Long COVID a 'whole-body disease,' with some patients experiencing loss of taste and smell for months: expert

Long-term COVID not fully understood, feds warn Canada's chief science advisor Mona Nemer warned that many long-term effects of COVID-19 aren't fully understood.

When Julie Wright joined her family for breakfast on Christmas morning, her meal looked identical to what she ate exactly one year ago. The only difference now was that she couldn’t taste her food.

“I can tell the odd time [whether] something is supposed to be sweet, sour, salty, spicy, but cannot tell you what I'm tasting,” she wrote in an email to CTVNews.ca last week. “Some things just have zero taste at all … imagine not tasting ice cream anymore, [or] that first sip of morning coffee?”

The 40-year-old mother from Newcastle, Ont., began to lose her sense of taste a few months after contracting COVID-19 in December 2021. At that point, Wright had received two doses of the COVID-19 vaccine, she said.

After speaking with her doctor, she was diagnosed with long COVID and eventually referred to a clinic in Toronto. Wright is one of dozens of Canadians who reached out to CTVNews.ca to describe their symptoms while suffering from long COVID. The emailed responses have not all been independently verified.

Also known as the post COVID-19 condition, the World Health Organization (WHO) defines long COVID as the “continuation or development of new symptoms three months after the initial SARS-CoV-2 infection.” Symptoms must persist for at least two months and cannot be attributed to other causes.

More than 200 symptoms have been associated with long COVID, and not everyone who develops the condition will experience the same symptoms. According to the Public Health Agency of Canada (PHAC), common symptoms include fatigue, memory problems and shortness of breath, although the loss of taste and smell have also been reported among those with long COVID, said Dr. Kieran Quinn, a clinician scientist at the University of Toronto and Sinai Health System.

There are several working theories on how long COVID affects the body, Quinn said, one of which points to unregulated inflammation that may take place following a COVID-19 infection. This can cause damage to cells in different parts of the body, such as organs.

“If you get damage in your brain and your memory centres, then you might have memory problems that might be described as brain fog, for example,” Quinn told CTVNews.ca in a telephone interview on Wednesday.

It’s also possible for this inflammation to damage nerves that are associated with a person’s ability to taste and smell. Research on how COVID-19 affects a person’s ability to taste is still limited. According to one study published in July 2022, impaired taste may be the result of SARS-CoV-2 binding to receptors in the salivary glands or mucosal cells in the mouth, which could lead to inflammation and less taste bud sensitivity.

Inflammation can also harm the nerves that transmit information from the nose to the brain. A recent study conducted by scientists in the United States discovered that those suffering from a persistent loss of smell after contracting COVID-19 experienced inflammation in the tissue in the nose, where smell nerve cells are located.

As a result, some may be left without the ability to smell anything, a condition called anosmia. Others may experience parosmia, a distorted sense of smell that can make otherwise normal odours smell unpleasant. The scents are often described as smelling burned, rotten or chemical. The condition may also affect a person’s ability to eat certain foods by triggering nausea.

There is no known medication or treatment to specifically address a loss of smell or taste induced by COVID-19, Quinn said, although data from researchers in California shows patients may soon see some relief.

LOSS OF TASTE OR SMELL LASTS MONTHS FOR SOME

Sylvie Hanes developed parosmia after contracting COVID-19 for the second time in April 2022. By then, Hanes said she had received four doses of the coronavirus vaccine.

“[My doctor] said there's really nothing you can do about it except to wait until your body reacts the right way,” Hanes told CTVNews.ca in a telephone interview on Wednesday.

The 62-year-old from Ottawa said the smell of meats such as beef and pork while cooking would give her instant nausea, preventing her from eating these foods.

“It’s been eight months without beef, pork [or] sausage,” she said. “Anything that has meat smell, I have to stay away from … just thinking about it makes me sick.”

As a result, she would avoid going to restaurants or friends’ houses where meat was being served. She also avoids purchasing certain meat products while grocery shopping, she said. While the nausea she experiences isn’t as violent as it was a few months ago, Hanes said it still exists today. However, the nausea does not apply to other foods and her sense of taste is not impaired, she said.

Changes in a person’s sense of taste and smell are common among those with COVID-19, with an average of 40 to 50 per cent of patients reporting these symptoms around the world.

Data shows most people will eventually recover. According to one analysis involving 267 adult patients who lost their sense of taste and/or smell after a COVID-19 infection, most people either completely or partially recovered about two years after their infection. However, 7.5 per cent had still not regained their ability to taste and/or smell two years after contracting COVID-19.

