Vulnerable Populations Demonstrated Similar Burden of Illness for RSV and Influenza

People experiencing homelessness (PEH) were found to have a similar prevalence and burden of illness of both respiratory syncytial virus (RSV) and influenza when testing those living in congregate settings, according to a study published in Influenza and Other Respiratory Viruses.

RSV is a disease found in individuals of all ages but is most prevalent in young children and older adults. Severe disease is possible in those with chronic medical conditions, which are more common in PEH. Medical and social vulnerabilities make PEH particularly vulnerable to contracting RSV. The goal of the study was to describe the burden of disease and clinical characteristics of PEH contracting RSV.

The study was done using a cross-sectional design and enrolled both residents and staff in homeless centers located in King County, Washington. The participants were enrolled between January 2019 to May 2021 using kiosks at 15 shelters throughout the county. Shelter residents 3 months or older with a new or worsening cough or who had 2 or more symptoms of acute respiratory infection (ARI) in the past 7 days were eligible. Fever, cough, sore throat, headache, shortness of breath, rhinorrhea, and myalgia were considered among the symptoms of ARI.

Participants were allowed to enroll once monthly regardless of symptoms as well. Eligibility for shelter staff was started on April 1, 2020. Participants were allowed multiple encounters, with each encounter including a questionnaire and a nasal swab. All encounters had to be 7 or more days removed from their previous encounter unless they developed new respiratory symptoms.

The researchers had 15,364 encounters between January 2019 and May 2021. The median age of the participants was 41 years (IQR, 25-55), 60% were men, and 21.9% were shelter staff. Comorbidities that were common in the group included asthma (12%), bronchitis (2.5%), and chronic obstructive pulmonary disease (COPD). Current tobacco use was found in 54% of adults.

There were 35 nasal specimens collected that tested positive for RSV (15 for RSV A and 21 for RSV B), with 1 participant who tested positive for both RSV A and B. There were 77 nasal specimans that tested positive for influenza (34 for influenza A and 44 for influenza B) with 1 participant who tested positive for both influenza A and B. There were 9 specimens that detected other viruses along with RSV (25.7%) and 16 specimens that detected other viruses along with influenza (20.8%).

Cough was the most common symptom in participants with RSV and influenza (89% and 71% respectively) along with rhinorrhea (86% and 69%). Myalgias (54%), sore throat (51%), and fatigue (49%) were common symptoms for RSV and fevers (47%), fatigue (40%), and myalgias (35%) common in influenza. There were 4 RSV infections and 11 influenza infections that were asymptomatic.

A total of 39% of those with symptomatic RSV and 58% of those with symptomatic influenza had an impact on their productivity and ability to perform regular activities due to their illness. There were 3 adults with RSV and 9 adults with influenza who had sought medical care in the previous week. There were also 2 participants with RSV and 1 participant with influenza who were part of the shelter staff. Encounters of RSV peaked in February of 2019 and again in December 2019, with no encounters after April of 2020.

There was no data on stably housed populations for a comparison and there was a lack of follow-up data on the participants. Longitudinal data was also lacking. Enrollment was also voluntary, which left residents who weren’t sampled.

The researchers concluded that this data represented the vulnerability of the PEH population. “RSV infection may soon be preventable or treatable with novel vaccines and therapeutics, and the medical and social vulnerabilities experienced by PEH make them an important potential target group for these future interventions,” they wrote.

Reference

McCulloch DJ, Rogers JH, Wang Y, et al. Respiratory syncytial virus and other respiratory viruses infections in residents of homeless shelters – King County, Washington, 2019-2021. Influenza Other Respir Viruses. 2023;17:e13166. doi:10.1111/irv.13166