Poster Abstract Session: TB: Mycobacteria Diagnostic Testing
Thursday, October 8, 2015
Room: Poster Hall
Three people die of TB every minute worldwide. More than 80% of the cases are Pulmonary TB (PTB), which is 100% responsible of the disease transmission. The sputum smear microscopy is the most used tool for TB diagnosis in low and middle-income countries; it is an inexpensive, fast, and specific method, but is not highly sensitive. Colombia is a developing country with an estimated TB incidence of 32 cases per 100000 people and where more than 40% of the total cases are Sputum Smear-Negative (SSN). This condition is a common problem faced by clinicians in every part of the world and according to epidemiology studies could be responsible even of 40% of the disease spread. In such cases the histopathology of the lung tissue is a helpful diagnostics tool. Objective.
To describe and analyze retrospectively at a university hospital in Bogotá, Colombia the usefulness of histopathological examination of lung biopsies in the rapid diagnosis of cases SSN PTB-culture positive, which were collected over a six years period.
Methods: Pathological, microbiological and clinical databases from Jan-2008 to May-2014, were reviewed. Two Pulmonary Pathologist independently, using Hematoxylin-Eosin and Ziehl-Neelsen stains, were who evaluated each biopsy study. When was necessary, the staining and study process was repeated and was discussed together other pathologists.
Results: 95 PTB cases were diagnosed by solid media-culture, of which in 58 a lung biopsy was taken; of all only 2 cases were Sputum Smear Positive. The culture positive samples were 49 BAL; 27 sputa and 19 lung biopsies. 47 transbronchial biopsies and 11 open lung biopsies were studied histologically. Necrotic granulomas were the most frequent finding (81%); 39 (67%) biopsies showed acid-fast Bacilli in the ZN stain. The histopathology and clinical features favored the rapid diagnosis of PTB in 90% of the evaluated cases. 24 hours was the average time for informing results in each case.
Conclusion: According to our results, the lung biopsy histopathology is an excellent tool for rapidly diagnosing PTB in Colombia.