Asymptomatic Summertime Shedding of Respiratory Viruses

Abstract

To determine rates of both symptomatic and asymptomatic infection among ambulatory adults, we collected nasopharyngeal swab specimens, demographic characteristics, and survey information from 1477 adult visitors to a New York City tourist attraction during April-July 2016. Multiplex polymerase chain reaction analysis was used to identify specimens positive for common respiratory viruses. A total of 7.2% of samples tested positive for respiratory viruses; among positive samples, 71.0% contained rhinovirus, and 21.5% contained coronavirus. Influenza virus, respiratory syncytial virus, and parainfluenza virus were also detected. Depending on symptomatologic definition, 57.7%-93.3% of positive samples were asymptomatic. These findings indicate that significant levels of asymptomatic respiratory viral shedding exist during summer among the ambulatory adult population.

Detection of Influenza and Other Respiratory Viruses in Air Sampled From a University Campus: A Longitudinal Study

“…IAVs and IBVs were detected at higher frequencies than other respiratory viruses. A recent study that collected nasopharyngeal swabs of 2685 tourists in New York City reported a higher detection frequency for HRV and HCoV than IAV at 3.2%, 2.4%, and 0.2%, respectively [6,7]. To attain a comprehensive understanding on the potential transmission modes for respiratory viruses, future studies should sample concurrently from humans and their surrounding environment.…”

“…A substantial global disease burden is attributed to influenza virus and respiratory syncytial virus (RSV), which cause lower respiratory infections and cardiopulmonary complications [1][2][3][4]. While most infections are associated with acute respiratory illnesses, respiratory viruses can also infect without causing symptoms [5][6][7], although the infectivity of asymptomatic cases is uncertain. A common feature of respiratory viruses is their ability to spread via multiple non-mutually exclusive modes, by direct contact or indirectly via large droplets, fine droplet nuclei, or fomites [8][9][10][11].…”

“…It is currently unknown if people with mild or subclinical respiratory infections, who are capable to continue their daily activities in the community without substantial impediment, may also release virus-laden particles with airborne transmission potential. A recent study reported molecular detection of respiratory viruses in nasal swabs among 6.2% of adult tourists in New York City, of which >65% of positive cases were asymptomatic [6,7]. Public locations where infected and susceptible hosts converge may serve as hotspots within a transmission network during epidemics.…”

Respiratory virus infection among hospitalized adult patients with or without clinically apparent respiratory infection: a prospective cohort study

“…In the current study, patients in the non-fever/RS group were admitted to hospital for acute non-respiratory symptoms. Hence, our patient cohort differs from studies involving asymptomatic adult individuals who were not clinically affected by the respiratory viruses [11,27,29]. Further studies are required to determine whether there is a causal relationship between the identified respiratory virus and the symptoms among patients in the fever/RS group.…”

“…It is possible that these respiratory viruses are transient, colonizing the patients' upper respiratory tract but not actually causing the symptoms or disease. However, although asymptomatic infections due to adenovirus and PIV are often found in children [11,27,28], adenovirus and PIV are rarely detected among healthy asymptomatic adults [11,29].…”