Our findings are based on extensive surveillance and contact-tracing data collected from 36 Indian states/UTs. The present investigation was carried out in different states of India and comparative analysis was conducted cutting across various age groups and co-morbidities with comparisons drawn from a previous study which conducted a similar analysis but only in two states viz., Andhra Pradesh and Tamil Nadu 1.
SARS-CoV-2 had been reported from 58 countries and territories around the world as of February 28, 2020, and one international conveyance, the Diamond Princess Cruise Ship 31. As of December 29, 2020, there had been 4 million new SARS-CoV-2 cases and 72,000 new deaths were reported. This brings the cumulative numbers to over 79 million reported cases and over 1.7 million deaths globally since the start of the pandemic32. This study shows that in India, a total number of 11.06 Million SARS-CoV-2 cases, total of 0.16 Million death cases and 10.75 Million recovered cases have been reported. Out of the total cases, 2.13 Million cases were mostly reported from Maharashtra, with 51,993 death cases. Similarly, the vast majority of cases (78,824 out of 83,704; 0.9416 - 95 percent CI 0.94 to 0.9433) and deaths (2,790 out of 2,859; 0.9758 95 percent CI 0.9696 to 0.9809) have been reported from mainland China32. The first U.S. cases of non-travel-related SARS-CoV-2 were confirmed on February 26 and 28, 2020, which clearly suggested the community transmission in U.S. by late February33. The aforesaid data is very important that elucidates the severity of the first pandemic wave of Covid-19 in states majorly affected. Hence, in the current study to get a clear picture, we analyzed all the 36 Indian states/UTs of the country for a comprehensive analysis of various parameters vis-à-vis SARS-CoV-2 infection.
Further, this study compared the CFR among the states that reported a large number of SARS-CoV-2 cases at 12 months of the pandemic, namely Jan 2020 to December 2020. As per our current analysis, it is reported that Maharashtra (2.441%), Punjab (3.215 %), and Sikkim (2.201 %) had the highest CFR than other states of India. In a previous study, a similar analysis has been conducted for the southern states viz., Tamil Nadu and Andhra Pradesh. The findings showed that CFR in all ages was 2.06 (1.98 to 2.14%), and CFR in various ages was also examined1. However, the global picture for CFR as far as the first wave of Covid-19 was also studied in a specified period (12th -23rd of March, 2020) of the pandemic which showed higher CFR rates in Italy (6.22%), China (3.91%), Iran (3.62%), USA (3.07%) and Spain (2.12%)34. The case-fatality ratio was calculated in Turkey as well as European countries including the findings in Turkey, Italy, Spain, the UK, Germany, France, Switzerland, Belgium, Netherlands, Austria, Portugal, and Norway were 1.85, 3.95, 4.01, 4.40, 0.41, 1.979, 1.019, 3.393, 3.496, 0.660, 2.249 and 0.531 percent, respectively35 .
To begin, assume that the number of deaths reported is equal to or very close to the actual value in the investigation, which may not be the case in many countries. The CFR was calculated for each period, namely period I (January to March 2020), period II (April to June 2020), period III (July to September 2020), and period IV (October to December 2020). Our finding also proved that the CFR was significantly increased due to a lack of facilities in the initial days and thereafter the CFR trend decreased as facilities were getting improved. Ideally, the CFR should be low at first due to the incubation time and delay in developing complications from the infection, which was gradually increased until it reaches a plateau that will eventually become the ultimate CFR for the diseases. Although the number of cases started increasing in period II and III, it is also to be noted that the number of samples tested were also proportionally higher during that period. From the first case reported in India in January 2020 to the start of the first wave, the number of labs equipped to test the samples were very less in number, but eventually, the testing centers increased in India36,37. The first wave in India occurred relatively for a extended period of time, and the reasons may be due to multiple lockdowns and restrictions. The nationwide lockdowns during the second quarter of the year 2020 and further lockdowns down the year have slowed down the spread of SARS-CoV-2, which has contributed to the extended period of the first wave.
