InfluenzaAFPNCT02868658
Asymptomatic Flu Project
A study testing Blood sampling and Nasal swab in people with Influenza, run by Hospices Civils de Lyon at 1 site in France.
Trial summary
Although clinical presentation of influenza is often symptomatic, asymptomatic cases also occur. The knowledge of the incidence of asymptomatic influenza among healthcare workers is very important because of the risk of cross-transmission to hospitalized patients. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Influenza
- What is being tested?
- Blood sampling and Nasal swab
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 289 participants
- Where
- 1 siteFrance
- Study dates
- 4 Oct 2016to 21 Mar 2017
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Volunteer health-care workers
- Working in the following wards: short-stay, inpatient (including ICU) and emergency
Who cannot join
- Presence of influenza symptoms at enrolment
- Programmed absence (maternity leave, vacation, etc.)
- Administrative agents
Trial locations and contacts
1 site in 1 country.
France1 site
Edouard Herriot Hospital; Department of Epidemiology, Hygiene and Public Health
Lyon, 69437
About this study
Official title: Incidence of Symptomatic and Asymptomatic Influenza Among Healthcare Workers : A Multicenter Cohort Study
Although clinical presentation of influenza is often symptomatic, asymptomatic cases also occur. The knowledge of the incidence of asymptomatic influenza among healthcare workers is very important because of the risk of cross-transmission to hospitalized patients. The principal objective of the study is to estimate the incidence of symptomatic and asymptomatic influenza among healthcare workers in short-stay wards. The results of this study will lead to a better understanding of the burden of asymptomatic influenza among healthcare workers and might be used as an argument to increase influenza vaccine coverage among healthcare workers.
- Conditions
- Influenza
- Being tested
- Blood sampling, Nasal swab
- Keywords
- Influenza, health care workers, nosocomial, asymptomatic, France
- Medical subject headings
- Influenza, Human
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Blood samplingBiological
Nasal swabOther
| Study group | Role | What they receive |
|---|---|---|
| Health-care workers | Experimental | Health-care workers recruited in the study will have blood sampling and naso-pharyngeal bottle-brush sampling Receives: Biological: Blood sampling; Other: Nasal swab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of influenza cases
Incidence of asymptomatic and symptomatic influenza per 1000 days at risk among healthcare workers
Measured: 6 months after inclusion
Secondary outcomes (5)
Fraction of asymptomatic influenza cases
Fraction of asymptomatic influenza cases among patients with confirmed influenza infection (seroconversion)
Measured: 6 months after inclusion
Stratified incidence ratios
The objective is to compare the proportion of asymptomatic influenza among vaccinated and unvaccinated healthcare workers, stratified on the type of influenza virus , gender, age, and other covariates
Measured: 6 months after inclusion
Incidence of influenza-like illness
The objective is to calculate the incidence of influenza-like illness without virological confirmation
Measured: 6 months after inclusion
proportion of health-care workers with Influenza vaccine coverage
The objective is to estimate the vaccination coverage against influenza among health care workers
Measured: 6 months after inclusion
Number of sick-leave days per participating ward
The objective is to estimate the professional impact of influenza in a population of healthcare workers
Measured: 6 months after inclusion
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Aug 2016 (estimated)
- Study start4 Oct 2016
- Primary completion21 Mar 2017
- Study completion21 Mar 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for InfluenzaStudies of the same condition, open and under way.
- More trials run by Hospices Civils de LyonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 289 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hospices Civils de Lyon
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02868658
- Sponsor's protocol ID
- 69HCL16_0095
- Acronym
- AFP
- Status last verified
- Dec 2025
- First submitted
- 11 Aug 2016
- Last updated
- 19 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Benet T, Amour S, Valette M, Saadatian-Elahi M, Aho-Glele LS, Berthelot P, Denis MA, Grando J, Landelle C, Astruc K, Paris A, Pillet S, Lina B, Vanhems P; AFP Study Group. Incidence of Asymptomatic and Symptomatic Influenza Among Healthcare Workers: A Multicenter Prospective Cohort Study. Clin Infect Dis. 2021 May 4;72(9):e311-e318. doi: 10.1093/cid/ciaa1109.
PubMed 32750120
Study at a glance
From the registry record, last updated by the sponsor on 19 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Incidence of Symptomatic and Asymptomatic Influenza Among Healthcare Workers : A Multicenter Cohort Study
- ClinicalTrials.gov ID
- NCT02868658
- Acronym / sponsor ID
- AFP / 69HCL16_0095
- Conditions
- Influenza
- Keywords
- Influenza, health care workers, nosocomial, asymptomatic, France
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 289 participants (actual)
- Lead sponsor
- Hospices Civils de LyonUniversity, hospital or other
- Study start
- 4 Oct 2016 (actual)
- Primary completion
- 21 Mar 2017 (actual)
- Study completion
- 21 Mar 2017 (actual)
- First posted
- 16 Aug 2016 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Although clinical presentation of influenza is often symptomatic, asymptomatic cases also occur. The knowledge of the incidence of asymptomatic influenza among healthcare workers is very important because of the risk of cross-transmission to hospitalized patients. The principal objective of the study is to estimate the incidence of symptomatic and asymptomatic influenza among healthcare workers in short-stay wards. The results of this study will lead to a better understanding of the burden of asymptomatic influenza among healthcare workers and might be used as an argument to increase influenza vaccine coverage among healthcare workers.
Study design
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Health-care workers | Experimental | Biological: Blood sampling, Other: Nasal swabHealth-care workers recruited in the study will have blood sampling and naso-pharyngeal bottle-brush sampling |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Volunteer health-care workers
- Working in the following wards: short-stay, inpatient (including ICU) and emergency
Key exclusion criteria (3 listed)
- Presence of influenza symptoms at enrolment
- Programmed absence (maternity leave, vacation, etc.)
- Administrative agents
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Blood sampling | Biological | Health-care workers |
| Nasal swab | Other | Health-care workers |
Primary outcome
Incidence of influenza cases
Time frame: 6 months after inclusion
Incidence of asymptomatic and symptomatic influenza per 1000 days at risk among healthcare workers
5 secondary outcomes
Fraction of asymptomatic influenza cases
Time frame: 6 months after inclusion
Stratified incidence ratios
Time frame: 6 months after inclusion
Incidence of influenza-like illness
Time frame: 6 months after inclusion
proportion of health-care workers with Influenza vaccine coverage
Time frame: 6 months after inclusion
Number of sick-leave days per participating ward
Time frame: 6 months after inclusion
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Dec 2025.
- Results publication: PubMed 32750120Benet T, Amour S, Valette M, Saadatian-Elahi M, Aho-Glele LS, Berthelot P, Denis MA, Grando J, Landelle C, Astruc K, Paris A, Pillet S, Lina B, Vanhems P; AFP Study Group. Incidence of Asymptomatic and Symptomatic Influenza Among Healthcare Workers: A Multicenter Prospective Cohort Study. Clin Infect Dis. 2021 May 4;72(9):e311-e318. doi: 10.1093/cid/ciaa1109.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Blood sampling and Nasal swab in people with Influenza, run by Hospices Civils de Lyon at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 19 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of influenza cases (time frame: 6 months after inclusion). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02868658, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Dec 2025.