Epidemiological and clinical features of respiratory viral infections in hospitalized children during the circulation of influenza virus A(H1N1) 2009

Department of Pediatrics, Sacco Hospital, University of Milan, Milan, Italy.
Influenza and Other Respiratory Viruses (Impact Factor: 2.2). 05/2011; 5(6):e528-34. DOI: 10.1111/j.1750-2659.2011.00264.x
Source: PubMed


Seasonal influenza viruses and respiratory syncytial virus (RSV) are primary causes of acute respiratory tract infections (ARTIs) in children. New respiratory viruses including human metapneumovirus (hMPV), human bocavirus (hBoV), and influenza 2009 A(H1N1) virus have a strong impact on the pediatric population.
To evaluate epidemiological and clinical features of ARTIs in hospitalized children.
From December 1, 2008, to December 31, 2009, all children under age fifteen (n = 575) hospitalized for ARTIs were investigated for influenza A (subtype H1N1, H3N2, and 2009 H1N1) and B, RSV A and B, hMPV, and hBoV by PCR.
Fifty-one percent of samples were positive for these respiratory viruses. The frequencies of virus detection were RSV 34·1%, hBoV 6·8%, hMPV 5%, seasonal influenza A 5%, and seasonal influenza B 0%. From April 2009, 11·6% of collected samples were influenza 2009 A(H1N1) positive. Respiratory syncytial virus activity peaked in January, hBoV in February, and hMPV in April. Seasonal influenza A was detected only between January and April 2009, while influenza 2009 A(H1N1) peaked in November. Respiratory syncytial virus and hMPV were mainly associated with lower respiratory tract infections (LRTIs) and with necessity of O(2) administration. The 2009 pandemic influenza was more frequently detected in elder children (P < 0·001) and was associated with higher, longer-lasting fevers compared with other viral infections (P < 0·05).
All considered viruses were involved in LRTIs. The primary clinical relevance of RSV and a similar involvement of both seasonal influenza and emerging viruses investigated were observed on the pediatric population.

Download full-text


Available from: Gianvincenzo Zuccotti, Sep 29, 2014
12 Reads
  • Source
    • "Recent papers on epidemiology and outcomes in hospitalised children have compared H1N1pdm09 influenza with historical data on seasonal influenza. Some of these studies report a worsening of the disease burden with H1N1pdm09 influenza, either as higher hospitalisation or mortality rates or more severe disease [31, 55, 68, 135] and others report large increases in the hospitalisation rate for ILI during the first months of the pandemic compared with previous seasons [75, 118]. Consistent with the experience from previous pandemics, hospitalised children with H1N1pdm09 infections were significantly older than those hospitalised with seasonal influenza (range of median ages, 2–5 and 0–2 years, respectively) [31, 55, 118, 135]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Unlabelled: The burden of influenza is unevenly distributed, with more severe outcomes in children aged <5 years than older children and adults. In spite of this, immunisation policies for young children are far from universal. This article provides an overview of the published evidence on the burden of influenza in children worldwide, with a particular interest in the impact of pandemic influenza in 2009-2010 (caused by the H1N1pdm09 virus). In an average season, up to 9.8 % of 0- to 14-year olds present with influenza, but incidence rates can be markedly higher in younger children. Children aged <5 years have greater rates of hospitalisation and complications than their older counterparts, particularly if the children have co-existing illnesses; historically, this age group have had higher mortality rates from the disease than other children, although during the 2009-2010 pandemic the median age of those who died of influenza was higher than in previous seasons. Admissions to hospital and emergency departments appear to have been more frequent in children with H1N1pdm09 infections than during previous seasonal epidemics, with pneumonia continuing to be a common complication in this setting. Outcomes in children hospitalised with severe disease also seem to have been worse for those infected with H1N1pdm09 viruses compared with seasonal viruses. Studies in children confirm that vaccination reduces the incidence of seasonal influenza and the associated burden, underlining the importance of targeting this group in national immunisation policies. Conclusions: Children aged <5 years are especially vulnerable to influenza, particularly that caused by seasonal viruses, and vaccination in this group can be an effective strategy for reducing disease burden.
    European Journal of Pediatrics 05/2013; 173(3). DOI:10.1007/s00431-013-2023-6 · 1.89 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This study was performed to compare the clinical features of pediatric patients who were diagnosed with influenza A (H1N1) or seasonal influenza A and B during 2009 and 2010 at a single institution.
    01/2011; 21(4):269. DOI:10.7581/pard.2011.21.4.269
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Clin Microbiol Infect 2012; 18: E197–E199 Human papillomavirus (HPV) causes cutaneous and mucosal infections in both adults and children. In order to evaluate HPV prevalence and the spectrum of genotypes in the oral cavity of paediatric subjects, a retrospective study was carried out on oral-pharyngeal swabs collected from 177 newborns aged 0–6 months. HPV-DNA was detected by a nested-PCR; the viral typing was made through DNA sequencing. HPV infection was identified in 25 subjects (14.1%) and the sequence analysis showed eight distinct genotypes. These data confirm HPV detection in newborn oral mucosa. Further investigations are needed to clarify the methods of HPV acquisition.
    Clinical Microbiology and Infection 03/2012; 18(6):E197-9. DOI:10.1111/j.1469-0691.2012.03839.x · 5.77 Impact Factor
Show more