A chronological overview of the contributions of different regions of India towards the cases and fatalities in the two waves
The chronological variations in the number of new cases and new deaths in India (Fig. 1A and 1B) and the contributions of different regions of the country towards the total cases and fatalities of the nation are noteworthy (Fig. 1E and 1F). At the beginning of the 1st wave, the SR accounted for nearly 40% of total cases in March 2020 (Fig. 1C). From April, 2020 till June 2020, the WR remained the major contributor of COVID-19 cases, (43%, 46%, and 31% of the total cases in the respective months). Subsequently from June 2020, when the first phase of unlocking (unlock-1) started in the country (Fig. 1A), till the end of October 2020, the SR contributed 41%, 40%, 34%, and 41% of the total COVID-19 cases of the country in the respective months (Fig. 1C). Only in November 2020, the NR became the highest contributor of new cases (31%), however from December 2020 till February 2021 (in the declining phase of 1st wave), SR contributed 31%, 47% and 43% of the total cases in the subsequent months(Fig. 1C). At the beginning of the rising phase of the second wave, from March 2021 till April, 2021, the WR contributed about 63%, and 30% of the nations’ total cases respectively. In May 2021, the SR once again turned out to be the major contributor of new cases in the country (42%) (Fig. 1C).
In terms of fatality, the WR accounted for the highest monthly fatality from March 2020 till October 2020 (contributed nearly 35%, 59%, 62%, 51%, 41%, 37%, 39%, and 31% of total monthly deaths of the nation respectively) (Fig. 1D). The NR contribute over 33% and 31% of total fatality in November and December 2020. The WR was the highest monthly contributor of COVID-19 related fatality from January 2021 till April, 2021(30%, 40%, 39%, and 33% of total fatality). However, in May 2021, the SR accounted for the maximum proportion of fatality of the country (28%) (Fig. 1D). Thus, it can be inferred from these results that both the Western and Southern Indian states have been the major hotspots of the COVID-19 pandemic in the Indian subcontinent (Fig. 1E, F)
The first wave of COVID-19 in India – A detailed analysis
Apart from Kerala, most of the Indian states reported their first infection in March or April 2020. The Government of India has implemented a nationwide complete lockdown protocol from 25th March 2020 to combat the spread, like many other nations. A continuous lockdown was applied, in four phases, until 31st May 2020. The unlock process, implemented in six phases, commenced from 1st June, 2020 to 30th November, 2020.17 The daily-cases though began to surge steadily, especially from the end of May 2020 (just before the beginning of the 1st phase of unlock) to September 2020 in the majority of the states (Table-1). The adverse effects of unlocking can be understood from the following statistics – from the week, before the last week of lockdown (18th May 2020 to 24th May 2020) to the week, after one continuous week of unlock (8th June 2020 to 14th June 2020), the change in weekly-average numbers of new confirmed cases, active cases, and deaths respectively showed increases from 6369 to 11170 (1.75-fold), from 3153 to 4048 (1.28-fold), and from 144 to 340 (2.35-fold) (analysis not shown).
India reported the maximum number of daily new cases on 16th September 2020 (around 98,000) and maximum active cases on 17th September 2020 (1018454), which was marked as the peak of the wave. Subsequently, both the figures of daily and active cases started to drop steadily in the following weeks, till the end of January 2021, when the number of daily cases reduced to around 10,000 cases/day; marking the trough of the wave.
Among the 10758629 cases reported during the first wave, the highest number of cases was reported from the SR (3933360) which contributed to 36.5% of the total cases. The top contributor state from the SR was Karnataka (about 8.7%), followed by others (Table-1). Lakshadweep islands, which happened to be the last area of SI to report its first infection have contributed minimum to the nation’s total cases (0.0008%). The WR comes next, which contributed 21.6% of the nation’s total cases, where the top contributor state was Maharashtra (reported 2026399 cases, ~ 18.8%). States of the NR, coming next, accounted for about 16.4% of total cases were the highest contributor was the national capital, Delhi (5.9%). The ER shared 11.8% of the nation’s total cases, where West Bengal contributed mostly (~ 5.3%). The CR of India produced 10.7% of the total cases, where Uttar Pradesh (5.5%) was a major contributor. The NER was the lowest contributor of cases and deaths and accounted for only 3% of the total cases of the first wave where Assam shared for the majority of cases (2%), whereas the other 7 states altogether accounted only for 1% of the cases (Table-1). The dates, representing the peaks of active COVID-19 cases, varied for the states and UTs (Table-1).
