Background: Viral respiratory infections are a major cause of pediatric illness. It is not known whether seasonality of viruses differs between Aboriginal and non-Aboriginal children of varying ages.
Methods: We extracted data on respiratory syncytial virus (RSV), influenza viruses A and B, parainfluenza virus types 1, 2, and 3 and adenovirus identified through cell culture or direct immunofluorescence between 1997 and 2005 from nasopharyngeal or throat specimens at Western Australia's only pediatric hospital. We used harmonic analysis in generalized linear models to examine the variations in seasonality of these viruses with Aboriginality and age.
Results: A respiratory virus was identified in 32% of 32 741 specimens. RSV (18.6%), influenza virus A (5.1%), and parainfluenza virus 3 (4.0%) were most common. The median age at time of identification was lower in Aboriginal children than non-Aboriginal for all viruses except RSV. Seasonality differed between all viruses and varied with age for RSV, influenza viruses and adenovirus. Influenza viruses A and B activity peaked earlier in Aboriginal than non-Aboriginal children during 1997, 1998, and 2002.
Conclusions: All viruses showed distinct seasonality. Variability with age and different seasonal patterns for influenza viruses in Aboriginal children compared with non-Aboriginal children has to be taken into account when identifying target groups and timing for vaccination and other interventions.
From the *Telethon Institute for Child Health Research, Centre for Child Health Research, The University of Western Australia, Perth, Australia; †School of Paediatrics and Child Health, The University of Western Australia, Perth, Australia; ‡Department of Microbiology, PathWest Laboratory Medicine, Princess Margaret Hospital for Children, Perth, Australia; and §Australian Biosecurity Cooperative Research Centre for Emerging Infectious Disease, Curtin University of Technology, Perth, Australia.
Accepted for publication December 22, 2008.
Supported by grants (353514) from National Health and Medical Research Council Program (to H.M., D.L.).
Address for correspondence: Hannah Moore, BSc (Hons), GradDipClinEpi, PhD Candidate, Division of Population Sciences, Telethon Institute for Child Health Research, PO Box 855, West Perth WA, Australia 6872. E-mail: firstname.lastname@example.org.
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