Human metapneumovirus (hMPV) is a newly discovered respiratory pathogen with limited epidemiological data available. currently, the only available method to diagnose hMPV is by cell culture followed by reverse transcription-polymerase chain reaction (RT-PCR). The purpose of this clinical trial is to test the performance of a new diagnostic method. Light Diagnostics Human Metapneumovirus Direct Immunoflourescence Assay (DFA), in comparison to RT-PCR for the diagnosing of possible hMPV infection in random clinical specimens.