Research paper
Hospital acquired viral respiratory tract infections: An underrecognized nosocomial infection

https://doi.org/10.1016/j.idh.2020.02.002Get rights and content

Highlights

  • HAVRI contribute significantly to mortality and morbidity regardless of virus species.

  • Influenza A is the most common HAVRI in adults.

  • Increased incidence in HAVRI was observed over the study period.

Abstract

Background

Our study aimed to describe the incidence, epidemiology of respiratory viruses and outcomes in hospital acquired viral respiratory infections (HAVRI).

Methods

We conducted a retrospective observational study on all adults and children with hospital acquired viral respiratory infections between July 2012 and April 2019. Clinical and microbiological data were collected in a major tertiary level hospital in North Queensland. Morbidity indicators were the length of stay, need for intensive care and mechanical ventilation. Length of stay was analyzed with the Kruskal-Wallis test and mortality with the Chi-Square test.

Results

A total of 283 patients tested positive for a respiratory virus and fulfilled the criteria for a hospital acquired infection. Individuals in the younger age group were more likely to be admitted to intensive care and need mechanical ventilation. A higher mortality was found with individuals in the older age category. The morbidity and mortality did not differ based on the virus type. Influenza A was the most common respiratory virus associated with hospital acquired viral respiratory infections.

Conclusion

Hospital acquired viral respiratory infections contribute significantly to morbidity and mortality regardless of the virus species.

Introduction

Hospital acquired infections are a major cause of morbidity, mortality and increased hospital expenditure [1]. A systematic review by Mitchell et al. [2] noted the paucity of data on these infections in Australia. This inadequacy is felt even more with respect to nosocomial viral respiratory infections. Our study assumes significance in this context, as it is one of few that attempts to understand the epidemiology of these infections in both adults and children in a major tertiary hospital in North Queensland, Australia.

Respiratory viral infections have been studied in specific groups of patients. These include those who have undergone hematopoietic stem cell or solid organ transplants [3]. Little is known about the impact of these infections in the non-transplant population and our study targeted this group of patients. Influenza and respiratory syncytial viruses (RSV) are the most commonly encountered viruses in nosocomial pneumonia, the latter being particularly common in the pediatric population [4]. Patients with cardiac and chronic pulmonary or kidney disease are at risk of acquiring influenza and suffer the complications such as secondary bacterial infection.

Outbreaks in hospitals can occur via transmission from infected patients, health care workers and visitors who introduce the virus into the hospital environment. Early detection of the virus, prophylactic oseltamivir, isolation and strict personal protective measures have contained outbreaks of influenza in children on chemotherapy [5]. However, all these measures may not be practical for large outbreaks involving different virus species as they can overwhelm hospital resources. Studies have shown that isolation precautions are associated with higher costs and increased length of stay in hospitals [6,7]. Increased incidence of depression and delirium have also been noted in these patients [8]. This necessitates reevaluation of infection control measures in outbreaks of HAVRI.

Approximately 20% of patients with health care-associated pneumonia have viral respiratory infections, with an incidence that typically reflects the level of virus activity within the community [9,10]. Our study aimed to collect demographic and clinical data for patients with positive viral respiratory swabs over 7 years (between 2012 and 2019). Children were studied separately from adults. As mortality data alone cannot reflect the burden of HAVRI, we chose the need for intensive care, mechanical ventilation and length of stay as morbidity indicators, and this was analysed for different age groups. We also analysed the occurrence of outbreaks of these infections.

Section snippets

Study design and location

We chose a retrospective observational design as the aim was to observe the changing trends in the incidence of these infections over the study period. The study was approved by the Human Research Ethics Committee of the Hospital (LNR/2019/QTHS/53733). The hospital is a public tertiary level hospital in Northern Australia with 700 beds with a variety of medical and surgical specialties that include cardiothoracic and neurosurgical units. All the clinical areas that were included in the study

Results

292 patients with positive respiratory swabs for hospitalised patients over the study period were identified. Of these, 283 patients met the definition of HAVRI based on our inclusion criteria. There was an increase in the incidence of the infections over the years with the rate of infection increasing from 0.63 to 3.38 per 10,000 bed days (Fig. 1.)

The incidence of different virus types is described in Fig. 2. Influenza A was the commonest at 35% (n = 101). A significant association (p < 0.01)

Discussion

The study provides much needed insight on the impact of HA-VRI on morbidity and mortality in hospitalized patients of different age groups. HA-VRI has been shown to be associated with negative outcomes in neonates including prolonged hospitalization, a need for respiratory support, and an increased risk of developing bronchopulmonary dysplasia (BPD) [10,11]. We found similar results in our study with the younger age group more likely to need intensive care and mechanical ventilation. However,

Ethics

The study was approved by the Human Research Ethics Committee of the Hospital (LNR/2019/QTHS/53733). This study had low risk to participants and we requested a waiver of consent with the HREC due to the following reasons.

  • 1.

    Involvement in the study will not affect patient's wellbeing as this is entirely a retrospective study. There will be review of patients' management but no direct contact of patients involved. There will be no identifiable data presented in the final report.

  • 2.

    The potential

Authorship statement

N. Manchal: Project design, Data collection, Supervision, Writing, Editing; R. Norton: Project design, Supervision, Editing; R. Mohammad: Project design, Data collection, Editing; M. Ting: Project design, Data collection, Editing; F. Francis: Project design, Supervision, Editing; H. Luetchford: Project design, Data collection, Writing, Editing; J. Carrucan: Project design, Data collection, Writing, Editing.

Conflict of interest

All authors report no conflicts of interest relevant to this article.

Funding

None reported.

Provenance and peer review

Not commissioned; externally peer reviewed.

Acknowledgements

Dr. Daniel Lindsay for statistical analysis.

References (22)

  • E.J. Chow et al.

    Hospital-acquired respiratory viral infections: incidence, morbidity, and mortality in pediatric and adult patients

    Open Forum Infect Dis

    (2017)
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