Evidence supports COVID-19 hearing loss link, say Manchester BRC researchers
Hearing loss and other auditory problems are associated with COVID-19, according to a systematic review of existing research evidence led by NIHR Manchester Biomedical Research Centre (BRC) and University of Manchester scientists.
Professor Kevin Munro, Professor of Audiology at The University of Manchester and Manchester BRC Hearing Health Lead and PhD researcher Ibrahim Almufarrij – who followed up their review which was originally carried out a year ago – found 56 studies that identified an association between COVID-19 and auditory and vestibular problems.
In their Manchester BRC-funded study, they pooled data from 24 of the studies to estimate that the prevalence of hearing loss was 7.6 per cent, tinnitus was 14.8 per cent and vertigo was 7.2 per cent.
The team described the quality of the studies as ‘fair’, as their data primarily used self-reported questionnaires or medical records to obtain COVID-19 related symptoms, rather than the more scientifically reliable hearing tests.
Their findings have been published in the International Journal of audiology.
Kevin Munro, who is also an honorary Consultant Clinical Scientist at Manchester University NHS Foundation Trust said: “There is an urgent need for a carefully conducted clinical and diagnostic study to understand the long-term effects of COVID-19 on the auditory system.
“It is also well-known that viruses such as measles, mumps and meningitis can cause hearing loss; little is understood about the auditory effects of the virus that causes COVID-19.”
“Though this review provides further evidence for an association, the studies we looked at were of varying quality so more work needs to be done.”
Ibrahim Almufarrij said: “Though the evidence is of varying quality, more and more studies are being carried out so the evidence base is growing. What we really need are studies that compare COVID-19 cases with controls, such as patients admitted to hospital with other health conditions.
“Though caution needs to be taken, we hope this study will add to the weight of scientific evidence that there is a strong association between COVID-19 and hearing problems.”
Professor Munro added: “Over the last few months I have received numerous emails from people who reported a change in their hearing, or tinnitus after having COVID-19.
“While this is alarming, caution is required as it is unclear if changes to hearing are directly attributed to COVID-19 or to other factors, such as treatments to deliver urgent care.”
A recent study led by Professor Munro, suggested that more than 13 per cent of patients who were discharged from a hospital reported a change in their hearing. He is currently leading a year-long UK study to investigate the possible long-term impact of COVID-19 on hearing among people who have been previously treated in hospital for the virus.
His team hopes to accurately estimate the number and severity of COVID-19 related hearing disorders in the UK, and discover what parts of the auditory system might be affected.
They will also explore the association between these and other factors such as lifestyle, the presence of one or more additional conditions and critical care interventions.