A systematic review of 24 studies suggests that COVID-19 is strongly associated with hearing loss and other auditory problems, adding to a growing list of symptoms.
A year now into the pandemic, we've all become familiar with COVID-19 and how it manifests itself. We all know that infection with the coronavirus can cause fever, fatigue, trouble breathing, nausea, vomiting, and even the bizarre loss of taste and smell. In rare cases, some patients have so-called 'COVID toes', an inflammatory rash that causes toes to swell, burn and itch, and even turn them red or purple. Others get blood clots and dementia-like symptoms, such as confusion, headaches, or dizziness. Now, scientists are prepared to add another odd symptom to the list -- hearing loss.
The team of researchers at the University of Manchester, led by Professor Kevin Munro, the Director of the Manchester Centre for Audiology and Deafness (ManCAD), pooled data from more than two dozen studies that identified an association between COVID-19 and auditory and vestibular problems.
According to the results, the prevalence of hearing loss was 7.6%, tinnitus was 14.8% and vertigo was 7.2%.
"We know that some viruses can damage the ear and the virus that causes COVID-19 affects lots of different organs in the body," Munro told ZME Science.
"This study is a review of everything that has been published on covid and hearing problems. We had to screen around 1,600 articles to find the 50-60 that were relevant. What we have done is to provide the best estimate of hearing problems so far," the researcher added.
These findings aren't definitive and the associations are only correlative, but they are worrisome enough to warrant urgent investigation. It's well established that other viruses such as measles, mumps, and meningitis can cause hearing loss, so it's no stretch of the imagination that the same may be the case for SARS-CoV-2.
"Viruses can damage the delicate sensory cells within the ear or damage the hearing nerve. We don’t yet know why people with confirmed COVID are reporting hearing problems," Munro said.
This week, news broke out that Kent Taylor, Texas Roadhouse CEO, died by suicide after struggling with post-COVID-19 symptoms, including severe tinnitus. According to those close to him, the billionaire suffered greatly from ringing and other noises in his ears. His most recent days were unbearable.
It's still not clear whether the hearing issues are due to the COVID infection or to other factors, such as treatments received at the hospital or intensive care unit. Munro is now in the midst of conducting a year-long study in the UK that aims to infer any causal relationship between COVID-19 and hearing disorders. In the process, the researchers hope to learn how long it takes for the hearing issues to subside or whether or not there's any permanent damage. Another study in which Munro was involved suggested that more than 13% of patients who were discharged from a hospital reported a change in their hearing.
"We know that some people have already recovered but it is also possible that for others the changes to their hearing is permanent," Munro said.
The findings appeared in the International Journal of Audiology.