Nosocomial infection: A risk factor for a complicated course in children with respiratory syncytial virus infection – Results from a prospective multicenter German surveillance study

Abstract

Background

Nosocomially acquired respiratory syncytial virus infections (RSV-NI) may cause serious problems in hospitalized paediatric patients. Hitherto, prospectively collected representative data on RSV-NI from multicenter studies in Germany are limited.

Methods

The DMS RSV Ped database was designed for the prospective multicenter documentation and analysis of clinically relevant aspects of the management of inpatients with RSV-infection. The study covered six consecutive seasons (1999–2005); the surveillance took place in 14 paediatric hospitals in Germany.

Results

Of the 1568 prospectively documented RSV-infections, 6% (n=90) were NI and 94% (n=1478) were community acquired (CA). A significantly higher proportion in the NI group displayed additional risk factors like prematurity, chronic lung disease, mechanical ventilation (med. history), congenital heart disease, and neuromuscular impairment. Of all NI, 55% occurred in preterms (30.6% of all RSV-infections in preterms with severe chronic lung disease of prematurity were NI). Illness severity as well as the total mortality, but not the attributable mortality was significantly higher in the NI group. In the multivariate analysis, NI was significantly associated with the combined outcome ‘complicated course of disease’.

Conclusion

This is the first prospective multicenter study from Germany, which confirms the increased risk of a severe clinical course in nosocomially acquired RSV-infection. Of great concern is the high rate of (preventable) NI in preterms, in particular in those with severe chronic lung disease or with mechanical ventilation due to other reasons.

Introduction

Respiratory syncytial virus (RSV) is the single most prevalent etiologic agent in paediatric viral respiratory tract infection (Black, 2003; Ogra, 2004). RSV is responsible for the majority of episodes of acute wheezing triggered by infection (Jennings et al., 2004), bronchiolitis (Fitzgerald and Kilham, 2004) and pneumonia (McIntosh, 2002) predominantly during the first 24 months of life. About 1–2% of all RSV-infected children require hospital care. The RSV-related hospitalization rate and the risk of severe complications are increased in prematurely born infants with chronic lung disease (CLD) (Meissner, 2003) and in children with hemodynamically relevant congenital heart disease (CHD) (Buckingham et al., 2001; Feltes et al., 2003), other forms of chronic lung disease or severe neuromuscular impairment (Arnold et al., 1999; Panitch, 2004). Forster et al. (2004) estimated (95% CI) an average of 26,524 (23,812–29,432) RSV-related hospitalizations per year in children younger than 3 years in Germany (i.e. 38% of all paediatric hospitalizations for viral lower respiratory tract infection). The same group calculated €2772 as median total costs per hospitalized RSV-infection (Cox et al., 2001; Ehlken et al., 2005; Terletskaia-Ladwig et al., 2005). Others recently calculated even higher costs (Rietveld et al., 2004). Specific therapeutic agents with proven efficacy against RSV are still not available (Black, 2003; Fitzgerald and Kilham, 2004). Meticulous hand hygiene after patient contact together with other barrier precautions are considered to be of utmost importance for the prevention of nosocomial transmission (Simon et al., 2006; Thorburn et al., 2004). Nosocomial RSV-infection significantly increases the length of stay in hospital (Howard et al., 2000; Thwaites and Piercy, 2004) and thus the total cost of treatment. Systematic efforts to reduce the incidence of nosocomial RSV-infections have been shown to be cost effective (Macartney et al., 2000).

A specific software tool developed at our institution for the targeted surveillance of hospitalized RSV-infected patients (database for the inpatient management of RSV-infections in paediatrics: DSM RSV Paed) was available for data entry in 1999.

Recently, we published our monocentric results, collected from 1999 to 2002 in this journal, considering the epidemiology and control of nosocomial RSV-infections (Simon et al., 2006). The analysis presented here covers 1568 RSV-infections, prospectively documented in 14 paediatric treatment centers in Germany (1999–2005).

It aims at the confirmation and extension of our monocentric results out of the multicenter DSM RSV Paed database and it focuses on the risk factor ‘nosocomial infection’. Results from this database, considering other particular risk factors (prematurity and neuromuscular impairment) have been submitted for separate publications (Simon and coworkers; Wilkesmann and coworkers).