Many people who develop serious complications from a COVID-19 infection do not experience the symptoms most commonly associated with COVID-19 – cough, shortness of breath, and a sore throat.
This is a warning from Dr Adri Kok, a specialist physician and president of both the International Society for Internal Medicine and the Faculty of Consulting Physicians of South Africa.
Kok said as medical understanding of COVID-19 develops globally, studies are increasingly indicating that the condition can present in widely diverse ways.
“In addition to asymptomatic carriers of the virus, some patients do not exhibit the respiratory symptoms that are most typical of COVID-19, and yet they develop sudden and potentially life-threatening complications arising as a result of the viral infection,” said Kok.
She said in some cases the first sign of a COVID-19 infection is a stroke, heart attack, or organ failure.
“As more studies become available, we are realising that COVID-19 is an extremely varied and unpredictable condition, and there are reports of even young people suffering a stroke,” said Kok.
“Although this virus primarily affects the upper airway and then the lungs due to droplet spread, COVID-19 may set in motion a series of reactions in the body, which may attack the small blood vessels that are crucial to the functioning of other organs including the heart, kidneys, and brain,” she said.
Sometimes, the body has an overzealous reaction to an infection, known as a “cytokine storm”, which can lead to serious complications.
Cytokines are proteins that the body releases to communicate with various cells to co-ordinate bodily responses. This happens when the immune system stimulates inflammation to fight infection, or clotting to help repair damaged tissues.
“It has been suggested that in some COVID-19 patients who progress to a more advanced stage of the illness, a cytokine storm causes a physiological change in the pneumocytes of the lungs,” said Kok.
“This then has a pro-thrombotic or clot-causing effect, potentially leading to abnormal clotting in small blood vessels. This blood clotting is known as thrombosis.”
Apart from stroke, COVID-19 positive patients can also present with cardiovascular damage such as acute ischaemic heart disease or pulmonary embolism.
In addition, it has been observed that COVID-19 can significantly deplete blood oxygen levels even though the patient may not initially feel symptoms of respiratory distress, which is known as ‘silent hypoxia’.
By the time people seek medical assistance, their condition may already be serious, with a low oxygen concentration recorded.
In Netcare hospitals, emergency admissions are cared for in ‘yellow zone’ wards designated for “persons under investigation”.
In these wards, doctors and nursing staff are able to provide the appropriate levels of care pending the result of their COVID-19 test.
Kok said that in addition to COVID-19 testing, a D-dimer test, which indicates clotting, must be performed and the blood oxygen level of emergency patients must be monitored.
“These tests help us to detect the severity of the patient’s condition, particularly if they test positive for COVID-19. Supplemental oxygen and blood-thinning medication, as appropriate, can help to restore blood oxygen and counteract the abnormal clotting effect,” she said.
She said if someone develops a new symptom, no matter whether it is a symptom commonly associated with COVID-19 or not, it is safer not to ignore it.
“From what we know of COVID-19 so far, better outcomes for many health conditions are usually achieved with early treatment,” she said.