Active surveillance documents rates of clinical care seeking due to respiratory illness.

Marta Galanti,Benjamin Lane,Peter Dayan,Devon Comito,Minhaz Ud‐Dean,Ruthie Birger,Bo Shopsin,Ioan Filip,Chanel Ligon,Nelsa Matienzo,Greg A Freyer,Raul Rabadan,Haruka Morita,Simon Anthony,Jeffrey Shaman,Atinuke Shittu,Eudosie Tagne,Sadiat Ibrahim

doi:10.1111/irv.12753

Abstract

BackgroundRespiratory viral infections are a leading cause of disease worldwide. However, the overall community prevalence of infections has not been properly assessed, as standard surveillance is typically acquired passively among individuals seeking clinical care.MethodsWe conducted a prospective cohort study in which participants provided daily diaries and weekly nasopharyngeal specimens that were tested for respiratory viruses. These data were used to analyze healthcare seeking behavior, compared with cross‐sectional ED data and NYC surveillance reports, and used to evaluate biases of medically attended ILI as signal for population respiratory disease and infection.ResultsThe likelihood of seeking medical attention was virus‐dependent: higher for influenza and metapneumovirus (19%‐20%), lower for coronavirus and RSV (4%), and 71% of individuals with self‐reported ILI did not seek care and half of medically attended symptomatic manifestations did not meet the criteria for ILI. Only 5% of cohort respiratory virus infections and 21% of influenza infections were medically attended and classifiable as ILI. We estimated 1 ILI event per person/year but multiple respiratory infections per year.ConclusionStandard, healthcare‐based respiratory surveillance has multiple limitations. Specifically, ILI is an incomplete metric for quantifying respiratory disease, viral respiratory infection, and influenza infection. The prevalence of respiratory viruses, as reported by standard, healthcare‐based surveillance, is skewed toward viruses producing more severe symptoms. Active, longitudinal studies are a helpful supplement to standard surveillance, can improve understanding of the overall circulation and burden of respiratory viruses, and can aid development of more robust measures for controlling the spread of these pathogens.

Highlights

Respiratory infections are a leading cause of morbidity and mortality globally and impose a high burden on economic productivity and medical and public health systems
In New York City (NYC), a survey conducted by the Department of Health and Mental Hygiene (DOHMH) estimated that each Emergency Department-attended ILI corresponds to roughly 60 illnesses in the community.[14]
Medically attended illness (MA)-respiratory disease not recognized by the ILI classification

Summary

| INTRODUCTION

Respiratory infections are a leading cause of morbidity and mortality globally and impose a high burden on economic productivity and medical and public health systems (hospitalizations, visits, therapeutics). New and improved vaccines and therapeutics for many common respiratory viruses—respiratory syncytial virus (RSV), rhinovirus, human metapneumovirus (HMPV)—are currently under evaluation or development; because many infected persons do not seek clinical care, the true burden of each of these viruses is not known This circumstance complicates predictive quantification of the cost effectiveness of each intervention and its ability to control targeted pathogens in the broader population. In New York City (NYC), a survey conducted by the Department of Health and Mental Hygiene (DOHMH) estimated that each Emergency Department-attended ILI corresponds to roughly 60 illnesses in the (adult) community.[14] Both survey- and web-based approaches have some important limitations They overlook asymptomatic and mild infections, which are important from an epidemiological vantage. By using a very unique dataset, we endeavored to quantify the prevalence of respiratory viral infections and illnesses among the general population and to capture healthcare seeking behavior

| METHODS

Findings

| DISCUSSION