While Halpin et al.  referred to them as “post-discharge” symptoms in a COVID-19 follow-up study, Islam et al. broadly described them as “post-viral fatigue” symptoms . We aimed to infer whether these symptoms, which include, malaise, myalgias, lack of concentration, sleep disturbances, and others, were present following infection with COVID-19 disease. Existing literature has described the post-viral fatigue in moderate to severe cases of coronavirus recovered patients, it was unclear whether mild cases exhibited a similar symptomatology. One of the reasons from the rationale of studying mild cases only, was that Demeco et al.  reported that in the majority, 81% of patients, COVID confers a mild disease. In addition, Garg et al.  suggested in an editorial that a subgroup analysis of only mild COVID-19 patients would provide more insight to the post-viral fatigue syndrome as there is a scarce chance of chronic organ impairment in these cases. Therefore, in this study we aimed to identify residual symptoms in patients who recovered from mild COVID-19 disease due to infection by the SARS-CoV-2 virus.
Though a number of studies are still underway, and no consensus has been reached regarding the cut-off for how long the post-viral symptoms persist, following are some notable reported narratives. A study in Wuhan of 131 patients found that 29% of their patients had persistence of symptoms at a two week follow up . Carfi et al.  reported that, 87.4% recovered patients had persistence of at least one symptom, particularly fatigue and dyspnea at an average of 48 days post-discharge. In a survey led by the center for disease control and prevention (CDC) COVID-19 response team, amongst symptomatic adults with mild disease patients, 35% of the participants had not returned to their usual baseline health at 14–21 days after testing positive, with 47% amongst these being ≥ 50-years old .
Halpin et al.  observed that fatigue was the most commonly occurring symptom during follow-up for both ward (60.3%) and ICU (72%) patients, followed by respiratory symptoms (shortness of breath), while in our study, respiratory sequelae (cough and chest pain) were the least prevalent. It should be taken into consideration that moderate to severe cases of coronavirus result in diffuse lung injury, pulmonary infiltrates along with respiratory distress. Furthermore, the patients in an ICU setting may require mechanical ventilation secondary to acute respiratory distress syndrome (ARDS) and pulmonary fibrosis. It can be inferred that persistence of respiratory symptoms seen in such cases may stem from long-term lung injury associated with more severe forms of the disease and hence, were not observed in our cohort.
A notable result from our study was the occurrence of sleep disturbances in 18.3% of healthy adults without any co-morbid conditions, which formed majority of the sample population (88%), and in 41.4% of patients with existing co-morbidities, which was a statically significant finding. This renders that a strong correlation exists between disordered sleep and the presence of co-morbidities. Altered sleep patterns have previously been reported by Moldofsky et al.  who documented the presence of non-restorative, unrefreshing sleep for as long as 19.5 months in patients suffering from the chronic post-SARS syndrome (2003). Another study by Xiong et al. reported 17.7% of their survivor cohort had sleep disorders after the onset of the disease . It shows that not only can disturbed sleep occur in all age groups, but for prolonged time periods as well. Altered sleep can be owing to isolation during lockdown, social distancing from family and friends and phobias associated with the pandemic.
There was an evident association of majority of the symptoms, specifically, decreased appetite, chest pain, headache, low mood, sleep disturbances, fatigability, myalgias, and nausea/vomiting with female gender. Similarly, Xiong et al.  related physical decline/fatigue, post-activity polypnea and alopecia as being significantly more common in female survivors. Thus, an association of post-COVID sequelae with gender exists and demands further research.
We acknowledge some shortcomings in our study. Ours was a single-center study with a small sample size and the findings weren’t compared with a control group. Moreover, there always exists some element of recall bias with follow-up studies. The post-COVID syndrome is a fairly new dilemma seen in COVID survivors and we still know relatively less about the long-term effects of the disease as we have only months of experience to draw on. Additionally, in more severe forms of the disease, the occurrence of the cytokine storm has proven to be a predictor of chronic fatigue syndrome (CFS) like symptoms in COVID-19 survivors, whereas, for less severe forms of the disease, there is still a need to study the pathogenesis leading to the occurrence of the post-COVID syndrome which cannot be explained entirely by the cytokine storm. Lastly, it is important to include various ethnicities and socio-demographically diverse groups in study samples to study the association of the post-COVID syndrome with the ethnicity.