Poor outcomes among elderly patients hospitalized for influenza-like illness

Abstract

Background and objective: Global Influenza Hospital Surveillance Network is a worldwide initiative that aims to document the burden of influenza infections among acute admissions and vaccine effectiveness in particular countries. As a partner of this platform, we aimed to determine the frequency of influenza infections among acute admissions with influenza-like illness and the outcomes of enrolled patients during the 2015–2016 influenza season in selected hospitals in Turkey.

Patients and methods: The investigators screened the hospital admission registries, chart review or available records, and screened all patients hospitalized in the previous 24–48 hours or overnight in the predefined wards or emergency room. A total of 1351 patients were screened for enrollment in five tertiary care referral hospitals in Ankara and 774 patients (57.3% of the initial screened population) were eligible for swabbing. All of the eligible patients who consented were swabbed and tested for influenza with real-time polymerase chain reaction (PCR) based methods.

Results: Overall, influenza positivity was detected in 142 patients (18.4%). The predominant influenza strain was A H1N1pdm09. Outcomes were worse among elderly patients, regardless of the presence of the influenza virus. Half of the patients over 65 years of age were admitted to the intensive care unit, while one third required any mode of mechanical ventilation and one fourth died in the hospital in that particular episode.

Conclusion: These findings can guide hospitals to plan and prepare for the influenza season. Effective influenza vaccination strategies, particularly aimed at the elderly and adults with chronic diseases, can provide an opportunity for prevention of deaths due to influenza-like illness.

Keywords:

• Influenza
• influenza-like illness
• viral infection
• mortality
• elderly

Transparency

Declaration of funding

This research was funded by the Turkish Society of Internal Medicine, Foundation for Influenza Epidemiology and Sanofi Pasteur within the context of Global Influenza Hospital Surveillance Network.

Declaration of financial/other relationships

M.D.T. has disclosed that she received scientific meeting travel grants from Sanofi Pasteur. T.B.B., L.O., E.B., Ö.G.T., Ö.Ö., N.T., M.Ö., H.T., T.B.D., A.K., S.T.B., K.A., A.O.-P., B.G. and S.U. have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article.

CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgements

We would like to thank to the investigators in the participating centers.

We also thank Gizem Yılmaz for assisting in data gathering and recording for the preparation of the Excel data sheets, and to Mrs Ayse Dora for her hospitality and help during the project.