Respiratory syncytial virus and other respiratory virus infections in residents of homeless shelters - King County, Washington, 2019-2021.

Respiratory syncytial virus (RSV) causes disproportionate morbidity and mortality in vulnerable populations. We tested residents of homeless shelters in Seattle, Washington for RSV in a repeated cross-sectional study as part of community surveillance for respiratory viruses. Of 15 364 specimens tested, 35 had RSV detected, compared to 77 with influenza. The most common symptoms for both RSV and influenza were cough and rhinorrhea. Many individuals with RSV (39%) and influenza (58%) reported that their illness significantly impacted their ability to perform their regular activities. RSV and influenza demonstrated similar clinical presentations and burden of illness in vulnerable populations living in congregate settings.

Genomic Characterization of Respiratory Syncytial Virus during 2022-23 Outbreak, Washington, USA.

We sequenced 54 respiratory syncytial virus (RSV) genomes collected during 2021-22 and 2022-23 outbreaks in Washington, USA, to determine the origin of increased RSV cases. Detected RSV strains have been spreading for >10 years, suggesting a role for diminished population immunity from low RSV exposure during the COVID-19 pandemic.

Genomic Analysis of Early Monkeypox Virus Outbreak Strains, Washington, USA.

We conducted a genomic analysis of monkeypox virus sequences collected early in the 2022 outbreak, during July-August , in Washington, USA. Using 109 viral genomes, we found low overall genetic diversity, multiple introductions into the state, ongoing community transmission, and potential for co-infections by multiple strains.

ORF-Interrupting Mutations in Monkeypox Virus Genomes from Washington and Ohio, 2022.

Monkeypox virus, the causative agent of the 2022 monkeypox outbreak, is a double-stranded DNA virus in the Orthopoxvirus genus of the Poxviridae family. Genes in terminal regions of Orthopoxvirus genomes mostly code for host-pathogen interaction proteins and are prone to selective pressure and modification events. Using viral whole genome sequencing, we identified twenty-five total clinical samples with ORF-disrupting mutations, including twenty samples encoding nonsense mutations in MPXVgp001/191 (OPG001), MPXVgp004/188 (OPG015), MPXVgp010 (OPG023), MPXVgp030 (OPG042), MPXVgp159 (OPG0178), or MPXVgp161 (OPG181). Additional mutations include a frameshift leading to an alternative C-terminus in MPXVgp010 (OPG023) and an insertion in an adenine homopolymer at the beginning of the annotated ORF for MPXVgp153 (OPG151), encoding a subunit of the RNA polymerase, suggesting the virus may instead use the start codon that encodes Met9 as annotated. Finally, we detected three samples with large (>900 bp) deletions. These included a 913 bp deletion that truncates the C-terminus of MPXVgp010 (OPG023); a 4205 bp deletion that eliminates MPXVgp012 (OPG025), MPXVgp013 (OPG027), and MPXVgp014 (OPG029) and truncates MPXVgp011 (OPG024; D8L) and MPXVgp015 (OPG030); and a 6881 bp deletion that truncates MPXVgp182 (OPG210) and eliminates putative ORFs MPXVgp184, MPXVgp185 (OPG005), and MPXVgp186, as well as MPXVgp187 (OPG016), and MPXVgp188 (OPG015) from the 3' ITR only. MPXVgp182 encodes the monkeypox-specific, highly immunogenic surface glycoprotein B21R which has been proposed as a serological target. Overall, we find greater than one-tenth of our sequenced MPXV isolates have at least one gene inactivating mutation and these genes together comprised greater than one-tenth of annotated MPXV genes. Our findings highlight non-essential genes in monkeypox virus that may be evolving as a result of selective pressure in humans, as well as the limitations of targeting them for therapeutics and diagnostic testing.

Human Parainfluenza Virus in Homeless Shelters before and during the COVID-19 Pandemic, Washington, USA.

To determine the epidemiology of human parainfluenza virus in homeless shelters during the COVID-19 pandemic, we analyzed data and sequences from respiratory specimens collected in 23 shelters in Washington, USA, during 2019-2021. Two clusters in children were genetically similar by shelter of origin. Shelter-specific interventions are needed to reduce these infections.

The Clinical and Genomic Epidemiology of Rhinovirus in Homeless Shelters-King County, Washington.

BACKGROUND: Rhinovirus (RV) is a common cause of respiratory illness in all people, including those experiencing homelessness. RV epidemiology in homeless shelters is unknown. METHODS: We analyzed data from a cross-sectional homeless shelter study in King County, Washington, October 2019-May 2021. Shelter residents or guardians aged ≥3 months reporting acute respiratory illness completed questionnaires and submitted nasal swabs. After 1 April 2020, enrollment expanded to residents and staff regardless of symptoms. Samples were tested by multiplex RT-PCR for respiratory viruses. A subset of RV-positive samples was sequenced. RESULTS: There were 1066 RV-positive samples with RV present every month of the study period. RV was the most common virus before and during the coronavirus disease 2019 (COVID-19) pandemic (43% and 77% of virus-positive samples, respectively). Participants from family shelters had the highest prevalence of RV. Among 131 sequenced samples, 33 RV serotypes were identified with each serotype detected for ≤4 months. CONCLUSIONS: RV infections persisted through community mitigation measures and were most prevalent in shelters housing families. Sequencing showed a diversity of circulating RV serotypes, each detected over short periods of time. Community-based surveillance in congregate settings is important to characterize respiratory viral infections during and after the COVID-19 pandemic. CLINICAL TRIALS REGISTRATION: NCT04141917.