title: Prospective evaluation of rhinovirus infection in healthy young children.
abstract: BACKGROUND
  Although the incidence of human rhinovirus (HRV) infection is highest in young, no study has yet been published concerning the types of HRV circulating in this population, the incidence of symptomatic infections due to the different types, or duration of shedding
  
  
  OBJECTIVE
  This prospective study evaluated the circulation of HRV species and types, and established the incidence of asymptomatic and symptomatic infections in young children.
  
  
  METHODS
  The study enrolled 93 healthy children aged <2 years, 88 of whom completed the follow-up of weekly household visits from November 2013 to February 2014. At each visit, a record was made of any signs and symptoms of acute infection, and a nasopharyngeal (NP) swab was taken in order to identify the HRVs by means of RT-polymerase chain reaction and to construct the phylogenetic tree of the HRV-positive cases.
  
  
  RESULTS
  A total of 1408 NP samples were obtained and 326 HRV infections were diagnosed (23.1%), leading to a mean number of 3.7 ± 2.3 infections per child: HRV-A in 72 cases (22.1%), HRV-B in 29 (8.9%), HRV-C in 122 (37.4%), and non-typeable HRV in 103 (31.6%). Shedding was significantly longer for HRV-A (14 days) and HRV-B (14 days) than HRV-C (7 days; p = 0.002 and p = 0.012). Most of the HRV infections (209/326, 64.1%) remained asymptomatic and, when symptomatic, were of marginal clinical relevance.
  
  
  CONCLUSIONS
  In healthy young children, HRV infection is extremely frequent, generally asymptomatic or with a mild clinical presentation, and viral shedding is limited in time.
authors: Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors: Nicola
authors: N
authors: Principi
authors: Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors: Alberto
authors: A
authors: Zampiero
authors: Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors: Monia
authors: M
authors: Gambino
authors: Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors: Alessia
authors: A
authors: Scala
authors: Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors: Laura
authors: L
authors: Senatore
authors: Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors: Mara
authors: M
authors: Lelii
authors: Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors: Beatrice
authors: B
authors: Ascolese
authors: Department of Epidemiology, IRCCS Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
authors: Claudio
authors: C
authors: Pelucchi
authors: Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy. Electronic address: susanna.esposito@unimi.it.
authors: Susanna
authors: S
authors: Esposito
mesh_terms: D058070:Asymptomatic Diseases / Q000453:epidemiology; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D010802:Phylogeny; D010850:Picornaviridae Infections / Q000453:epidemiology* / Q000821:virology*; D011446:Prospective Studies; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012229:Rhinovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA; D017201:Virus Shedding
keywords: Children; Pediatric infectious diseases; Picornaviridae; Respiratory tract infection; Rhinovirus; Viral shedding