Investigating the persistence of SARS-CoV-2 in the olfactory mucosa of patients with prolonged COVID-19 symptoms

Investigation of the Persistence of SARS-CoV-2 in the Olfactory Mucosa of Patients With Prolonged Symptoms of COVID-19 With Neurocognitive Complaints: a Prospective Cross-sectional Multicenter Case / Control Study (NEUROCOVID)

Not applicable Interventional Fondation Ophtalmologique Adolphe de Rothschild · NCT05220241

This study is testing whether the virus that causes COVID-19 sticks around in the nose of people who have had long-lasting symptoms, to see how it might relate to problems with thinking and senses.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment50 (estimated)
Ages18 Years to 60 Years
SexAll
SponsorFondation Ophtalmologique Adolphe de Rothschild Research network
Locations2 sites (Paris and 1 other locations)
Trial IDNCT05220241 on ClinicalTrials.gov

What this trial studies

This study aims to compare the presence of SARS-CoV-2 viral RNA in the olfactory mucosa of patients experiencing prolonged symptoms of COVID-19 against a control group. It will assess the correlation between viral persistence and neurological symptoms, including cognitive disorders and sensory disturbances. Participants will undergo nasopharyngeal swabs for RT-PCR testing to detect the virus. The study focuses on individuals aged 18 to 60 who have had documented COVID-19 symptoms lasting beyond four weeks.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 to 60 who have experienced COVID-19 symptoms for more than four weeks and have documented evidence of the virus.

Not a fit: Patients with COVID-19 symptoms explained by other diagnoses or those outside the specified age range may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance understanding of long COVID and lead to targeted treatments for patients suffering from prolonged symptoms.

How similar studies have performed: While some studies have explored viral persistence in immunocompromised individuals, this investigation into long COVID symptoms and viral presence is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Common to cases and controls:

* Age ≥ 18 years old and \<60 years old
* Good oral and written command of French
* Level of education ≥ 7 years of schooling
* Initial episode of COVID-19 within 2 to 12 months
* Symptomatic initial episode of COVID-19
* Initial symptoms not explained by another diagnosis
* Initial episode documented by RT-PCR positive for SARS-CoV-2 and / or positive antigen test and / or positive serology (in the absence of vaccination)
* Express consent to participate in the study
* Affiliate or beneficiary of a social security scheme

Case group:

* Presence of at least one of the initial symptoms beyond 4 weeks following the onset of the acute phase of the disease
* Prolonged symptoms not explained by another diagnosis with no known link to COVID-19
* Neurocognitive complaint (s) previously objectified by a neurologist and after completion of a neuro-psychological assessment
* Impact of neurocognitive disorders on daily life authenticated by a Glasgow outcome scale extended ≤ 7 (see appendix 1)
* Evolution of complaints for 2 to 12 months compared to the date of their first appearance

Exclusion Criteria:

Exclusion criteria common to cases and controls:

* Person benefiting from a legal protection measure
* Pregnant or breastfeeding woman
* At least one neurological pathology among:

  * encephalopathy
  * encephalitis
  * severe neurological form of the initial episode of COVID-19
  * neurodegenerative disease
* History of stroke
* Serious psychiatric history
* Known nasal sinus pathology
* Hemostatic disorder
* Taking aspirin in the 15 days preceding the sample
* Treatment with anticoagulants
* Known allergy to lidocaine

Secondary exclusion criteria for controls:

- Positive SARS-CoV-2 RT-PCR on nasopharyngeal sample on the day of inclusion

Where this trial is running

Paris and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions SARS-CoV-2 InfectionCognitive Disorder
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.