Rule-out outbreak: 24-hour metagenomic next-generation sequencing for characterizing respiratory virus source for infection prevention

Background. Metagenomic next-generation sequencing (mNGS) has been used to uncover unusual causes of infectious diseases but has not been used routinely for the investigation of putative nosocomial outbreaks. Here, we describe the use of mNGS during investigation of a cluster of human rhinovirus (HRV)-positive infections on a high-risk pulmonary ward. Methods. We performed mNGS on 6 midnasal turbinate swabs from 4 case-patients and 10 swabs from 9 control outpatients that tested positive for enterovirus/rhinovirus by the FilmArray system. Results. HRV reads were recovered in 15 (94%) of the 16 samples sequenced. Phylogenetic analysis of HRV whole genomes from the 4 case-patients and 5 outpatient controls along with partial genomes from additional outpatient controls revealed that isolates from the case-patients were not directly related and that the 2 closest case HRV genomes had an estimated time to most recent common ancestor of 172 years. Our turnaround time from receipt of the sample to phylogenetic analysis was 24 hours. Conclusions. We found the use of mNGS downstream of a rapid polymerase chain reaction respiratory panel during an investigation of 4 hospital-acquired rhinovirus infections to rapidly dispel concern of a single-source transmission event.