title: Heterogeneous shedding of influenza by human subjects and its implications for epidemiology and control.
abstract: Heterogeneity of infectiousness is an important feature of the spread of many infections, with implications for disease dynamics and control, but its relevance to human influenza virus is still unclear. For a transmission event to occur, an infected individual needs to release infectious particles via respiratory symptoms. Key factors to take into account are virus dynamics, particle release in relation to respiratory symptoms, the amount of virus shed and, importantly, how these vary between infected individuals. A quantitative understanding of the process of influenza transmission is relevant to designing effective mitigation measures. Here we develop an influenza infection dynamics model fitted to virological, systemic and respiratory symptoms to investigate how within-host dynamics relates to infectiousness. We show that influenza virus shedding is highly heterogeneous between subjects. From analysis of data on experimental infections, we find that a small proportion (<20%) of influenza infected individuals are responsible for the production of 95% of infectious particles. Our work supports targeting mitigation measures at most infectious subjects to efficiently reduce transmission. The effectiveness of public health interventions targeted at highly infectious individuals would depend on accurate identification of these subjects and on how quickly control measures can be applied.
authors.affiliation: Centre for Immunity, Infection &Evolution, University of Edinburgh, UK.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Canini
authors.affiliation: Centre for Immunity, Infection &Evolution, University of Edinburgh, UK.
authors.forename: Mark E J
authors.initials: ME
authors.lastname: Woolhouse
authors.affiliation: Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Taronna R
authors.initials: TR
authors.lastname: Maines
authors.affiliation: INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France.|Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France.|Assistance Publique Hôpitaux de Paris, Hôpital Saint Antoine, Paris, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Carrat
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control* / Q000635:transmission*; D008297:Male; D008954:Models, Biological; D017201:Virus Shedding