NCT04613310: RaDiCo

PCR and Rapid Diagnostic Test on Saliva and Nasopharyngeal Swabs for the Detection of SARS-CoV-2 (COVID-19)

Completed NA Last updated 6 October 2025

What this trial tests

NA trial testing Rapid Diagnostic Test vs PCR in COVID-19 in 949 participants. Completed in 31 December 2020.

Timeline

25 September 2020

Primary endpoint
31 December 2020

31 December 2020

Quick facts

Lead sponsor	Center for Primary Care and Public Health (Unisante), University of Lausanne, Switzerland
Phase	NA
Status	Completed
Study type	INTERVENTIONAL
Allocation	na
Design	single group
Masking	none
Primary purpose	diagnostic
Enrollment	949
Start date	25 September 2020
Primary completion	31 December 2020
Estimated completion	31 December 2020
Sites	1 location across Switzerland

Drugs / interventions tested

• Rapid Diagnostic Test vs PCR

Conditions studied

• COVID-19 — all drugs for COVID-19 →
• SARS-CoV-2 — all drugs for SARS-CoV-2 →

Sponsor

Center for Primary Care and Public Health (Unisante), University of Lausanne, Switzerland

Who can join

18 and older, any sex, with COVID-19 or SARS-CoV-2. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Recent literature shows that the sensitivity of the PCR tests for the detection of SARS-CoV-2 using saliva samples is close to that using nasopharyngeal swabs. This type of sampling represents a practical advantage since it can be performed by the patient herself/himself and would thus allow to speed up the collection process. It is also less painful and could prevent the rare lesions to the nasal mucosa that can occur when using nasopharyngeal swabs.

Rapid Diagnostic Tests for the detection of SARS-CoV-2 antigens have been developed using nasophayngeal swabs and have shown very high sensitivity against PCR, ranging from 93% to 98% when based on laboratory validation, 80% when based on clinical validation.This method offers the considerable advantage to inform the patient of the test result on site, and allow the provision of appropriate recommendations on the spot of testing. The studies performed so far have been conducted using nasopharyngeal samples only. There are no data with saliva yet. It is expected that the RDT would also work on the saliva. Even if slightly less sensitive due to the fact that it detects antigens and not multiplied RNA as PCR does, RDT on saliva could better serve the public health goal to test widely and quickly and have ultimately more COVID cases detected and isolated, and hence reduced transmission.

To investigate the case detection rates of both PCR on saliva and nasopharynx and RDT on nasopharynx and saliva, the patient will be taken four samples, two swabs on saliva, one for RDT and one for PCR, and two swabs on nasopharynx, one for RDT and one for PCR. Patients who have at least one of the common symptoms and who consent to such a procedure will be recruited to compare the four results. The primary objective is to compare the case detection rates for SARS-CoV-2 of the four testing methods (two sampling types and two test types).

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

1. Antigen rapid tests, nasopharyngeal PCR and saliva PCR to detect SARS-CoV-2: A prospective comparative clinical trial.
   Schwob JM, Miauton A, Petrovic D, Perdrix J, et al · · 2023 · cited 38× · PMID 36827328 · DOI 10.1371/journal.pone.0282150
2. Antigen rapid tests, nasopharyngeal PCR and saliva PCR to detect SARS-CoV-2: a prospective comparative clinical trial
   Schwob JM, Miauton A, Petrovic D, Perdrix J, et al · · 2020 · cited 6× · DOI 10.1101/2020.11.23.20237057