Performance of direct immunofluorescence assay for the detection of human metapneumovirus under clinical laboratory settings.

Wolf, Jonas Michel; Gregianini, Tatiana Schäffer; Seadi, Claudete Maria Farina; Tumioto, Gabriela Luchiari; Dambrós, Bibiana Paula; Lehmann, Fernanda Kieling Moreira; Carli, Silvia De; Ikuta, Nilo; Lunge, Vagner Ricardo

INTRODUCTION Human metapneumovirus (hMPV) is an emergent human respiratory pathogen. This study aimed to evaluate the performance of direct immunofluorescence (DIF) to detect hMPV in a clinical laboratory setting. METHODS Nasopharyngeal aspirate samples (448) of children and adults with respiratory illness were used to detect hMPV by using DIF and real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assays. RESULTS In all, 36 (8%) samples were positive by DIF and 94 (21%) were positive by qRT-PCR. Direct immunofluorescence specificity was 99% and sensitivity was 38%. CONCLUSIONS DIF is not very sensitive under clinical laboratory settings.