Influenza
Conditions
Keywords
Influenza, Rapid flu test, Returning travelers with fever
Brief summary
Influenza is a frequent cause of fever in returning travelers. Usually diagnosis rests on the clinical picture. Rapid flu tests are becoming increasingly popular, although their sensitivity and specificity are suboptimal. The objective of this study is to evaluate if rapid flu tests influence the medical management of returning travelers with fever, a population at intermediate risk for influenza infections.
Detailed description
Travelers are at risk of acquiring infectious diseases. Previous studies have estimated that about 11% of travelers develop fever during or shortly after their trip abroad. Influenza has been shown to be one of the most important cause of fever amongst travelers. A sero-epidemiological survey showed that 27 of 211 patients (12.8%) with fever during or after a trip abroad developed antibodies against the influenza virus. Another study showed that 13% of travellers, who consulted after return with flu-like symptoms, had PCR or culture-proven influenza. The incidence of influenza in travellers varies according to the seasons, but cases can be seen year round. In tropical countries transmission is year-long and in the southern hemisphere the flu epidemics occur during the summer of the northern hemisphere. In most hospitals no confirmatory test for influenza is routinely done. For special cases a PCR or viral culture can be requested, but the results are only available after 48 hours for the PCR and after several days for the culture. It is suspected that the inability to confirm the diagnosis of flu contributes to the request of a greater number of useless investigations and inappropriate use of anti-infective treatments. Rapid diagnostic tests are easy to use, relatively cheap and they yield a result within a clinically relevant time frame (30 minutes). For the detection of influenza there are a variety of rapid diagnostic tests on the market. The reported sensitivities and specificities are quite variable, but the new generations report median sensitivities of 70 - 75% and median specificities between 90 and 95%. The rapid tests are considered most useful in patient populations with a significant proportion of influenza cases. The WHO encourages to use rapid diagnostic tests for influenza in returning travelers with fever, considering that this patient population is at significant risk of acquiring influenza during their trip. The aim of this study is to evaluate if rapid flu tests influence the medical management of returning travelers with fever
Interventions
DEVICEBD Directigen EZ Flu A+B
Naso-pharyngeal swab and rapid flu test
OTHERControl
No rapid flu test
Sponsors
University of Lausanne Hospitals
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Adults 18 years or older * Returning from abroad within the last 14 days * Documented fever of 38oC or above or anamnestic fever + cough or sore throat within the last 4 days before the consultation.
Exclusion criteria
* Unwillingness to participate
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Cost for the Medical Management of Patients | 4 years |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Chest X-ray Requested | 4 years | Number of patients for whom a chest X-ray was requested as part of the medical management |
| Number of Patients Receiving a Prescription for Antibiotics | 4 years | — |
Countries
Switzerland
Participant flow
Recruitment details
Participants were recruited between January 2009 and November 2012.
Participants by arm
| Arm | Count |
|---|---|
| Rapid Test Returning travelers with fever will have a rapid flu test BD Directigen EZ Flu A+B done on a naso-pharyngeal swab | 60 |
| Comparator Returning travelers with fever will benefit of the usual medical care, without rapid flu test | 33 |
| Total | 93 |
Baseline characteristics
| Characteristic | Comparator | Total | Rapid Test |
|---|---|---|---|
| Age, Continuous | 35 years | 35 years | 35 years |
| Race and Ethnicity Not Collected | — | 0 Participants | — |
| Region of Enrollment Switzerland | 33 Participants | 93 Participants | 60 Participants |
| Sex: Female, Male Female | 15 Participants | 43 Participants | 28 Participants |
| Sex: Female, Male Male | 18 Participants | 50 Participants | 32 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 60 | 0 / 33 |
| other Total, other adverse events | 0 / 60 | 0 / 33 |
| serious Total, serious adverse events | 0 / 60 | 0 / 33 |
Outcome results
Primary
Cost for the Medical Management of Patients
Time frame: 4 years
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Rapid Test | Cost for the Medical Management of Patients | 581 USD |
| Comparator | Cost for the Medical Management of Patients | 661 USD |
Secondary
Chest X-ray Requested
Number of patients for whom a chest X-ray was requested as part of the medical management
Time frame: 4 years
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Rapid Test | Chest X-ray Requested | 9 Participants |
| Comparator | Chest X-ray Requested | 2 Participants |
Secondary
Number of Patients Receiving a Prescription for Antibiotics
Time frame: 4 years
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Rapid Test | Number of Patients Receiving a Prescription for Antibiotics | 14 Participants |
| Comparator | Number of Patients Receiving a Prescription for Antibiotics | 13 Participants |