In the present investigation, SARS-CoV-2 patients suffered from several co-morbidities which were further classified into two: Acute and Chronic. The incidence percentages of acute and chronic were 12.87% and 87.13%, respectively. In India, it is important to know the mortality rates related to different age groups and underlying co-morbidities. Further, the first wave saw a high risk for co-morbid patients affected with SARS-CoV-2, which is due to the dearth of knowledge attitude, and practices (KAP) for a relatively new disease with less proven treatment protocols. Hence, it is important to analyze the data on COVID-19 in co-morbid patients, so that it could be a model for implementation in high-risk populations 38. Also, the lessons learned from the first wave of COVID-19 is altogether different compared to the second wave, with the first wave having the unmutated strain of SARS-CoV-2 that showed fewer positive cases but more CFR. The Omicron BA.1 strain thus exacerbated the condition in patients with co-morbidities due to a lack of KAP and clinical infrastructure.
Furthermore, elderly patients with underlying co-morbidities such as diabetes, hypertension, cerebrovascular disease, and cardiovascular disease, are more likely to have negative outcomes 39. People of any age who have underlying medical conditions such as hypertension or diabetes have a worse prognosis40. Diabetic patients have higher morbidity and mortality rates, as well as more hospitalizations and intensive care unit (ICU) admissions 40. Diabetic patients are more prone to the deleterious and severe effects of the Covid-19 which is due to the fact that the inflammatory processes are elevated because of constant glucose recognition by C-type lectin receptors and advance glycation end products (AGEs) that subsequently culminates into an uncontrollable proinflammatory response leading to ‘cytokine storms’ 41,42. Despite having a huge number of COVID-19 patients, it is surprising that there are currently just a few sizable published studies available regarding the prevalence of comorbidities in patients with COVID-19 from India. The presence of comorbidities was reported in 14% (95% CI, 11.1-17.2) of the 522 confirmed COVID-19 patients from a large medical college and hospital in Jaipur, India. Of these, hypertension (42.5%), diabetes (39.7%), past history of tuberculosis (20.5%), COPD/asthma (16.4%), CAD and CKD (13.7%), and hypertension were the most common43. Similarly, patients affected with hypertension are medicated with anti-hypertensive drugs that increase the expression of ACE2 receptors and release of proprotein convertase, which eventually aids the entry and multiplication of SARS-CoV-2 through these receptors, leading to a high risk of infections and other clinical complications in them. Because in Italy alone the mortality associated with hypertension due to covid-19 is 73.8 percent which is much alarming44. People with chronic obstructive pulmonary disease (COPD) or any other respiratory illness are more likely to develop severe SARS-CoV-2 illness45. The severity of SARS-CoV-2 infection is more likely to be increased by four times in patients with COPD than in patients without COPD 45. The elderly, particularly those in long-term care facilities and people of any age with serious underlying medical conditions are at a higher risk of contracting and developing severe SARS-CoV-2, according to current research and clinical expertise46. The poorly orchestrated immune response coupled with severely elevated ACE2 receptor and furin expression exacerbates the lung condition leading to COPD, hypoxemia, and mortality44. The population having chronic health conditions like cardiovascular, diabetes, or lung disease is not only at a higher risk of developing severe illness but also has higher chances of mortality if they become ill 47. People with uncontrolled medical conditions such as hypertension, diabetes, lung, liver, and kidney disease, pathogenic co-infections, smokers, transplant recipients cancer patients on chemotherapy, and patients on long-term steroid therapy are more likely to contract and develop severe SARS-CoV-2 infection 46,48. Chronic obstructive pulmonary disease (COPD), among other co-morbidities, has been linked to poor disease progression. A four-fold increase in mortality in patients with pre-existing COPD who were diagnosed with SARS-CoV-2 has been found in a meta-analysis of multiple Chinese studies45. Similarly, obesity with a higher BMI predisposes to all the risks including hypertension, diabetes, and hypothyroidism all of which are excellent playground for risk and associated severity of Covid-19 related complications and mortality 49.
