Does Viral Co-Infection Influence the Severity of Acute Respiratory Infection in Children?

Abstract

Background Multiple viruses are often detected in children with respiratory infection but the significance of co-infection in pathogenesis, severity and outcome is unclear. Objectives To correlate the presence of viral co-infection with clinical phenotype in children admitted with acute respiratory infections (ARI). Methods We collected detailed clinical information on severity for children admitted with ARI as part of a Spanish prospective multicenter study (GENDRES network) between 2011–2013. A nested polymerase chain reaction (PCR) approach was used to detect respiratory viruses in respiratory secretions. Findings were compared to an independent cohort collected in the UK. Results 204 children were recruited in the main cohort and 97 in the replication cohort. The number of detected viruses did not correlate with any markers of severity. However, bacterial superinfection was associated with increased severity (OR: 4.356; P-value = 0.005), PICU admission (OR: 3.342; P-value = 0.006), higher clinical score (1.988; P-value = 0.002) respiratory support requirement (OR: 7.484; P-value < 0.001) and longer hospital length of stay (OR: 1.468; P-value < 0.001). In addition, pneumococcal vaccination was found to be a protective factor in terms of degree of respiratory distress (OR: 2.917; P-value = 0.035), PICU admission (OR: 0.301; P-value = 0.011), lower clinical score (-1.499; P-value = 0.021) respiratory support requirement (OR: 0.324; P-value = 0.016) and oxygen necessity (OR: 0.328; P-value = 0.001). All these findings were replicated in the UK cohort. Conclusion The presence of more than one virus in hospitalized children with ARI is very frequent but it does not seem to have a major clinical impact in terms of severity. However bacterial superinfection increases the severity of the disease course. On the contrary, pneumococcal vaccination plays a protective roleThis work was supported by the Spanish Government (Research Program Health Research Fund (FIS; PI10/00540) National Plan I + D + I and FEDER funds), by Regional Galician funds (Promotion of Research Project 10 PXIB 918 184PR) (FMT), by Ministerio de Ciencia e Innovación (SAF2011-26983), and by the Plan Galego IDT, Xunta de Galicia (EM 2012/045) (AS). A grant was received from the Sistema Universitario Gallego -Modalidad REDES (2014-PG139) from the Xunta de Galicia (to AS and FMT). MCL research activities have been supported by grants from Instituto de Investigación Sanitaria de Santiago de Compostela. FMT research activities have been supported by grants from Instituto Carlos III (Intensificación de la actividad investigadora). Investigators received funding from the European Union’s seventh Framework program under ECGA no. 279185 (EUCLIDS) during the production of this paper. JH was supported by the Imperial College Comprehensive Biomedical Research Centre and the Wellcome Trust Centre for Respiratory Infection at Imperial College (DMPED P26077 to JH). Micropathology Ltd. provided support in the form of salaries for authors ES and CF, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ sectionS