A "fit and well" man developed permanent hearing loss after contracting coronavirus, with researchers saying the worrying new side effect needs significant investigating.
The case report, published in the British Medical Journal, revealed how the 45-year-old British man had been in good shape and only suffered from asthma prior to testing positive for Covid-19.
On day 10 of the diagnosis he was admitted to hospital where he was placed on a ventilator after having trouble breathing.
He developed several medical complications including pneumonia and blood clots, with doctors treating him with steroids, a plasma infusion and the drug remdesivir – the same medication used to treat Donald Trump when he had coronavirus.
The man recovered and was taken off his ventilator, however, then discovered he could not hear out of his left ear.
Testing confirmed he had gone permanently deaf in his left ear despite previously having no hearing issues, with doctors confirming the loss was not the result of any inflammation.
The case report concludes the hearing loss was likely due to Covid-19 and recommends more research be done into this potential side effect.
"Despite the low numbers of studies, it is significant to consider the possibility of a relationship between Covid-19 and SSNHL (sudden sensorineural hearing loss)," the report stated.
"Hearing loss and tinnitus are symptoms that have been seen in patients with both Covid-19 and influenza virus but have not been highlighted," the BMJ report also added.
A study published in July by JAMA Otolaryngology found traces of coronavirus in the ears of two out of three people who had died from the virus.
Hearing loss isn't the only worrying side effect that's been reported by coronavirus patients.
A research paper by the Florey Institute published last month found there was growing evidence that coronavirus was getting into the brain raising fears there could be a spike in Parkinson's disease in the years to come.
Florey researcher Leah Beauchamp said neurological symptoms also came with the Spanish flu 100 years ago.
Five years later the world saw a two to three-fold increase in the incidence of Parkinson's worldwide.
People diagnosed with coronavirus have also reported a loss of their sense of smell or taste, with some still yet to recover these senses despite it being months since they recovered.
Back in August an online survey of 1500 coronavirus survivors revealed more than a quarter of them were experiencing hair loss.
Grace Dudley said her hair had fallen out "in clumps" after she contracted Covid-19 and a specialist has since told her she "was going to lose most if not all of it".