The CCR (number of cases/1 lakh of the population) was found to be highest in Ladakh (3352 cases/1 lakh) followed by Delhi (3175) and Chandigarh (1773) from the NR. The other states and union territories which reported a case/1 lakh ratio of more than 1000 are Uttar Pradesh (2668) and Chattisgarh (1053) from the CR, Goa (3468) and Maharashtra (1661) from the WR, and Andhra Pradesh (1707), Karnataka (1423), Kerala (2655), Telangana (1103), and Puducherry (2605) from the SR (Table-1).
In addition to contributing the second-highest number of COVID-19 cases, states of the WR also contributed the maximum number of deaths (accounted for 36.4% of the total deaths of the country) during the first wave out of a total of 154428 deaths nationwide. The state of Maharashtra accounted for the most number of deaths in the region (33%), followed by Gujarat (2.8%) and Goa (0.5%). The trend remained similar for the SR, which in line with its highest contribution to the number of cases, also accounted for 24.4% of the total deaths of the nation, where Karnataka (8%) and Tamil Nadu (8%) were the two major contributors (Table-1). Contribution from the Northern states were about 17.7% to the total number of fatalities of where Delhi was the major contributor (7%), followed by other states (Table-1). The CR, in this regard, accounted for 10.5% of the total deaths, where Uttar Pradesh (5.6%) reported the maximum number of deaths (Table-1). Among the 9.5% of the total deaths, contributed by the ER, West Bengal (6.6%) was the major contributor (Table-1). The NER states reported the least mortality and contributed only about 1.51% of the total deaths of the nation (Table-1). The highest CDR was however reported by the national capital, Delhi (54 per 100000 population), followed by Goa (50), Ladakh (45), and Maharashtra (42) (Table-1).
The CFR was found to be highest in the state of Punjab (3.24) in the NR, followed by Maharashtra (2.5) in the WR with Sikkim (2.18) stands next from the NER. The state of West Bengal (1.785) accounted for the highest CFR from the ER, followed by Uttarakhand (1.71), Delhi (1.71) and Himachal Pradesh (1.69) from the NR. Among the states of Southern India, Puducherry (1.66) recorded the highest CFR (Table-1).
Regarding the testing of cases, until the end of January 2021, more than 22.84 crores (1 crore = 10 million) COVID-19 tests were performed all over India, of which the national capital, Delhi (4.81%) recorded the highest percentage from the NR, Uttar Pradesh (12.26%)tops the list from the CR, Maharashtra (6.57%) from the WR, Bihar (9.19%)from the ER, Andhra Pradesh (7.88%) from the SR, and Assam (2.83%) from the NER. The WHO has recommended an optimum of 30, test per case ratio (T: C), as standard; however apart from the states, like Jammu and Kashmir (36.5), Uttar Pradesh (46.6), Gujarat (42.1), Bihar (80.5), Jharkhand (44), Mizoram (48), and Andaman and Nicobar islands (44), all other states and union territories had a T: C ratio less than the WHO recommended mark of 30 tests/case18. (Table-1).
The second wave of COVID-19 in India – A detailed analysis
The period between the end of February, 2021 and early March, 2021, marked the rising phase of the catastrophic second wave of the COVID-19 pandemic in India. During this period, the country reported more than 3 lakhs new cases/day in April that soared to over 4 lakhs cases/day and over 4000 daily deaths in the first week of May, 2021, overburdening the healthcare system of the country. On 6th May, India reported its highest number of over 414280 new cases, which marked the peak of the wave until now. Thereafter, the daily cases started to dip gradually, however the fatality rate remained high.
