Development of secondary bacterial pneumonia in adults presenting with influenza versus noninfluenza viral respiratory infection

Kathryn H Melamed; Justin Williams; Xiaoyan Wang; Scott Hu; Christopher Nguyen; Jing Cui; Jane C Deng

doi:10.1177/1753466620963026

Development of secondary bacterial pneumonia in adults presenting with influenza versus noninfluenza viral respiratory infection

Ther Adv Respir Dis. 2020 Jan-Dec:14:1753466620963026. doi: 10.1177/1753466620963026.

Authors

Kathryn H Melamed¹, Justin Williams², Xiaoyan Wang³, Scott Hu¹, Christopher Nguyen⁴, Jing Cui⁵, Jane C Deng^{6

7}

Affiliations

¹ Division of Pulmonary and Critical Care Medicine, University of California at Los Angeles, Los Angeles, CA, USA.
² Department of Biostatistics, University of California at Los Angeles, Los Angeles, CA, USA.
³ Department of General Internal Medicine and Health Services Research, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA.
⁴ Department of Pulmonary Medicine, Kaiser Oakland Medical Center, Oakland, CA, USA.
⁵ Department of Cardiothoracic Anesthesiology, Morristown Medical Center, Morristown, NJ, USA.
⁶ Pulmonary and Critical Care Medicine, Veterans Affairs Ann Arbor Healthcare System, 2215 Fuller Road, 111G (Pulmonary), Ann Arbor, MI 48105, USA.
⁷ Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI, USA.

Abstract

Background: Respiratory viral infections, particularly influenza, are known to cause significant morbidity and mortality, often due to secondary infections. Our aim was to comparatively analyze the incidence, epidemiology, and outcomes of secondary pneumonia in adult patients hospitalized with influenza versus noninfluenza viral infections and determine whether influenza particularly predisposes to secondary infections.

Methods: This was a retrospective analysis from a single tertiary medical center of adult patients admitted to the hospital between 2008 and 2010 with respiratory viral infections. Microbiological patterns and clinical outcomes were compared between those with influenza (VI, n = 57) and those with noninfluenza (NI, n = 77) respiratory viral infections.

Results: The NI group was older (60.6 ± 14.0 versus 53.3 ± 19.7 years, p = 0.019) with higher rates of lung transplantation (29% versus 9%, p = 0.009) than VI. Overall, 35% developed secondary pneumonia, higher among NI (44%) than VI (23%, p = 0.017). Staphylococcus aureus was the most common cause of pneumonia in VI, whereas Gram-negative rods were most frequently identified in NI. The NI group had longer hospital [median 10 (interquartile range (IQR) 6-19) versus 6 (IQR 4-15) days, p = 0.019] and intensive care unit [median 4 (IQR 0-12) versus 0 (IQR 0-8) days, p = 0.029] stays compared with VI. Further, the NI group was more likely to be admitted to the intensive care unit compared with VI (62% versus 39%, p = 0.011). A trend towards increased mortality was observed in viral infections complicated by secondary pneumonia than primary viral infections (28% versus 15%, p = 0.122).

Conclusion: Secondary pneumonia is common among adults hospitalized with viral respiratory infections. Within our population, NI results in more frequent secondary pneumonia and longer hospital stays than those with VI. Given the high number of infections caused by Gram-negative rods, monitoring local epidemiology is critical for guiding initial antibiotic selection in empirical treatment of secondary infections.The reviews of this paper are available via the supplemental material section.

Keywords: bacterial pneumonia; influenza; polymicrobial infections; secondary infections; viral pneumonia.

Publication types

Comparative Study

MeSH terms

Adult
Aged
Anti-Bacterial Agents / therapeutic use
Coinfection*
Cross Infection / diagnosis
Cross Infection / drug therapy
Cross Infection / epidemiology
Cross Infection / microbiology*
Female
Hospitalization
Humans
Incidence
Influenza, Human / diagnosis
Influenza, Human / epidemiology
Influenza, Human / therapy
Influenza, Human / virology*
Male
Middle Aged
Pneumonia, Bacterial / diagnosis
Pneumonia, Bacterial / drug therapy
Pneumonia, Bacterial / epidemiology
Pneumonia, Bacterial / microbiology*
Prognosis
Retrospective Studies
Risk Assessment
Risk Factors
Time Factors

Substances

Anti-Bacterial Agents