Long Covid: What happens when coronavirus lingers?
As the Covid-19 pandemic rolls on, researchers are beginning to understand more about the long-term effects of the illness. Should we be worried?
Evidence is mounting the impact of having Covid can persist into a condition known as long Covid, where symptoms remain or develop later, usually from around four weeks after the initial infection.
Long Covid is what is considered prolonged post-viral syndrome, infectious diseases physician Dr Nick Coatsworth told House of Wellness radio.
“Before the pandemic I would probably see at least one patient per week with what we would call prolonged post-viral sydnrome,” Dr Coatsworth says.
“It’s characterised by you get a virus – it’s mild – it doesn’t put you in hospital, but then you find you get these long symptoms that aren’t really commensurate with the severity of your initial disease.
“The most common symptom we get in these post-viral syndromes is fatigue.
“Long Covid seems also to have sensations of breathlessness, chest pain and there’s a long list after that, but they’d be the top three.”
Other symptoms of long Covid may include memory and concentration problems, taste and smell changes, headaches, persistent cough, sleep problems, and joint and muscle pain.
Long Covid can affect anyone, irrespective of severity of the initial illness, but scientists have identified factors including those with a higher viral load and Type 2 diabetes may increase risk of it developing, while another study suggested genes may also play a role.
Under its clinical case definition of post Covid-19, the World Health Organisation states symptoms can also relapse over time.
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What is the impact of long Covid?
Australian researchers were part of an international review of 57 studies encompassing more than 250,000 people who had Covid.
More than half experienced issues six months later.
And women appear more likely to develop long Covid than men.
The most common symptoms were functional mobility impairments, pulmonary abnormalities, and mental health disorders.
General issues included chest imaging problems, difficulty concentrating, generalised anxiety disorder, general functional impairments, and fatigue or muscle weakness.
Study co-author Dr Govinda Poudel, from ACU’s Mary MacKillop Institute for Health Research, says the majority of participants in the study had been in hospital.
Dr Poudel says while some patterns are emerging, more research is needed to confirm how long effects will last and whether they are different in adults and children.
The Murdoch Children’s Research Institute has reiterated the need for more research in this area, as much is still not well understood.
However, some research suggests children between the ages of 0 to 5 are at greatest risk of developing respiratory symptoms, while kids aged 11 to 16 are more prone to developing long Covid neurological and psychological conditions.
What else do we know about long Covid?
As research into long Covid continues, studies have found it may also impact:
Heart
Some people may experience lingering post-Covid issues such as palpitations, dizziness, chest pain and shortness of breath, which may be a result of heart problems.
Having Covid also increased the risk of cardiovascular diagnoses overall as well as an 81 per cent increase in the chance of being diagnosed with diabetes.
Brain and nerve function
A UK study has found an increased risk in some neurological and psychiatric conditions such as dementia, psychosis and seizures for up to two years post-Covid.
Another US study found the immune response triggered by Covid could damage the brain’s blood vessels and lead to short and long-term neurological symptoms.
The central nervous system.
A large UK study found significant long-term effects post-Covid in those whose original cases were mild, including changes in parts of the brain that affect memory and smell, and tissue damage in regions linked to smell.
The vagus nerve.
A Spanish study investigated links between Covid and the vagus nerve, which regulates organ function and found two-thirds had at least one symptom suggestive of vagus nerve dysfunction.
These can include voice problems, difficulty swallowing, dizziness, high heart rate, low blood pressure and diarrhoea.
Gut microbiota.
Chinese University of Hong Kong research has found the make-up of our gut microbiome may be linked to the risk of developing long Covid months after initial infection.
Our gut biome consists of trillions of bacteria, fungi, and other microbes that inhabit the digestive tract.
The study found that after six months, the gut microbiome of those with long Covid differed from that of Covid patients without long Covid and those who hadn’t had Covid.
Digestion
Changes in the gut can lead to potential problems like diarrhoea and stomach pain, meaning Covid has entered the gastrointestinal cells causing direct damage.
Patients who experienced severe Covid-19 are said to be at particularly higher risk of developing gastrointestinal difficulties following infection.
Hair loss
Another potential post-infection impact of Covid can be hair loss, which may occur around three months later.
Though not expected to be permanent, this is thought to occur as a direct result of physical stress placed on the body during its fight against the virus.
Physical stamina
Healthy young people may have increased cholesterol, higher BMI and reduced physical stamina post-Covid according to a Swiss study, making them more susceptible to metabolic disorders and cardiovascular issues in the long term.
Sleep
Sometimes dubbed “coronasomnia”, difficulties sleeping is a commonly reported long-term complication of Covid.
Research suggests sleep difficulties can persist for more than 30 days after a positive Covid test and may lead to unwanted health effects.
Another study found patients experienced a general decrease in total sleep and deep sleep after contracting Covid-19.
Ears
A systematic review of research by the University of Manchester and NIHR Manchester Biomedical Research Centre (BRC) scientists found Covid-19 may lead to auditory effects.
Covid survivors may experience tinnitus according to a US survey, with patients reporting symptoms for an average of 93 days.
Libido
UK research found sexual dysfunction to be one of many long Covid symptoms, namely a loss of libido.
An Italian study found men may come across difficulties such as erectile dysfunction.
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What can we do about long Covid?
The best way we can minimise our risk of long Covid is to get vaccinated, say the experts.
Associate Professor Paddy Ssentongo from Penn State College of Medicine Department of Public Health Sciences says the most effective way to prevent long Covid is to avoid infection.
“This can be accomplished through proven public health strategies, particularly vaccination,” Assoc Prof Ssentongo says.
Dr Poudel says while there is no empirical data yet, if infection does occur, vaccination may also help reduce the likelihood of long Covid developing, especially if it mainly emerges after serious cases.
“Vaccination reduces the severity of Covid, so it probably helps reduce the chances of long Covid,” he says.
Those experiencing post-Covid symptoms can develop a personal medical management plan from a healthcare provider to monitor and improve symptoms.
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For more expert diet and healthy living advice, tune into House of Wellness radio, Sunday mornings at 8am on Nine Radio.
Written by Cheryl Critchley. Updated by Melissa Hong, November 2022.
