The current study focuses on the epidemiology and clinical characteristics of 107 COVID-19 cases referred to Firoozgar hospital. Human coronavirus is an important cause of respiratory tract infection. SARSCoV and MERSCoV lead to severe respiratory syndrome in humans, and HCoVOC43, HCoV229E, HCoVNL63, and HCoVHKU1 as other human coronaviruses cause mild upper respiratory disorder.
There was no significant difference between the number of male and female subjects. In many studies evaluating COVID-19 cases, the numbers of men were more than women (1, 13, 14). The decreased vulnerability of women to viral infections may be associated with the protection from X chromosome and sex hormones that are crucial in innate and adaptive immunity (15). Approximately, 30% of cases affected by coronavirus were found with hypertension, diabetes and ischemic heart disease, which is also true for MERS-CoV.19 (13). Our findings indicated that younger cases had remarkably more underlying comorbid systemic disease compared to older cases, which can be associated with underlying diseases that weaken the immune system and increase the risk of infection with coronavirus (16).
GI symptoms are more prevalent among the extrapulmonary manifestations. Nausea, vomiting, abdominal pain, diarrhea, Hepatocellular liver function test abnormalities, cholestasis, and Amylase lipase incensement have been reported in nearly 45% of cases. Some cases of COVID-19 have been observed with GI symptoms as the only manifestation of the disease with no respiratory dysfunctions (9). GI wall permeability is enhanced to foreign pathogens while infected with the virus, GI symptoms, like diarrhea, are observed because of mal-absorption of infected enterocytes (4). Cohort studies have also consistently announced GI symptoms in Covid-19 cases. Another study on 1,099 patients from 552 hospitals in China reported nausea or vomiting in 55 (5.0%) and diarrhea in 42 (3.8%) patients (17). Many cohort studies have revealed diarrhea (2.0–10.1%) and nausea and/or vomiting (1.0–10.1%) in these patients (1, 18, 19). Consistent with the current study, in a cohort study of 140 Covid-19 cases in Wuhan, up to 39.6% of them had GI symptoms, such as nausea (24, 17.3%), diarrhea (18, 12.9%), and vomiting (7, 5.0%) (20). The receptor-binding domain on SARS-CoV-2 is capable of binding to human ACE2 with strong affinity, which is believed to help spread the virus among human population effectively (21, 22). Significant expression of ACE2 in alveolar cells type II (AT2) in the lungs has been reported, and the receptor can be also extensively expressed in the GI tract, chiefly in the small and large intestines (23). Staining of the virus nucleocapsid protein was observed in cytoplasm of gastric, duodenal, and rectal epithelium (24). Thus, it is possible to consider receptor-mediated entry into the host cells can be revealing a basis for its probable transmission way via the fecal contents.
Dermatological symptoms have been recorded in nearly 20% of 107 COVID-19 cases. Erythema has been the most common manifestation, particularly in the patients ≤ 60 years. It has been reported that patients with confirmed SARS-CoV-2 infection might develop cutaneous involvement. In another study on 88 COVID-19 patients, it was observed that erythematous rash, widespread urticaria, and chickenpox-like vesicles are the skin symptoms of the COVID-19. Trunk skin lesions as the main area affected were not somewhat itchy (5).
CoVs are capable of going into the CNS via the bloodstream or neuronal retrograde route causing meningitis and encephalitis along with morbidity and risk of mortality. It is hard to diagnose viral encephalitis due to subtle or lack of symptoms, however, symptoms in severe viral encephalitis are changed mental status and body temperament, unusual behavior or speech, abnormality in motor movement and focal neurological dysfunctions, including flaccid paralysis, paresthesia, hemiparesis, or seizures (7). Assessing 214 patients with COVID-19 indicated that 78 patients (36.4%) had neurological manifestations, like headache, dizziness, acute cerebrovascular diseases, and disturbed consciousness (25).
Studies on the neurological attack in COVID-19 pneumonia revealed that SARSCoV-2 was capable of attacking the CNS and finding the way throughout the systemic circulation or through the cribriform plate of the ethmoid bone. It could then damage the neuronal tissues via interaction with ACE2 receptors. COVID-19 cerebral participation through the cribriform plate can cause more complications, like hyposmia or anosmia (26, 27). Some investigations have reported the likely cerebrovascular endothelial rupture leading to bleeding and irrepressible consequences (27). Due to intracerebral hemorrhage, cerebrovascular accidents have been declared as the rare COVID-19 neurological consequence (28). COVID-19-related acute hemorrhagic necrotizing encephalopathy was found in an individual with changed mental status with nasopharyngeal swab positive for SARS-CoV-2. According to imaging results, symmetric hypo attenuation in the bilateral medial thalami was detected by the head CT, as well as hemorrhagic ring-enhancing lesions in the bilateral thalami, medial temporal lobes, and sub insular areas detected by brain MRI (29). Nevertheless, more investigations should be done for the causation link.
Cardiac and ophthalmological symptoms have been reported in less than 10% of COVID-19 cases in our study. Of 107 studied patients, only 4 cases showed myocardial infarction. ACE1 is the target receptor for SARS-CoV-2 expressing remarkably in the heart. This transmembrane aminopeptidase is linked with developing hypertension, and heart function is essential in the cardiovascular system. Therefore, it is possible to consider cardiovascular injury or myocarditis a COVID-19 manifestation (30). Zheng et al. studied 5 COVID-19 cases with myocardial injury through the course of the disease. Myocardial injury is typically manifested as an elevated level of biochemical markers, such as cardiac troponin I (cTnI), creatine kinase (CK), α-hydroxybutyrate dehydrogenase (HBDB), and lactate dehydrogenase (LDH) (31). The impact of COVID-19 on acute myocardial infarction (MI), such as STEMI and NSTEMI was reported in the new protocols of acute MI (32).
According to the American Academy of Ophthalmology report, conjunctival infection and chemosis are some extrapulmonary symptoms of the infection with SARS-CoV-2 (33). Transmitting by infected ocular tissue or fluid should be more studied and is debated (11, 12). Nasolacrimal system may pave the way for the viruses to travel from the upper respiratory tract to the eyes. Consequently, it is possible to consider ocular tissue and fluid as likely source of SARS-CoV-2. However, in the present study, tear or secretion PCR test for detecting coronavirus was not positive.