Asymptomatic Shedding of Respiratory Virus among an Ambulatory Population across Seasons

Abstract

Respiratory viruses are common in human populations, causing significant levels of morbidity. Understanding the distribution of these viruses is critical for designing control methods. However, most data available are from medical records and thus predominantly represent symptomatic infections. Estimates for asymptomatic prevalence are sparse and span a broad range. In this study, we aimed to measure more precisely the proportion of infections that are asymptomatic in a general, ambulatory adult population. We recruited participants from a New York City tourist attraction and administered nasal swabs, testing them for adenovirus, coronavirus, human metapneumovirus, rhinovirus, influenza virus, respiratory syncytial virus, and parainfluenza virus. At recruitment, participants completed surveys on demographics and symptomology. Analysis of these data indicated that over 6% of participants tested positive for shedding of respiratory virus. While participants who tested positive were more likely to report symptoms than those who did not, over half of participants who tested positive were asymptomatic.

Longitudinal active sampling for respiratory viral infections across age groups

“…Conversely, the impact of these infectious agents on healthy adults and the role of asymptomatic infections on transmission dynamics have not been properly investigated. A recent study found high levels of asymptomatic respiratory infection among an ambulatory adult population in New York City …”

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.…”

Controverse : pour ou contre la PCR multiplexe dans les infections respiratoires

“…Ces technologies qui augmentent considérablement notre éventail de données microbiologiques suscitent beaucoup d'interrogations sur la physiopathologie des maladies infectieuses en particuliers sur la notion d'infection asymptomatique et de rôle pathogène ou l'importance clinique des coinfections. La fréquence de détection d'agents pathogènes respiratoires chez les patients asymptomatiques varie avec l'âge, (20-50 % chez l'enfant et 2-50 % chez l'adulte selon les études), le nombre d'enfants vivant au foyer familial ou l'agent pathogène en cause (plus de cas symptomatiques avec le virus de la grippe, VRS, hMPV) [13][14][15][16][17][18]. De même, les patients immunodéprimés peuvent avoir une excrétion prolongée de microorganismes ou d'acides nucléiques non infectieux détectés par PCR sans nécessairement avoir de symptômes cliniques associés.…”