Clinico-epidemiological profile of COVID-19 cases: Our experiences

A novel beta coronavirus, which was named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2

The World Health Organization (WHO) declared this outbreak as a global public health emergency of international concern on January 30, 2020. Since the outbreak, of COVID-19, the disease has spread worldwide; and the number of infected cases has grown exponentially. [7,8].

Aims & objectives
To study the clinico-epidemiological profile of hospitalised COVID-19 cases in an urban area. (a) To determine whether there exists an association between Diabetes Mellitus and risk of developing severe COVID-19, (b) To determine whether there exists an association between Diabetes Mellitus and risk of mortality due to COVID-19, (c) To determine whether there exists an association between other comorbidities and risk of developing severe COVID-19, (d) To determine whether there exists an association between other comorbidities and risk of mortality due to COVID-19.

Material and methods
The workers carried out a cross sectional descriptive study. Period of the study was 01 April 2020 to 31 December 2020. The study was carried out across several urban areas in India. Detailed epidemiological, clinical, laboratory and radiological data pertaining to date of onset of symptoms, date of admission, movement history during the known incubation period, history of having had contact with a known COVID-19 positive case, whether individual was under quarantine or not when tested for COVID-19, details of various investigations carried out during the course of hospitalisation and other relevant data was obtained from each case. The cases were sorted as mild, moderate, and severe COVID-19 based on the SpO2 and oxygen requirement [9]. Above data in respect of 332 cases of COVID-19 was obtained.
All the above data was obtained as part of routine surveillance of the COVID-19 pandemic situation. The study team thoroughly reviewed all the cases which occurred during the period of study. A detailed clinical and epidemiological history was elicited.
Only cases confirmed to be COVID-19 by reverse transcription polymerase chain reaction (RT-PCR) and admitted to the hospital in consonance with the local policy were considered. The entire data obtained pertaining to all the cases was unlinked and anonymous. Ethical clearance from the institutional ethical committee was obtained prior to the conduct of the study.
The data was entered into an MS excel file. Data was subject to appropriate statistical tests. Quantitative variables were described using mean, median, minimum, maximum, and standard deviation and SD and qualitative variables were described using proportion. On bivariate analysis association between the variables were assessed using chi square test and the adjusted and unadjusted OR were assessed along with 95% confidence interval. All variables which were significant were included in the multivariate logistic regression to predict the association of the factors with severity as well as mortality associated with COVID-19. All the tests were two tailed; and the significance was set at 5%. P value less than 0.05 was considered statistically significant. Statistical package used was SPSS 23.0.
Sex and age wise distribution of the cases is tabulated in Table 1.

Laboratory and other investigations profile
X-ray chest in respect of all the cases except seven (2.10%) was unremarkable. In these seven cases, there was some evidence of pneumonia, which was confirmed by computerized tomography (CT) scan.
CT scan was not carried out in the remaining cases due to resource constraints. The pneumonia in all the cases resolved after five to seven days.
Out of 332 cases who were RT-PCR positive for COVID-19 at the time of admission, repeat RT-PCR  Table 2.
Differential leucocyte count was within normal limits in all the cases. Other inflammatory markers like procalcitonin and Interleukin 6 were not carried out due to resource constraints.

COVID-19 and other comorbidities
Commonest comorbidity observed among the cases was diabetes which was seen in sixty seven (20.18%) of cases. Ischaemic heart disease, bronchial asthma and chronic obstructive pulmonary disease were observed in twelve (3.61%), nine (2.71%) and five (1.50%) cases respectively. When the data was analysed by logistic regression significant association was seen with diabetes mellitus, Age >70 years and Bronchial Asthma with severity of COVID-19 infection. The findings are summarised in Tables 3, 4 and 5 below.   Kumar et al observed fever, fatigue, headache, cough, difficulty in breathing, and sore throat to be the commonest symptoms of COVID-19 [11]. Alfonso J et al reported fever (88.7%, 95%CI 84.5-92.9%), cough (57.6%, 95%CI 40.8-74.4%) and dyspnea (45.6%, 95%CI 10.9-80.4%) as the most prevalent clinical manifestations in their systematic review and meta analysis, while Umakantham et al reported non specific symptoms such as fever, cough and myalgia as the commonest symptoms [2,12]. These findings are similar to that of our study wherein the commonest symptoms were fever (70.78%) and breathing difficulty (28.01%) .00001) were associated with a higher risk of death due to COVID-19 [16]. Several workers have reported presence of diabetes to be significantly associated with severe COVID-19 as well as mortality due to COVID-19 [17][18][19].
These findings are different from that of our study wherein older age, and diabetes were significantly associated with severity of COVID-19.
Rodriguez-Moralesa et al also reported that at least one fifth of cases require supportive care in medical intensive care units; and a case fatality rate ranging from 11% to 15% [2]. These findings are different from our study wherein we observed that 36.14% required supportive care either in the form of oxygen or ventilator; and a case fatality rate of 2.10%. Jain et al also reported a lower mortality rate due to COVID-19 in India as compared to western countries, though the exact percentage mortality has not been specified by these workers [13].

limitations
One of the major limitations of this study is that it is a cross sectional descriptive study. Our study has also shown an association between age more than seventy years and severe COVID-19, asthma and severe COVID-19; and diabetes and severe COVID-19. However, since the study is a cross sectional descriptive study, the workers have been able to calculate the odds ratio both unadjusted and adjusted. Another limitation of this study is that Berkesonian bias (hospital bias) may have set in as only hospitalised cases of COVID-19 were included in the study.

Conclusion
Asymptomatic or flu-like symptoms such as fever, cough, myalgia, rhinorrhea, and sore throat, to acute respiratory distress syndrome (ARDS) or multiple organs failure constitute the wide range of clinical manifestations of COVID-19. Majority of the cases in our study shared similar clinical features and laboratory parameters. In majority of cases, COVID-19 presents with a rapidly progressive course of fever, cough and dyspnea. Eliciting a history of recent travel to areas with ongoing outbreaks of SARS nCoV2 or contact with a confirmed case of COVID-19, should prompt clinicians to initiate isolation precautions and carry out laboratory confirmation. The workers recommend that more research be carried out to identify various agent, host and environmental factors which may play a significant role in the pathogenesis of severe and fatal infections.

Conflicts of interest
Authors declare no conflicts of interest.