The influence of age on number of positive cases and disease severity has also been analysed in this study. The age criteria were classified into 4 different class intervals namely: <20 years, >21-50 years, >51-80 years and >80 years. Out of these, the incidence percentage was higher in >21-50 years class of interval followed by others. It is essential to know the critical age groups which are most affected during the pandemic situation, so that effective preventive measures can be undertaken for the high-risk group. It is shown that the CFR of SARS-CoV-2 increases with ages 46, 50 across different countries. The Italian population (23%) was either 65 years of age or older51. This would explain the higher mortality rates in Italy compared to other countries. A similar study has been reported by Russell and his coworkers, for the detection of infection and CFR for SARS-CoV-2 in February 2020 using age-adjusted data (0-9 years, 10-19 years, 20-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years, 70-79 years, 80-89 years) from the outbreak on the Diamond Princess cruise ship. The highest CFR of 14.8% was detected in the age group between 80-89 years, and the contrasting findings in the children with mild symptoms and less positivity show the age-specific affection during the first wave of the pandemic52. Similarly, the CFR rate of SARS-CoV-2 is reported to be higher in older adults than younger individuals i.e. 42% for those <65 vs 65% > 65 years; and the association of chronic conditions and risk of dying across different age groups follows the same trend53. This study also reported that the global mortality cases stood at 2.68 million. The mortality cases were higher in United State (538 thousand) followed by Brazil (282 thousand) and India (157 thousand). This depicts that India has the third highest mortality rate globally during the reported period. In India, Maharashtra recorded high mortality followed by Tamil Nadu and others. Similarly, earlier studies reported that in Tamil Nadu, the crude death rate was 2.44 per lakh population; while the elderly (> 75 years) showed a mortality of 22.72 percent. Also, the study pin points that around 85% of affected were reported to have one or more comorbidities including a higher proportion of diabetes followed by hypertension and others54. Whereas in one study conducted in Maharashtra, it was reported that the age group from 31-60 years were majorly affected due to Covid-19 during the first wave with the mean age being 45.8 years, while hypertension was the most common comorbidity followed by diabetes55. And the overall percentage of mortality due to SARS-CoV-2 cases was significantly higher in the Western zone as compared to other zones. Wuhan had a higher mortality rate of 4.9 percent, while its’ province Hubei had a lower mortality rate of 3.1%. In China, a significant proportion of deaths (26%) occurred in people over the age of 60. However, at this stage in the epidemic's evolution, temptations to make policy decisions based on mortality data should be avoided 56. The age-specific SARS-CoV-2 death rate in Korea was higher among patients over 70 years of age with underlying diseases in their circulatory system such as arrhythmia, cerebral infarction, hypertension, and myocardial infarction57. A recent study has proved the highest mortality rate per million inhabitants of SARS-CoV-2 cases in Belgium between April 11, 2020, and August 26, 202058.
Similarly, two groups of countries emerged, one with a higher mortality rate (Spain, Italy, and the United Kingdom) and the other with a lower mortality rate (USA, Germany, China). This analysis showed that the mortality in Maharashtra was higher because of the poor adherence to the safety norms and due to the most visited, crowded place in India. Furthermore, countries like Iran began to report or test cases only after higher fatalities59. It is also to be noted that higher CFR values were reported at the initial stages of the pandemic.
There lies a relational trend between higher CFR rates and advancement of the pandemic in the first wave of 2020. This could be largely due to the temporal adaptation of the virus in the population. This explains why period II showed the peak CFR, followed by a decreasing trend in the CFR.
Similarly, the first wave in India has non-immunization control, where vaccination was not practiced widely in the population. The pandemic dynamics of the first wave actually represents the Omicron BA.1 that created the pathogenesis without any herd immunity. This data can further be compared with the second wave CFR and disease pattern caused by a novel strain (delta and delta plus variant) in the future. The comparison of these data on CFR vis-à-vis the immunization that was started at various stages of second wave could provide a meaningful conclusion on the pandemic dynamics and herd immunity.