Transmission of Influenza Virus From Asymptomatic Healthcare Workers and Inpatients in the Acute Care Hospital Setting

NCT02478905 | Completed

• 1 other identifier: KEK-ZH-Nr. 2015-0228
• Study Type: observational
• Target: 700
• Locations: 1 country
• Sites: 1

Brief Summary

The epidemiology and transmission dynamics of influenza in hospitals are only poorly understood, particularly with respect to subjects without symptoms of influenza infection (e.g. without fever, cough, sore throat, nasal congestion, weakness, headache, loss of appetite, or myalgia). Knowledge about whether asymptomatic subjects are able to transmit influenza is of major importance. If they do transmit influenza, vaccination of patients and healthcare workers (HCW) before start of the influenza season, the permanent use of masks by HCW during influenza season, and quarantine for previously exposed inpatients may be the only available measures to reduce the number of influenza transmission events from asymptomatic subjects in acute care hospitals. Closure of this knowledge gap would be of major benefit to infection prevention and control recommendations, and may in turn reduce morbidity and mortality associated with influenza in hospitals through improved patient management.

Conditions

Human Influenza

Outcome Measures

Primary Outcomes (1)

• Secondary attack rate of asymptomatic or presymptomatic influenza among inpatients, among acute care workers and between inpatients and acute care HCW in an acute care hospital setting

  diagnosed by positive influenza PCR from flocked mid-turbinate nasal swab collected in symptomatic or asymptomatic individuals following face-to-face contact with an individual with symptomatic influenza infection on the day of contact.

  up to 6 months

Secondary Outcomes (11)

• Secondary attack rate of symptomatic influenza among inpatients, among acute care workers and between inpatients and acute care HCW in an acute care hospital setting

  up to 6 months

• Proportion of asymptomatic and symptomatic inpatients with influenza infection upon hospital admission: as diagnosed by influenza polymerase chain reaction (PCR) from flocked mid-turbinate nasal swabs collected upon hospital admission

  up to 6 months

• Incidence of asymptomatic (A5) and symptomatic (A6) nosocomial influenza in hospital inpatients, defined as the number of emerging influenza infections >72 hours after hospital admissions per 100 patient-days

  up to 6 months

• Incidence of asymptomatic (A7) and symptomatic (A8) influenza in acute care hospital workers defined as the number of influenza infections per 100 HCW per influenza season

  up to 6 months

• Association of individual influenza symptoms with influenza transmission from subjects with symptomatic influenza infection

  up to 6 months

Study Arms (1)

surveillance cohort

Flocked mid-turbinate nasal swabs for influenza PCR will be collected from study participants daily

Other: Influenza

Interventions

Influenza OTHER

surveillance cohort

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

This project is a prospective study following patients in medical wards and acute care HCW (including nursing staff (nurses and assistant nurses), physiotherapists, house staff with direct patient contact and medical doctors (clinical fellows) working on the same wards at the University Hospital Zurich. Inpatients and HCW will be recruited from general medical and infectious diseases wards, pulmonology wards, hematology wards and from the stem cell transplant unit. All HCW and inpatients on the ward under surveillance are eligible for the study

You may qualify if:

• or more years of age;
• Available for follow-up during the study period;
• If a HCW: employed full- or part-time (≥50% full-time equivalent);
• Understand the study, agree to its provisions, and give written informed consent (as documented by signature).

You may not qualify if:

• If a HCW: planning to spend more than two consecutive weeks outside of Switzerland during the winter study period (November 1st to April 31st);
• If a HCW: planning to take leave from work for more than two consecutive weeks during the winter study period (e.g. maternity or medical leave);
• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders or dementia of the subject;
• Known or suspected non-compliance.

Sponsors & Collaborators

• University of Zurich: lead
• Schweizerischer Nationalfonds: collaborator

Study Sites (1)

University Hospital Zurich

Zurich, Switzerland

Location

Related Publications (2)

• Kuster SP, Boni J, Kouyos RD, Huber M, Schmutz S, Shah C, Bischoff-Ferrari HA, Distler O, Battegay E, Giovanoli P, Guckenberger M, Kohler M, Muller R, Petry H, Ruschitzka F, McGeer A, Coleman BL, Sax H, Weber R, Trkola A. Absenteeism and presenteeism in healthcare workers due to respiratory illness. Infect Control Hosp Epidemiol. 2021 Mar;42(3):268-273. doi: 10.1017/ice.2020.444. Epub 2020 Nov 26.

  PMID: 33239124 DERIVED

• Schwarz H, Boni J, Kouyos RD, Turk T, Battegay E, Kohler M, Muller R, Petry H, Sax H, Weber R, McGeer A, Trkola A, Kuster SP. The TransFLUas influenza transmission study in acute healthcare - recruitment rates and protocol adherence in healthcare workers and inpatients. BMC Infect Dis. 2019 May 21;19(1):446. doi: 10.1186/s12879-019-4057-5.

  PMID: 31113375 DERIVED

Biospecimen

Retention: SAMPLES WITH DNA

Virological analyses * Influenza A and B PCR from nasal swabs * Whole genome sequencing of positive swabs

MeSH Terms

Conditions

Influenza, Human

Interventions

Influenza Vaccines

Condition Hierarchy (Ancestors)

Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Viral Vaccines; Vaccines; Biological Products; Complex Mixtures

Study Officials

• Stefan Kuster, MD

  Division of Infectious Diseases and Hospital Epidemiology

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 1 Year
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 5, 2015
• First Posted: June 23, 2015
• Study Start: January 1, 2016
• Primary Completion: June 1, 2017
• Study Completion: June 1, 2017
• Last Updated: October 31, 2017

Record last verified: 2017-10

Locations

CH (1)