Microbiologia Médica e Diagnóstico

Comparison of Various Laboratory Detection Methods for Diagnosing Pulmonary Aspergillosis

Abstract

Sadaf Riyaz, Nazish Fatima, Harris M Khan and Shameem M

Aspergillus is a mould which may lead to a variety of infectious, allergic diseases depending on the immune status or pulmonary structure of the host. Invasive pulmonary aspergillosis occurs primarily in patients with severe immunodeficiency. Early and rapid diagnosis of systemic fungal infections remain limited, despite intensive efforts by many investigators. Few clinical guidelines have been previously proposed for either diagnosis or management of Pulmonary Aspergillosis. The current study was undertaken for comparing various detection methods like conventional direct microscopy or histopathology, culture methods, immunological (GM ELISA) and molecular methods (PCR). To identify carcinoma cell types and to categorize Aspergillosis types histopathology was done. For direct fungal examination, culture, Aspergillus polymerase chain reaction (PCR), and galactomannan (GM) detection, bronchoalveolar lavage (BAL) fluids were collected. In this study microscopy was found to have low sensitivity of (70.5%) while culture had highest specificity (97.6%). GM assay showed a sensitivity of 100% and a specificity of 86.4% whereas PCR has an overall sensitivity of 100% and a specificity of 81.3%. Thus, we suggest that both BAL PCR and GM ELISA may be beneficial for use in early diagnosis of Aspergillosis, especially those patients who do not demonstrate radiological signs.