COVID-19 A ‘WHOLE-BODY DISEASE’: EXPERT

Yet another symptom experienced by some long COVID patients is tinnitus, characterized by a ringing sound or other noise in the ear. Inflammation of the nerves in the inner ear that connect to auditory centres in the brain can result in a noise not caused by an external sound.

“That ringing is simply a sign that the nerve is not working properly,” Quinn said.

In observing these impacts on basic human senses, there appears to be a connection between COVID-19 and the nervous system, Quinn said. While SARS-CoV-2 primarily infects the lungs, the ACE-2 receptor used by the virus to enter cells can appear in multiple tissues and organ systems, he said.

“That’s why we think that long COVID is a systemic illness, it’s not just an illness of the lungs,” said Quinn. “It’s definitely a whole-body disease.”

Nicole Rogers caught COVID-19 in March 2020. Despite having a mild infection, she said she later developed long COVID, experiencing symptoms such as extreme fatigue and tinnitus. In August 2020, she went to a hearing clinic and was eventually fitted with a hearing aid.

“They said I have mild hearing loss [in] my left ear,” she told CTVNews.ca in a telephone interview on Wednesday. “It cuts the tinnitus by about half and makes it tolerable.”

While the condition is “inconvenient,” it’s not as debilitating as the chronic fatigue syndrome (CFS) and cognitive issues she has since developed, said the 50-year-old from Langley, B.C. Rogers said she is currently on permanent disability leave after a 23-year career as a teacher.

“I was extremely active, never sat down, and now I’m shopping for a wheelchair,” she said. “Most days I can’t leave my house, I’m so dizzy … I can’t even stand in the shower anymore.”

In November 2020, Rogers was admitted to a long COVID clinic in Vancouver but has since been discharged. She has one dose of the COVID-19 vaccine, and has been taking low-dose naltrexone to manage her CFS, she said.

“It’s an invisible illness,” she said.

‘NOBODY SEEMS TO KNOW THE ANSWERS’

Based on data released by Statistics Canada in October, about 15 per cent of Canadian adults who had COVID-19 said they still experienced symptoms at least three months after their infection. Despite this, there is currently no way of clearly diagnosing or treating long COVID, according to the PHAC.

The wide range of symptoms associated with long COVID can make diagnosing the condition “a major challenge” for health-care providers and patients, Quinn said. Symptoms are often not exclusive to long COVID, but associated with other conditions, too. This can lead to some variation in terms of how physicians determine whether someone has long COVID, he said.

“Information gaps are a huge problem for us … nobody truly knows what causes long COVID,” Quinn said. “As health-care practitioners, we have to make the best decisions that we can for our patients operating on imperfect evidence.”

In the meantime, treatment continues to focus on helping patients manage symptoms, Quinn said.

After being admitted to the long COVID clinic in June 2022, Wright worked with various specialists, including a speech therapist and dietician, to manage her symptoms, which also included memory loss, difficulty concentrating and extreme fatigue. Along with long COVID, Wright has a heart defect known as bicuspid aortic valve and takes medication to manage her cholesterol.

By the end of September, she was discharged despite continuing to experience symptoms, she said.

“Nobody seems to know the answers,” she told CTVNews.ca in a telephone interview on Wednesday. “It’s heartbreaking.”

The lack of information that continues to surround the condition is the hardest part of living with long COVID, Wright said.

“You just want to know it’s going to end or it’s going to get better,” she said. “That’s what scares me the most. I can handle the not having taste, I can handle the not having smell … It’s the not knowing that really drives me crazy.”

However, online communities supporting those with long COVID are a useful resource, said Wright, Hanes and Rogers.

Facebook groups for those with specific conditions such as parosmia, or long COVID in general, have helped all three women cope with their symptoms, they said.

The COVID Long-Haulers Support Group Canada was founded in 2020 by Susie Goulding, and currently has more than 18,000 members. The group allows Canadians with long COVID to connect with others who also have the condition, in order to better understand it and spread awareness, she said.

“A lot of people don’t get the support that they need from their families, friends and the medical community, and it’s like an ostracization,” she told CTVNews.ca in a telephone interview on Thursday. “We’re a lifeline of support for people.”

The group allows members to share their advice and acts as a reminder that anyone living with long COVID is not alone, said Goulding, who has the post COVID-19 condition herself. The group also connects those who have lived experience with long-COVID researchers for ongoing studies.

“The more that we collaborate and have our voices heard, that’s what’s important to create meaningful research,” she said.

With files from CTVNews.ca writer Alexandra Mae Jones, CNN