presumptive TB patients (PTP)found sputum smear positive increased by 30%- from 13.6% (3432/25159) in 2011 to 17.8% (4706/26426) in 2012 (P value <0.01) in the sites that implemented LED-FM microscopy, whereas in DMCs where the ZN staining procedure is followed the proportion of sputum smear positive had remained unchanged (13.0%versus 12.6%;P value0.31). CONCLUSION: Use of LED-FM significantly increased the proportion of smear positive cases among presumptive TB patients under routine program conditions in high workload laboratories. The study provides operational evidence needed to scale-up the use of LED-FM in similar settings in India and beyond.
Subject(s)
Microscopy, Fluorescence/methods , Tuberculosis, Pulmonary/diagnosis , Adolescent , Adult , Aged , Child , Child, Preschool , Humans , India , Infant , Infant, Newborn , Middle Aged , Sputum/microbiology , Young AdultABSTRACT
In July 2012, light-emitting diode fluorescence microscopy (LED-FM) replaced conventional light microscopy using Ziehl-Neelsen stain in the detection of sputum-positive pulmonary tuberculosis in 190 microscopy centres of medical colleges operating under India's Revised National Tuberculosis Control Programme. We compared the performance of LED-FM (July-December 2012) to that of conventional microscopy (July-December 2011) across 190 sites. Of 222 658 patients examined using conventional microscopy, 28 042 (12.6%) were smear-positive, while of 224 714 examined using LED-FM, 33 552 (14.9%) were smear-positive, an additional yield of 5251 cases after adjusting for the increase in patients examined. We recommend replacing conventional microscopy with LED-FM in high workload microscopy centres in India.
Dans 190 centres de microscopie des collèges médicaux travaillant dans le Programme Révisé de Lutte contre la Tuberculose en Inde, l'examen microscopique par fluorescence à diode émettrice de lumière (LED-FM) a remplacé l'examen microscopique à lumière conventionnelle utilisant la coloration de Ziehl-Neelsen pour la détection de la tuberculose pulmonaire à frottis positif. Nous avons comparé les performances du LED-FM entre juillet et décembre 2012 à celles de l'examen microscopique conventionnel (juilletdécembre 2011) dans l'ensemble des 190 sites. Les frottis ont été positifs chez 28 042 (12.6%) des 222 658 patients examinés par microscopie conventionnelle comparé à 33 552 (14.9%) des 224 714 patients examinés par LED-FM, un rendement supplémentaire de 5251 cas après ajustement pour l'augmentation du nombre de patients examinés. Nous recommandons le remplacement de l'examen microscopique conventionnel par le LED-FM en Inde dans les centres de microscopie dont la charge de travail est élevée.
En julio del 2012 la microscopia de fluorescencia con diodos electroluminescentes (LED-FM) reemplazó el sistema tradicional de microscopia de luz con tinción de Ziehl-Neelsen en la detección de casos de tuberculosis pulmonar con baciloscopia positiva en 190 centros de microscopia de las facultadas de medicina que funcionan en conformidad con el Programa Nacional Revisado de Control de la Tuberculosis de la India. En el presente artículo se comparó el rendimiento diagnóstico de este nuevo sistema de microscopia (entre julio y diciembre del 2012) con el rendimiento de la microscopia de luz (entre julio y diciembre del 2011) en 190 centros. De los 222 658 pacientes investigados mediante la microscopia de luz, 28 042 (12,6 %) presentaron baciloscopia positiva. De los 224 714 pacientes cuyas muestras se examinaron mediante la LED-FM, 33 552 (14,9 %) obtuvieron una baciloscopia positiva, lo cual corresponde a un incremento del rendimiento de 5251 casos, después de corregir con respecto al aumento del número de pacientes examinados. Se recomienda sustituir el sistema tradicional de microscopia de luz por la LED-FM en los centros con un alto volumen de trabajo en la India.