Starting from 1st February till the 29th May, 2021, India reported a total number of 17134975 cases and over 1.7 lakh deaths. Until 29th May, 2021, the SR remained the top contributor of cases (32%) and the third major contributor of fatalities (22%), where the state of Karnataka (9.5%) and Kerala (9.1%) together accounted for more than half of the total cases of theregion, and again Karnataka (9.3%) and Tamil Nadu (6.3%), like in the first wave, were also the major contributors to the nation’s fatalities (Table-2). Until 29th May, the WR contributed over 25% and 29% of the COVID-19 related cases and fatalities respectively, where Maharashtra was major contributor (21% and 25% of the cases and deaths). The NR contributed about 16% and 27% of the total cases and fatalities respectively, where Delhi, was the major contributor (4.6% and7.7% of cases and fatality respectively). The CR accounted for about 13% and 14.5% of cases and deaths respectively, where Uttar Pradesh was major contributor (6.3% and 6.7% of cases and fatalities respectively). The ER contributed around 10.8% and 7.7 % cases and fatalities of the country respectively where West Bengal is the highest contributor (10.8% and 7.7% of total cases and fatalities respectively). The NER reported the least number of cases (1.63%) and fatalities (2%) in the country, where the major contributor was Assam (over 1% and 1.2% of the cases and fatalities respectively) (Table-2).
Until 29th May, 2021, the highest CFR was reported by Andaman and Nicobar Islands (2.59) where 51 deaths were reported out of 1970 cases, followed by Punjab (2.23) from the NR and Nagaland (2.22) from the NER. The highest number of CDR was found for Goa (118 deaths/1 lakh), followed by Uttar Pradesh (51), and Lakshadweep islands (45). Lakshadweep was also found to contribute highest to the CCR (11084 cases/1lakh), followed by Uttar Pradesh (4835) and Chandigarh (3289). It is noteworthy that apart from Andaman and Nicobar Islands (86 tests/case), Himachal Pradesh (49), and Ladakh (29), the other states and union territories were lagging behind the recommended WHO level18.
One of the major contrast between the first and second wave is the evolution of new variants of the novel SARS-CoV-2 virus during the second wave which triggered a sudden surge in cases in most regions of the country. The three imported viral variants of concern that have been identified in India are the UK (B.1.1.7) variant, the South African (B.1.351) variant and the Brazilian (P1) variant, among which the B.1.1.7 variant was predominantly present in Delhi and Punjab in April, 2021. Among the two novel variants of India, the highly contagious B.1.617 variant from Maharashtra has started evolving rapidly and overtook the B.1.618 variant in West Bengal, and eventually became the major variant in most of the states. The WHO has already designated the B.1.617 variant as ‘variant of concern’ in May, 2021. This variant has spread in all states across the nation and is identified as one of the major causes of the calamity associated with the second wave of COVID-19 in India (especially in Delhi, Andhra Pradesh, Gujarat, Maharashtra and Odisha), as per the study conducted by the Indian SARS-CoV-2 Genomics Consortium (INSACOG), which was launched by the Ministry of Health and Family Welfare, Govt. of India, on 30th December, 2020.19,20
Roles of some major mass-scale public gatherings in the second wave
Mass scale public gatherings like Kumbh Mela 2021 (9 million participants), state elections (covering 243 million residents) have contributed in faster and elevated spreading of the second wave.21,22 A 117-foldincrease in the number of weekly-average new cases and a 266-fold increase in the weekly-average new deaths were found for the state of Uttarakhand when we compared the data between before and after the festival. Uttar Pradesh, like Uttarakhand also showed a sharp jump in the weekly-average new cases and deaths – respectively a 240-fold and 201-fold increase in the numbers of weekly-average new cases and deaths (Table S1 and Fig. S1). These numbers are much higher than the fold-increase found for the cases (20.9-fold) and deaths (35.4-fold) for the entire nation (except these two states) between the mentioned weeks. Five states Assam, Kerala, Puducherry (UT), Tamil Nadu, and West Bengal that witnessed their ‘legislative assembly elections’ (LAE) from late March to end of April 2021 also reported a substantial increase in the average daily cases after the elections compared to some of the states with no LAE or major public gatherings (Fig-S2, Table S2); mainly attributed to the election-related rallies and mass-scale public meetings organized by the local political parties23. However, it is noteworthy that dissecting out the exact contributions of such gatherings from the general increase in the numbers of cases and deaths due to aggravation of the pandemic itself is out of scope.