Diagnostic Accuracy of Rapid Molecular Tests for Group A Streptococcal Pharyngitis Using Saliva Samples

NCT ID: NCT05521568

Last Updated: 2025-09-09

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 800 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2023-01-31
• Study Completion Date: 2025-02-28

Brief Summary

Observational study evaluating the diagnostic accuracy of rapid point-of-care molecular Group A strep diagnostic tests in saliva as compared to standard culture- and PCR-based techniques for the management of children aged 3-15 years of age presenting with sore throat to primary care.

Detailed Description

Group A streptococcus (GAS) is found in 20% to 40% of cases of childhood pharyngitis; the remaining cases are viral. Streptococcal pharyngitis ('strep throat') deserves antibiotics, while these are not indicated in viral cases. Because signs and symptoms of streptococcal and viral cases overlap, most guidelines recommend relying on a diagnostic test to identify Group A streptococcus to select who should receive antibiotics. In most settings, the first-line test to detect Group A Streptococcus is a rapid antigen detection test based on a throat swab, and the reference standard to identify streptococcal cases is throat culture. Recently, new rapid tests were developed. They use molecular techniques, such as rapid PCRs or LAMP, based on throat swabs. We hypothesize that these new molecular tests are sensitive enough to be performed on saliva swabs instead of throat swabs. Collecting saliva is less invasive and could be done by personnel with limited training.

Conditions

Streptococcal Pharyngitis

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Index test : Abbott ID NOW STREP A 2

Index test: Abbott ID NOW STREP A 2

Intervention Type: DIAGNOSTIC_TEST

The test under evaluation ('index test') is the rapid molecular test for Group A streptococcus Abbott ID NOW STREP A 2 (performed on saliva samples instead of throat swabs). This test was chosen because of its ease of use and several previous evaluations showing high diagnostic accuracy on throat swabs. The test gives a result after 2 to 6 minutes and will be performed by primary care practitioners participating in the study, in their office, using salivary swabs instead of throat swabs. Investigators will receive one session of specific training prior to the study. Saliva samples will be collected using the cotton swab that comes within the test packages. Index test results will not be used for patient management. Clinicians performing the rapid saliva test will not be blinded to clinical information.

Reference standard test : Composite of culture and PCR-based tests based on a throat swab

Reference standard test: Composite of culture and PCR-based tests based on a throat swab

Intervention Type: DIAGNOSTIC_TEST

Throat samples will be obtained by use of a double-swab collection-transportation system :

• Swab #1 will be used to perform the rapid antigen detection test (see below)
• Swab #2 will be held at ambient temperature and sent within 72 hours to Robert Debre Hospital microbiology laboratory. Throat swabs will be used to perform throat cultures using standard techniques (PMID: 22768060). Throat swabs will also be used to perform a PCR specific for Group A streptococcus (PMID: 23465407). Samples with a positive culture and/or a positive PCR test result will be classified as reference-standard-positives. Samples with a negative culture and a negative PCR will be classified as reference-standard-negatives. Investigators will be blinded to clinical data, including the result of the rapid antigen detection test and the rapid saliva test.

Comparator test : Rapid antigen detection test (usual care)

Comparator test: Rapid antigen detection test (usual care)

Intervention Type: DIAGNOSTIC_TEST

As per usual care, all children will undergo a rapid antigen detection test (StreptAtest, Biosynex), using Swab#1 (see above). This rapid antigen detection test is the one used in France and is the only commercial kit that is officially recommended by the National Health Insurance system. It detects Lancefield's Group A antigen, which is specific to Group A Streptococcus. The test will be performed by investigators, during consultation time. Clinicians performing the rapid antigen detection test will not be blinded to clinical information.

Interventions

Index test: Abbott ID NOW STREP A 2

The test under evaluation ('index test') is the rapid molecular test for Group A streptococcus Abbott ID NOW STREP A 2 (performed on saliva samples instead of throat swabs). This test was chosen because of its ease of use and several previous evaluations showing high diagnostic accuracy on throat swabs. The test gives a result after 2 to 6 minutes and will be performed by primary care practitioners participating in the study, in their office, using salivary swabs instead of throat swabs. Investigators will receive one session of specific training prior to the study. Saliva samples will be collected using the cotton swab that comes within the test packages. Index test results will not be used for patient management. Clinicians performing the rapid saliva test will not be blinded to clinical information.

Intervention Type: DIAGNOSTIC_TEST

Reference standard test: Composite of culture and PCR-based tests based on a throat swab

Throat samples will be obtained by use of a double-swab collection-transportation system :

• Swab #1 will be used to perform the rapid antigen detection test (see below)
• Swab #2 will be held at ambient temperature and sent within 72 hours to Robert Debre Hospital microbiology laboratory. Throat swabs will be used to perform throat cultures using standard techniques (PMID: 22768060). Throat swabs will also be used to perform a PCR specific for Group A streptococcus (PMID: 23465407). Samples with a positive culture and/or a positive PCR test result will be classified as reference-standard-positives. Samples with a negative culture and a negative PCR will be classified as reference-standard-negatives. Investigators will be blinded to clinical data, including the result of the rapid antigen detection test and the rapid saliva test.

Intervention Type: DIAGNOSTIC_TEST

Comparator test: Rapid antigen detection test (usual care)

As per usual care, all children will undergo a rapid antigen detection test (StreptAtest, Biosynex), using Swab#1 (see above). This rapid antigen detection test is the one used in France and is the only commercial kit that is officially recommended by the National Health Insurance system. It detects Lancefield's Group A antigen, which is specific to Group A Streptococcus. The test will be performed by investigators, during consultation time. Clinicians performing the rapid antigen detection test will not be blinded to clinical information.

Intervention Type: DIAGNOSTIC_TEST

Eligibility Criteria

Inclusion Criteria

• children 3-15 years
• seen in primary care (general practitioner or primary care pediatrician)
• with a diagnosis of acute pharyngitis defined as an inflammation of the pharynx and/or tonsils (erythema with or without exudate) or acute sore throat (even if without local signs of pharyngeal inflammation)
• non-opposition of the accompanying parent(s)

Exclusion Criteria

• children who received antibiotics within 7 days before inclusion
• children already enrolled in the study for the same episode of pharyngitis

• Minimum Eligible Age: 3 Years
• Maximum Eligible Age: 15 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Hôpital Necker-Enfants Malades

OTHER

Sponsor Role: collaborator

University Hospital, Paris

OTHER

Sponsor Role: collaborator

Groupe Hospitalier Diaconesses Croix Saint-Simon

OTHER

Sponsor Role: collaborator

Association Clinique Thérapeutique Infantile du val de Marne

OTHER

Sponsor Role: collaborator

Centre Hospitalier Intercommunal Creteil

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

ACTIV

Saint-Maur-des-Fossés, , France

Countries

France

References

Touitou R, Bidet P, Dubois C, Partouche H, Bonacorsi S, Jung C, Cohen R, Levy C, Cohen JF. Diagnostic accuracy of a rapid nucleic acid test for group A streptococcal pharyngitis using saliva samples: protocol for a prospective multicenter study in primary care. Diagn Progn Res. 2023 Jul 13;7(1):13. doi: 10.1186/s41512-023-00150-4.

Reference Type: DERIVED

PMID: 37443047 (View on PubMed)

Other Identifiers

PREDISTREP IX

Identifier Type: -

Identifier Source: org_study_id