From the earliest days of the COVID-19 pandemic, scientists have raised concerns about the potential for long-term health problems linked to SARS-CoV-2 and warned repeated infections are likely to increase the risk.
An association between COVID and
cardiovascular disease emerged quickly.
And now — almost exactly four years since the first case was discovered in Wuhan —
a growing body of scientific research is cautiously linking the inflammation caused by a COVID infection to diseases like Alzheimer's and Parkinson's as well as autoimmune conditions from bowel disease to rheumatoid arthritis.
..."Any time you see olfactory impairment it tells you that there's going to be neurological impact," he says. "Loss of smell is a cardinal, pre-clinical symptom of Parkinson's disease and it's been implicated in Alzheimer's disease as well."
...The fact that COVID patients reported loss of smell not only during the active phase of the disease, but as a persistent symptom, suggested to Barnham that longer-term health consequences were likely.
Loss of smell is associated with loss of brain volume.
...A Danish study, for example, published in 2022, compared just under 1 million participants who took COVID-19 tests and found
the 43,375 who tested positive for the virus had a substantially increased risk of Alzheimer's disease (3.5 times), Parkinson's disease (2.7 times) and ischaemic stroke (2.7 times) and up to 4.8 times the risk of bleeding in the brain.
...If COVID is confirmed to trigger diseases including Parkinson's — which can take up to 30 years to manifest symptoms and is now diagnosed at an average age of 61 —
then someone who contracts COVID as a child or adolescent may be diagnosed in their 40s, generating a significant disease burden. Parkinson's would cease to be only a disease of the elderly, he says.
Genes, environment and lifestyle are some of the risk factors for serious diseases like Parkinson's and Alzheimer's. This is why scientists believe COVID-19 infection should be added to the list, writes Catherine Taylor.
www.abc.net.au