Global Health Asia-Pacific June 2021 | Page 34

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There ’ s a huge “ subset of individuals who do not have any underlying conditions that can explain the symptoms developed after the infection and now persistent . This is what I call long COVID ” due to the fatigue and struggled to stay hydrated as I didn ’ t have the energy to eat or drink .”
Patients with dysautonomia get dizzy and their hearts start racing for no reason every time they stand up , or they can develop uncontrollable stomach cramps and diarrhoea .
Some of these symptoms can be traced back to diseases that predate COVID-19 infection ( like diabetes and hypertension ) or specific organ damage directly caused by the virus , such as lung or kidney dysfunctions , explained Dr Nath . In most instances , however , no physiological abnormalities can be found to make sense of the new COVID-associated conditions , with batteries of tests coming back negative .
There ’ s a huge “ subset of individuals who do not have any underlying conditions that can explain the symptoms developed after the infection and now persistent ,” he stressed . “ This is what I call long COVID .”
Defining long COVID in such a way is useful for the type of research Dr Nath is setting up . His study is trying to determine whether patients with unexplained long COVID symptoms can offer clues about myalgic encephalomyelitis / chronic fatigue syndrome ( ME / CFS ), a poorly understood medical condition characterised by long-term debilitating fatigue not caused by any recognisable physiological glitch and often associated with viral infections , such as influenza , mononucleosis , and respiratory or gastrointestinal infections .
A significant number of patients with long COVID meet the diagnostic criteria for ME / CFS , including functional impairment , unrefreshing sleep , orthostatic intolerance ( discomfort happening while standing ), and postexertional malaise , or worsening of symptoms after minimal exercise . These similarities offer a promising line of research to crack the code of both long COVID and ME / CFS .
Other experts , however , believe a much broader definition of long COVID is warranted .
Debilitating fatigue is a common problem of long COVID
“ Pragmatically , I think anyone who has any symptom extending beyond six weeks following infection with COVID-19 has long COVID ,” said Professor Gisli Jenkins , a respiratory physician and a lung disease researcher at Imperial College London , in an interview with Global Health Asia-Pacific .
While caring for patients with long COVID , Professor Jenkins observed that fatigue and breathlessness were key symptoms and in some instances was able to associate them with disrupted blood flow or tissue damage in the lungs . He ’ s conducting a study to measure how many of these patients develop long-term lung damage , like scarring , to quantify the scale of the problem and understand which therapeutic approaches should be researched .
“ If you ’ re breathless , there ’ s likely something wrong with your lung function ,” he said . “ It ’ s worth remembering COVID is primarily a disease of the lungs ; it starts in the upper airways , and people are brought into hospital because they have infection and inflammation of the lungs , and so it ’ s not a huge surprise to me that the commonest symptoms are breathlessness and fatigue .”
Though most of Professor Jenkins ’ patients tend to be over 50 and at higher risk of being hospitalised for COVID-19 infection and tissue damage , he has also seen a few younger individuals with mild infections who didn ’ t require hospitalisation but still ended up with long-term lung inflammation and scarring .
Overall , however , preliminary data show that a significant number of patients with long COVID symptoms are much younger than those who are usually treated in hospitals for COVID-19 .
The highest prevalence of long COVID symptoms 12 weeks after infection was found among people aged 25 to 34 years , according to a survey conducted by the UK Office for National Statistics .
A similar trend has been observed by Dr Tae Chung , a neuromuscular physician who has been treating patients with post-COVID dysautonomia at Johns Hopkins in the US since last summer . “ Most of my patients with long COVID are relatively young , in their 30s and 40s , and lots of them even in their 20s , and they have never been hospitalised for COVID-19 ,” he said , noting that they were healthy and athletic before coming down with a condition that made them unable to go to school or work due to tiredness and brain fog .
Dr Chung believes this cohort of patients is affected by postural orthostatic tachycardia syndrome ( POTS ), a form of dysautonomia where the autonomic nervous system that normally regulates involuntary functions like blood pressure and heart rhythm is impaired , thus causing patients to experience lightheadedness , brain fog , and fatigue while standing because of reduced blood flow to the brain .
“ I feel like autonomic dysfunction or POTS is affecting the larger portion of patients with long COVID , but we ’ ll need more research to confirm that ,” suggested Dr Chung , who ’ s a POTS specialist and has
32 JUNE 2021 GlobalHealthAsiaPacific . com