COVID-19 is a novel illness with limited information on the post- COVID-19 symptoms. The aim of the current study was to identify the essential determinates of the different patterns of these symptoms. Most of the studied population had been still complaining of several persistent post-COVID-19 symptoms. The most frequent constitutional and neurological symptoms were myalgia (60.0%), arthralgia (57.2%), restriction of daily activities (57.0%), sleeping troubles (50.9%), and nervousness and hopelessness (53.3%), while the most common respiratory and GIT symptoms were anorexia (42.6%), chest pain (32.6%), gastritis (32.3%), cough (29.3%), and dyspnea (29.1%). The mean total score of these post-COVID-19 symptoms was 13.1 ± 12.6. The main essential determinants of the persistent post-COVID-19 symptoms and symptom score among the included patients were previous seasonal influenza vaccination (P = 0.003) and the need for oxygen therapy (P < 0.001). Moreover, the most frequent pre-existing comorbidities allied with the persistent post-COVID-19 symptoms and symptom score among the study population were hypertension (P = 0.039), followed by chronic pulmonary disorders (P = 0.012), and lastly, the presence of any chronic disorder (P = 0.004). There was a strong positive correlation between the symptom score during the acute attack and post-COVID-19 stage (P < 0.001, r = 0.67). Furthermore, the acute phase score had 83.5% sensitivity and 73.3% specificity for the cutoff point > 18 to predict the occurrence of post-COVID symptoms.
By reviewing available literature, about 87% of those who recovered from COVID-19 infection were still suffering at least one symptom 1 to 2 months after disease onset. A wide spectrum of symptoms was reported including lethargy, breathing difficulty, cough, palpitations/tachycardia, chest pain, sleeping troubles, headache, joint ache, and deterioration of physical and mental well-being [5, 8,9,10,11,12].
On the other hand, an initial report of COVID-19 post-discharge complaints in China summarized that 86.2% of cases were asymptomatic while only 9.1 had cough and 1.5% had breathing difficulty that did not affected neither daily activities nor sleep, while dizziness, headache, and lethargy were not reported by those patients at all [13].
The duration of symptom resolution in included COVID-19 cases appears to be longer than that seen in community-acquired pneumonia caused by bacterial pathogens. Previous studies in patients with community-acquired pneumonia found that 97% of their symptoms recovered by an average of 10 days, while dyspnea resolved after an average of 2 weeks from the onset of the symptom, and lethargy after 3 weeks [14, 15].
It is not yet clearly recognized why some patients have persistent recovery. Long-lasting viremia owing to vague or weak or immunological reaction [16], relapse or re-contamination [17], inflammatory and other immunological responses [18, 19], de-conditioning [20], and psychological elements such as post-trauma stress syndrome may all added [21, 22]. Moreover, severe COVID-19 infections necessitate management in ICU and may lead to persistent post-recovery sequelae including respiratory, physical, mental, and psychological disorders [2, 3]. These complaints are stated to as post-intensive care syndrome (PICS); these sequelae can have persistent implications on the life quality [4]. Patients suffering PICS commonly report higher prevalence of mental and physical disorders, which may often be long-standing [23]. PICS can also cause disability and reasonable pain [24]. According to Murray et al., about half percent of hospitalized patients for COVID-19 will necessitate constant care to ameliorate their long-standing consequences [6].
Post-recovery symptoms may also be predicted from the preceding coronavirus epidemics of severe acute respiratory syndrome. SARS survivors still had long-lasting lethargy, myalgia, weakness, hopelessness, psychological distress, and sleep abnormalities which may overlay with the clinical and sleep topographies of fibromyalgia and chronic fatigue syndrome [25]. Myopathy due to corticosteroid use, muscle degenerative changes, and weakness has similarly been described in ARDS survivors during 1-year follow-up period [26]. Another study on the survivors of SARS confirmed deficits in cardio-respiratory performance in 6-min walking test, abnormalities in the musculo-skeletal performance, and quality of life impairment [27]. A similar image was described subsequently after the H1N1 influenza epidemic in 2009 [28]. Following SARS, some cases suffered a decline in their mental well-being during 1-year follow-up period comprising nervousness, hopelessness, high incidence of posttraumatic stress disorders, and psychosis [29].
Moreover, 10 years following SARS recovery, vulnerability to lung contagions, abnormality in glucose absorption, and elevated levels of phosphatidylinositol persist in comparison with healthy ones [30]. A recent meta-analysis found that 25% of SARS and MERS survivors had diminished lung function, quality of life, and exercise capability at 6 months post-discharge [31]. Similarly, the MERS convalescent cases also reported the ominously lower quality physical health for at least 14 months after the infection start, also survivors who anticipated intensive care unit admittance described an ominously minor inclusive quality of life than those with non-critical disease [32].
In the current study, 29.1% of included cases had breathing difficulty. This may be explained by some persistent fibrotic changes in the lungs of COVID-19 recovered patients following the current management and discharge rules which may disturb their respiratory function [33]. Moreover, patients with severe COVID-19 criteria may progress to acute respiratory distress syndrome (ARDS) and necessitate mechanical ventilation. ARDS may cause indefinite lung damage, contributing to persistent respiratory disorders after convalescence [34]. Amid 33 and 75% of cases with COVID-19 necessitate mechanical ventilation, often for a long period, and there are substantial long-term effects allied with prolonged period of intubation [35, 36]. Those on ventilators are more susceptible to respiratory contagions, which, consecutively, making patients more vulnerable to further risk of irreversible damage of the lung tissue.
There is emergent proof advocating that pulmonary thrombo-embolism is likely an underreported complication allied with COVID-19 that carries actually a major risk of long-standing pulmonary hypertension [37]. Furthermore, prior studies have shown that acute lung injury is allied with pulmonary fibrosis on CT scans and associates with restrictive functional pattern and worse quality of life [38].
Thirty-five percent of cases included in this study had nervousness and hopelessness. Consistently, COVID-19 is linked with a major mental health problem in both the acute stage and the chronic term [39]. Nervousness, hopelessness, post-traumatic stress disorder, and sleeplessness are common behind severe coronavirus contagions [40, 41]. Thirty percent of the initial 153 COVID-19 patients in the UK had psychological health troubles comprising neurosis, decline in cognitive functions, and other disorders [39]. Corticosteroid therapy is also associated with the progression of psychotic complaints [42]. Correspondingly, after SARS, 5–44% complained of several mental disorders at 1 year comprising nervousness, hopelessness, psychosis, and greater rates of post-trauma stress syndrome [29].
Myalgia (60.0%) and arthralgia (57.2%) were common complaints among the patients included in this study. Correspondingly, post-COVID-19 long-lasting pain may distress patients of various age groups, but the elderly patients are the most commonly affected [43]. Similarly, after the acute SARS, some patients may evolve a chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME)—like a disease with worse sleep quality, lethargy, myalgia, and hopelessness, with some incapable of coming back to their work [25].
Finally, the results of this study are challenged by some limitations. First, the designated sample of post-COVID-19 cases is not entirely illustrative of all post-COVID-19 patients. Second, symptoms that initiated after the date of analysis were not verified in this survey. Third, random selection bias may be present and an inability for personal face-to-face interviews in some cases. Finally, our results were made as a single point of follow-up, and further follow-up at 3, 6, or 12 months would aid further understanding of the progression of symptoms post-COVID-19. So, more studies and researches are desired to better appreciate, describe, and identify the persistent post-COVID symptoms in various sceneries and residents.
