Metagenomic Next-Generation Sequencing for Diagnosis of Pulmonary Infections

Despite pneumonia being a leading cause of morbidity and mortality worldwide, diagnostics remains a challenge, hindering rapid organism identification and subsequent effective treatments. Current microbiological methods include culture, serology, and limited molecular panels. While helpful, these methods are unable to address the full range of potential pathogens (e.g., fastidious or noncultivable organisms or uncommon organisms not included in current panels). Metagenomic next-generation sequencing (mNGS) is a molecular technique that analyzes and compares the nucleic acid content in a patient sample to a reference database of organisms that may include bacteria, viruses, fungi, and/or parasites, depending on the mNGS technology used. By bypassing the limitations of culture and targeted molecular assays, mNGS offers the potential to identify countless organisms directly from a patient specimen to aid in the diagnosis of an infectious process. Although promising, mNGS does have considerable limitations related to cost, interpretation, standardization, clinical relevance, turnaround time (TAT), and widespread availability. Thus, these factors should be considered prior to implementing mNGS for clinical use. Moreover, additional studies are required to fully understand the clinical and epidemiological impact of mNGS for the diagnosis of infectious diseases, including respiratory infections.