Some COVID-19 patients who recovered from the virus said that they regain their sense of smell but only to whiff foul, unpleasant fishy, sulphur, and burning odors.

Researchers continue to study the lasting effect of COVID-19 on those who tested positive for the virus.

It has been well-known and established in different studies that those who recovered from the virus continue to experience its symptoms even months afterward.

Read also: CDC Issues Vaccination Guidance for Persons With Underlying Conditions 

Long-Term Effect of COVID-19 

New reports reiterate that the so-called "long haulers" are experiencing a distorted sense of smell, catching odd, unpleasant fishy, sulphur, and burning odors while researchers continue to study lasting and long-term effects after getting infected for COVID-19. 

According to Sky News, Professor Nirmal Kumar, consultant ENT surgeon and president of ENT UK, attributed the warped sense of smell to parosmia and called it "very strange and very unique."

The National Institutes of Health also said parosmia signals an altered "perception of odors," "or when something that normally smells pleasant now smells foul."

Meanwhile, the U.S. Centers for Disease Control and Prevention has still to include parosmia on its list. Even though reports of coronavirus long haulers experiencing foul odors cropped up earlier this year. The agency said that their list does not include all possible symptoms. 

On its website, the U.S. CDC stated, "CDC will continue to update this list as we learn more about COVID-19."

Additionally, one expert previously elaborated on the effect of the virus on the sense of smell in the context of viral pathogens to Fox News.

Read also: Dr. Fauci Admits Experiencing Side Effects After Getting COVID-19 Vaccine 

Distorted Sense of Smell Explained

Dr. Susan Shin, an assistant professor of neurology at Mount Sinai Hospital, said, "There are two sensory systems in our nose. We are able to detect pleasant fragrances by way of the olfactory nerve, whereas dangerous, toxic smells are detected by the trigeminal nerve."

She also added, "The trigeminal nerve is likely more resilient to effects of a viral pathogen compared to the olfactory nerve because we need it to detect dangers in our environment, such as smelling smoke from a fire."

According to a published report in Fox News, Kumar said that thousands of patients across the UK are already treated for their loss of sense of smell that they associated with anosmia.

However, some are now experiencing the largely unpleasant odors associated with parosmia. Kumar explained that the patients' distorted smell stems from "olfactory hallucinations."

Kumar told Fox News "This virus has an affinity for the nerves in the head and in particular, the nerve that controls the sense of smell. But it probably affects other nerves too and it affects, we think, neurotransmitters - the mechanisms that send messages to the brain."