Rapid Flu Tests in Travelers With Fever

Utility of Rapid Flu Tests in the Medical Management of Returning Travelers With Fever

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.

Study Overview

• Status: Completed
• Conditions: Influenza
• Intervention / Treatment: Device: BD Directigen EZ Flu A+B; Other: Control

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

• Study Type: Interventional
• Enrollment (Actual): 93
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Basel, Switzerland, 4002
    • Tropical Institute Basel
  • Lausanne, Switzerland, 1011
    • Medical outpatient clinic, University Hospital of Lausanne

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Rapid test; Returning travelers with fever will have a rapid flu test	Device: BD Directigen EZ Flu A+B; Naso-pharyngeal swab and rapid flu test; Other Names: BD Directigen EZ Flu A+B, serial number 8010589
Sham Comparator: Comparator; Returning travelers with fever will benefit of the usual medical care, without rapid flu test	Other: Control; No rapid flu test

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Cost for the Medical Management of Patients	4 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Chest X-ray Requested	Number of patients for whom a chest X-ray was requested as part of the medical management	4 years
Number of Patients Receiving a Prescription for Antibiotics		4 years

Collaborators and Investigators

• Sponsor: University of Lausanne Hospitals
• Investigators: Principal Investigator: Serge de Valliere, MD, Medical outpatient clinic, University Hospital of Lausanne

Publications and helpful links

General Publications

• Berthod D, Genton B, Hatz C, Blum J, de Valliere S. Ability of physicians to diagnose influenza and usefulness of a rapid influenza antigen test in febrile returning travelers: A randomized controlled trial. Travel Med Infect Dis. 2015 Sep-Oct;13(5):394-9. doi: 10.1016/j.tmaid.2015.08.001. Epub 2015 Aug 28.

Study record dates

Study Major Dates

• Study Start: January 1, 2009
• Primary Completion (Actual): May 1, 2015
• Study Completion (Actual): May 1, 2015

Study Registration Dates

• First Submitted: January 12, 2009
• First Submitted That Met QC Criteria: January 12, 2009
• First Posted (Estimate): January 13, 2009

Study Record Updates

• Last Update Posted (Actual): April 2, 2020
• Last Update Submitted That Met QC Criteria: March 23, 2020
• Last Verified: March 1, 2020

More Information

Terms related to this study

• Keywords: Influenza; Rapid flu test; Returning travelers with fever
• Additional Relevant MeSH Terms: RNA Virus Infections; Virus Diseases; Infections; Respiratory Tract Infections; Respiratory Tract Diseases; Orthomyxoviridae Infections; Influenza, Human
• Other Study ID Numbers: PMU-Flu