Back to Annual Meeting

Back to Annual Meeting

APHA Scientific Session and Event Listing

Recorded presentation

Maria-Graciela Hollm-Delgado, MSc¹, Luz Caviedes, BSc², Robert Gilman, MD, DTM&H³, Jorge Coronel, BSc², Aldo Vivar, MD⁴, Eduardo Sanchez, MD⁵, Yvette Piñedo, MD⁴, Jon S. Friedland, MD⁶, and David A. J. Moore, MD, MSc⁶. (1) Département de Médecine Sociale et Préventive, Université de Montréal, CP 6128 Succ. Centre-Ville, Montreal, QC H3C 3J7, Canada, (514)695-0876, maria-graciela.hollm-delgado@umontreal.ca, (2) Laboratorio de Investigación de Enfermedades Infecciosas, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, San Martin de Porras, Lima, Peru, (3) Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St. Rm W5515, Baltimore, MD 21205, (4) Hospital Nacional General Arzobispo Loayza, Av. Alfonso Ugarte 848, Lima, Peru, (5) Hospital Nacional Hipólito Unanue, Av. Cesar Vallejo 1390, El Agustino, Peru, (6) Wellcome Centre for Clinical Tropical Medicine, Imperial College London, DuCane Road, London, W12 0NN, United Kingdom

Diagnosing tuberculosis (TB) in developing countries continues to be a major public health challenge, largely due to high costs, delays in processing samples, and the need for complex laboratory facilities. Recently, the Microscopic Observation Drug Susceptibility Assay (MODS) was shown to overcome these barriers, detecting TB faster and more efficiently than gold-standard rapid techniques yet at one-tenth the cost. In this study, we evaluate for the first time its clinical utility among HIV-infected patients. We prospectively screened 156 hospitalized in-patients for pulmonary TB at two public hospitals in Lima, Peru, using clinical, bacteriological, and radiographic measures. Sputum and/or gastric aspirate samples were collected and cultured in parallel using Lowenstein-Jensen, MBBacT, and MODS. Clinical validity was estimated using marginal logistic regression to account for multiple samples per patient. We found that of 28 patients identified with culture-positive TB, 61% were smear-negative and 29% had normal chest radiographs. Using sputum smear microscopy and chest radiography alone, the only tools routinely available in developing world settings, 25% of patients with culture-positive TB would have been overlooked. MODS detected 98% [95% CI: 86 – 100] of all HIV-positive patients with TB, and correctly identified 100% [95% CI: 100 – 100] of all culture-negative patients. Sensitivity of MODS remained high for patients with CD4 counts less than 200 cells/uL [98%; 95% CI: 86 - 100], those who were smear-negative [96%; 95% CI: 74 - 99] or had no evidence of TB on chest radiographs [97%; 95% CI: 81 - 100]. These data demonstrate that MODS is effective at detecting TB in HIV-positive individuals, including those who are smear-negative or present normal chest radiographs.

Learning Objectives:

• Recognize current limitations in diagnosing TB among hospitalized HIV-infected individuals living in the developing world.
• Identify the usefulness of MODS in detecting culture-positive TB among HIV-positive patients living within a resource-limited setting.
• Determine whether blanket vs. selected TB screening using MODS should take place among hospitalized HIV in-patients living in a high TB burden setting.

Keywords: Tuberculosis, HIV/AIDS

Presenting author's disclosure statement:

Any relevant financial relationships? No

Recorded presentation