New research suggests that the inner ear is susceptible to infection with SARS-CoV-2, which causes COVID-19.
Covid-19 patients have reported symptoms affecting their ears. These symptoms include complaints about hearing loss, tinnitus (ringing in the ears) and balance problems. Individuals suffering from long-haul Covid-19 also report similar symptoms long after their initial infection. The implication is that the SARS-CoV-2 virus may be able to infect the inner ear.
In a recently published study, Massachusetts Institute of Technology (MIT) and Massachusetts Eye and Ear analyzed cellular models of the human inner ear and adult human inner ear tissue with SARS-CoV-2 infection to discover the effect of SARS-CoV-2 on the inner ear. From MIT News, “The pattern of infection was consistent with the symptoms seen in a study of 10 Covid-19 patients who reported a variety of ear-related symptoms.”
Spread of the Virus
There are several possible vehicles for the virus to enter the ear, including the Eustachian tube (connects your nose to your middle ear space). The virus may also travel from the nose through small openings surrounding the olfactory (sense of smell) nerves, allowing the virus to enter the brain space and infect cranial nerves, including the cranial nerve that connects to the inner ear.
Until More is Known
Unfortunately, the overall percentage of Covid-19 patients who have experienced ear-related issues is not known. This lack of information could be in part be due to the severity of other symptoms. The patient may have initially been unaware of less life-threatening complications along the lines of hearing loss, tinnitus and balance issues. However, these findings do call for paying increased attention to Covid-19 patients who complain of changes to the status of their hearing and balance systems.