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Anosmia and Covid-19

SARS-CoV-2 Infection/Covid-19 and Anosmia - Prevalence Study, Molecular Analysis and Clinical Trial

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05246059
Acronym
COVANOS
Enrollment
63
Registered
2022-02-18
Start date
2020-06-03
Completion date
2021-08-08
Last updated
2022-02-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Anosmia, SARS CoV 2 Infection

Brief summary

Our study aims to determine the prevalence of anosmia in patients SARS-Cov-2/Covid-19 infection (both by symptom reporting and smell testing), the efficacy of early olfactory training for the treatment of anosmia caused by infection and the long-term impact of smell dysfunction with a one-year follow-up.

Detailed description

Around 10-15% of patients with acquired anosmia have Post Viral Olfactory Loss (PVOL). Coronaviruses are a known cause for anosmia. At the onset of the COVID-19 pandemic, reports from China, South Korea, US and Europe suggest that a significant proportion of COVID-19 patients describe a loss of smell and taste as the only symptoms or as part of mild flu-like symptoms. It is now well-established that these symptoms are important components of the COVID-19 sequelae with persistent dysfunction described in a subset of individuals. For this study, individuals, mainly comprising mainly healthcare workers in the UK, with persistent and sudden loss of sense of smell (at least 4 weeks) were recruited to ascertain the prevalence of COVID-19 associated smell dysfunction. A positive COVID-19 test was not a requirement for participation if not readily available nor accessible, however, information regarding COVID-19 antigen and antibody testing was collected post-hoc from those for who data are readily available. All participants (n=227) underwent initial psychophysical smell testing using the Brief Smell Identification Test (BSIT), gustatory testing using Taste Strips and completed the Smell Qx questionnaire. This questionnaire collected relevant demographic information, medical history, details of COVID-19 symptoms experienced, as well as information on olfactory and gustatory function, including those related to quality-of-life. Participants, who scored 8 or below on the BSIT (indicative of semi-quantitative smell loss) were further invited to participate in the early olfactory training randomized controlled trial. Participants were randomized to undergo either 12 weeks of olfactory training or receive safety information. At the end of the 12-weeks, participants completed a follow-up BSIT and survey. All participants enrolled at baseline within the eligible timeframe, for whom a valid email address was available, were further invited to participate in 1 year follow-up assessments. This included all participants irrespective of baseline BSIT result and RCT participation. The follow-up included a final electronic survey and BSIT. In addition to questions related to their sense of smell, which were identical to those in the baseline and 12-week follow-up surveys, participants were also asked about any symptoms of long-Covid.

Interventions

Sniffin' Sticks (Duft-Quartett, Burghart Messtechnik, GmbH, Germany)

Sponsors

University College, London
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Confirmed (positive laboratory antigen test) or suspected COVID-19 infection * Sudden onset of smell loss * Smell loss of at least 4 weeks * Reduced smell function through psycho-physical testing (Brief Smell Identification Test score of 8 or less)

Exclusion criteria

\-

Design outcomes

Primary

MeasureTime frameDescription
Brief Smell Identification Test (BSIT)12-weeksThe absolute difference between the intervention and control arms in BSIT score smell improvement, measured as a change from baseline at 12-weeks.

Secondary

MeasureTime frameDescription
Quality of Life Score12-weeksWithin subject changes to scoring of questionnaire quality of life items at 12-weeks compared to baseline
Compliance (anecdotal)12-weeksParticipant compliance to olfactory training through anecdotal reporting
Safety (anecdotal)12-weeksSafety of the use of Sniffin' Sticks through anecdotal reporting

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026