What aftereffects bother people most who were infected by Covid-19 but cured of the disease?
A research paper published in the latest issue of the Korean Journal of Internal Medicine offered some clues to this question. The author is Kim Yun-jeong, a professor of infectious disease at the Catholic University of Korea Incheon St. Mary’s Hospital.
Professor Kim analyzed the so-called long Covid into eight categories – respiratory system, hematology, cardiovascular system, psychiatry, endocrine, kidney, digestive organs, and dermatological complexity. Guidance for U.K. health workers describes long Covid as symptoms that continue for more than 12 weeks after an infection that cannot be explained by another cause.
Long-term aftereffects of virus infection were also reported in the patients of influenza, Severe Acute Respiratory Syndrome (SARS), and Middle East Respiratory Syndrome (MERS).
There were reports on the chronic appearances of fatigue, pain, weakness, depression, and insomnia after being cured of SARS. Some 40 percent of cured SARS patients also reported they experienced chronic fatigue for up to three-and-a-half years of diagnosis.
In the case of Covid-19, most patients led normal lives after being cured, but not a few suffered from its aftereffects for weeks or months. For example, a study has found that 54 percent of 250,000 Covid-19 patients experienced aftereffects at least once within one month, 55 percent between two to five months, and 54 percent after six months or more.
Most commonly continuing aftermaths were “respiratory symptoms,” such as breathing difficulty, decreased athletic ability, and hypoxia. The most frequently reported long-term aftereffect was declining diffusion capacity after recovery from the acute phase.
According to Professor Kim, a U.K. study of 384 Covid-19 patients for two months has found 53 percent complained of difficulty breathing and 34 percent continuous coughing. Besides, 50 percent of 349 patients showed abnormal chest CT scans after six months from complete curing.
Some cases of hematological complications were also reported, although there were not many study results. A study of 163 cured patients showed that blood clots and bleeding occurred in 2.5 percent and 3.7 percent, respectively, on the 30th day of leaving hospitals.
“Cardiovascular aftereffects,” including palpitation, difficulty with breathing, and chest pain, were also reported. According to a study, about 20 percent complained of chest pain during the two-month monitoring of Covid-19 patients. Besides, cardiomyopathy and myocarditis also increased from the pre-pandemic era.
There were also many reports of “psychoneurotic complications,” including chronic weakness, depression, and insomnia. In addition, some patients said they experienced decreased memory and concentration and linguistic problems.
Besides, 56 percent of Covid-19 patients complained of post-traumatic stress disorder (PTSD), depression, anxiety, and insomnia after one month of hospitalization. In a large-scale study of 62,354 patients, 18.1 percent reported the occurrence or recurrence of psychiatric symptoms between 14 and 90 days of diagnosis.
“Kidney complication” was also one of the Covid-19 aftereffects. A report said 20-31 percent of severe Covid-19 patients experienced severe acute kidney damage requiring dialysis. Another report found that 35 percent of patients experienced the lowering of glomerular filtration rate six months after the acute phase, and 13 percent said the rate began to drop anew after showing normalcy during the acute phase.
“Kidney diseases related to Covid-19 can be explained by the deformation of focal segmental glomerulosclerosis (FSGS), acute tube damage, and the degradation of the glomerulus, which appear in response to interferon and cytokine activation,” Kim said. “Few of them require dialysis after leaving hospitals, but we need to keep monitoring whether they restore kidney functions.”
Like other respiratory viruses, Covid-19 is also likely to change microbiomes in intestinal tracts. Studies are currently underway on “complications in digestive organs,” such as irritable bowel syndrome and indigestion.
Nor can “dermatological complications” be ignored. A study of 716 patients showed dermatological complications in 64 percent after the acute phase is over. It took an average of 7.9 days to move from the appearance of upper respiratory tract symptoms to that of dermatological symptoms, with 3 percent experiencing skin rashes for up to six months. Notably, 20 percent of patients experienced hair loss.
“Covid-19’s aftereffects can occur in various organs for a long time,” Professor Kim said. “An increasing number of people are expected to recover from Covid-19 due to the protracted pandemic. Therefore, we need to develop a multidisciplinary treatment system to diagnose and treat long-term aftereffects, directly and indirectly.”