Effect of Influenza Vaccination of Healthcare Workers (HCW) on the Risk of Influenza in Patients Hospitalized in Short Stays Units

Not Applicable

Completed

• Conditions: Patient With Influenza Like Illness
• Interventions: Biological: A nasal swab

• Registration Number: NCT02198638
• Lead Sponsor: Hospices Civils de Lyon

Brief Summary

Hospital acquired influenza is associated with significant morbidity and mortality in hospitalized patients notably elderly patients. Vaccination of HCW is recommended to prevent influenza transmission in healthcare setting.

Outbreaks of hospital acquired influenza were reported in stays with high vaccine coverage in patients (higher than 85%). It is necessary to underline that an adequate vaccine cover in the elderly population will not necessarily result in a total control of the incidence. Consequently, the prevention of influenza outbreaks in this vulnerable population must also include the reduction of the exposure to the influenza viruses, in particular thanks to the vaccination of HCW.

A pilote case-control study, implemented in Edouard Herriot hospital (at Lyon University hospitals), indicates that a shielding effect of more than 35% of vaccinated HCW on hospital acquired influenza among patients (Bénet et al.; BMC Infectious Diseases 2012). The results suggest a protective effect but investigations, carried out on a more important sample are needed to validate the benefit of HCW vaccination.

The aim of this prospective multicentric cohort study is to estimate incidence of influenza among hospitalized patients according to % of influenza vaccination of HCW in short stay units.

Detailed Description

Not available

Study Timeline

• Study Start: 2013-12
• Study First Submitted: 2014-07-15
• Study First Submitted QC: 2014-07-22
• Study First Posted: 2014-07-23
• Primary Completion: 2015-04
• Study Completion: 2015-04
• Status Verified: 2015-05
• Last Update Submitted: 2015-05-12
• Last Update Posted: 2015-05-13

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 541

Inclusion Criteria

• All adults patients and healthcare workers of the participating units
• With Influenza Like Illness

Exclusion Criteria

• Patients aged < 18 years

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Patients or healthcare workers	A nasal swab	-

Primary Outcome Measures

Name	Time	Method
Incidence of influenza among hospitalized patients according to % of influenza vaccination of HCW in short stay units	After 16 months (2 influenza seasons: from 15 December 2013 to 15 April 2014 and from 15 December 2014 to 15 April 2015)	Study participation was proposed to each patient who presented ILI (influenza like illness) at admission or during hospitalization. ILI was defined as fever \>37.8°C or cough or sore throat. Vaccination against influenza during the ILI season was collected by oral interview. After the interview, a nasal swab was performed by a research assistant and influenza virus infection was confirmed by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction on viral cultures.

Secondary Outcome Measures

Name	Time	Method
Estimation of influenza vaccine failure according to serotyping of viral strains	After 16 months (2 influenza seasons: from 15 December 2013 to 15 April 2014 and from 15 December 2014 to 15 April 2015)	strains of confirmed influenza virus were analysed by reverse transcription-polymerase chain reaction on viral cultures.
Does incidence of community influenza influence hospital acquired influenza infections	After 16 months (2 influenza seasons: from 15 December 2013 to 15 April 2014 and from 15 December 2014 to 15 April 2015)	comparison of results observed during the 2 seasons

Trial Locations

Locations (2)

Centre Hospitalier Universitaire - Saint Etienne; 🇫🇷 Saint Etienne, France

Hospices Civils de Lyon - Hôpital Edouard Herriot; 🇫🇷 Lyon, France