Open Access Research article

Characterisation of acute respiratory infections at a United Kingdom paediatric teaching hospital: observational study assessing the impact of influenza A (2009 pdmH1N1) on predominant viral pathogens

Emily A Lees1*, Enitan D Carrol2, Christine Gerrard3, Fiona Hardiman3, Gareth Howel4, Alison Timmis5, Kent Thorburn6, Malcolm Guiver7 and Paul S McNamara8

Author Affiliations

1 Wolfson Centre for Personalised Medicine, University of Liverpool, Block A: Waterhouse Building, 1-5 Brownlow Street, Liverpool L69 3GL, England

2 Institute of Infection and Global Health, University of Liverpool, The Ronald Ross Building, 8 West Derby Street, Liverpool L69 7BE, England

3 Microbiology Department, Alder Hey Children’s NHS Foundation Trust Hospital, Eaton Road, Liverpool L12 2AP, England

4 Hull Royal Infirmary, Anlaby Road, Hull HU3 2JZ, England

5 Department of Paediatrics, Countess of Chester NHS Foundation Trust, Liverpool Road, Chester CH2 1UL, England

6 Paediatric Intensive Care Unit, Alder Hey Children’s NHS Foundation Trust Hospital, Eaton Road, Liverpool L12 2AP, England

7 Molecular Diagnostics Department, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WZ, England

8 Institute of Child Health, Alder Hey Children’s NHS Foundation Trust Hospital, Eaton Road, Liverpool L12 2AP, England

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BMC Infectious Diseases 2014, 14:343  doi:10.1186/1471-2334-14-343

Published: 19 June 2014

Abstract

Background

According to the World Health Organisation, influenza A (2009 pdmH1N1) has moved into the post-pandemic phase, but there were still high numbers of infections occurring in the United Kingdom in 2010-11. It is therefore important to examine the burden of acute respiratory infections at a large children’s hospital to determine pathogen prevalence, occurrence of co-infection, prevalence of co-morbidities and diagnostic yield of sampling methods.

Methods

This was a retrospective study of respiratory virus aetiology in acute admissions to a paediatric teaching hospital in the North West of England between 1st April 2010 and 31st March 2011. Respiratory samples were analysed either with a rapid RSV test if the patient had symptoms suggestive of bronchiolitis, followed by multiplex PCR testing for ten respiratory viruses, or with multiplex PCR testing alone if the patient had suspected other ARI. Patient demographics and data regarding severity of illness, presence of co-morbidities and respiratory virus sampling method were retrieved from case notes.

Results

645 patients were admitted during the study period. 82/645 (12.7%) patients were positive for 2009 pdmH1N1, of whom 24 (29.2%) required PICU admission, with 7.3% mortality rate. Viral co-infection occurred in 48/645 (7.4%) patients and was not associated with more severe disease. Co-morbidities were present more frequently in older children, but there was no significant difference in prevalence of co-morbidity between 2009 pdmH1N1 patients and those with other ARI. NPA samples had the highest diagnostic yield with 192/210 (91.4%) samples yielding an organism.

Conclusions

Influenza A (2009 pdmH1N1) is an ongoing cause of occasionally severe disease affecting both healthy children and those with co-morbidities. Surveillance of viral pathogens provides valuable information on patterns of disease.

Keywords:
H1N1; Influenza; Paediatrics; Virology; Co-morbidities