Since December, 2019, coronavirus disease 2019 (Covid 19), originated from Wuhan, China, has rapidly spread across the globe, as evident by declaration of this latest threat by World Health Organization as pandemic in March, 2020. With exponential surge in morbidity and mortality, the world is witnessing the rampage by Covid 19. As on 19th April, 2020, causing more than 2 million cases and 160,000 deaths, the virus has put the limitation of health system in most the countries on display. With a reproductive number between 2 and 3, Covid 19 is expected to keep the world on its toes for at least near future. (1) The case fatality rate appears to be low but because of high infectivity, the overall number of patients requiring  intensive care is large enough to saturate the capacity of the health system in majority of the  countries. With devastating impact on public health and economy as well, the virus is probably one of the greatest threat faced by human being in all times. 

India, in spite of being in neighbourhood of the epicentre, experienced the wave later than Europe, the 100th case from the country being reported recently on 15th March, 2020. Learning from the responses of other countries, the Government, in addition to suspending international flights, closing borders and adopting extensive use of quarantine/ isolation, soon imposed a nation-wide lockdown from 25th March, 2020, along with vigorous emphasis on raising mass awareness on social distancing and personal hygiene. (2) With the restriction further extended till 3rd May, 2020, the mid-term impact of lockdown on the progress of the epidemic could be assessed from available data (from the website of Ministry of Health and Family Welfare). 

For analysis, date wise new cases were arranged in blocks of seven days, starting after 15th March, 2020, the day India recorded 100th case. Any variation between days (weekend, for example) was supposed to be nullified in this strategy. Block wise growth rate, in terms of number of new cases and deaths reported, was displayed in Figure 1. As evident, there was initial hike in growth rate for new cases, followed by gradual decline over the blocks. Growth rate for new reported deaths was also seen decreasing. As the duration of lockdown increases, its effect on the epidemic gets clearer. 

The decline in number of cases or deaths could be ascribed to this proactive lockdown, along with other prohibitions mentioned earlier. What happens once the lockdown is over would remain a matter of speculation. It is envisaged to withdraw curbs gradually, starting with the districts having no evidence of infection. Fortunately, such districts constitute more than 45% of the country. (3) 

However, there were several other factors which might determine the trend. One is limited number of tests, as compared to other countries. With less than 300 tests per million population (4), India lags much behind the developed countries. However, as the proportion is gradually increasing, it could have influenced the trend in both ways. Another factor is religious/ social gatherings being reported, even after putting restriction on the same. A third factor could be cooperation from the citizen and the role of the Government in ensuring the same. Kerala, one of the states from India, is already on its way for achieving control. (2) 

With two weeks yet to go before lockdown ends, India is demonstrating the strategy to contain the pandemic. Post-restriction period would really be an acid test, particularly for the community because of its larger role. Doubt about post-lockdown containment of epidemic has been expressed earlier. (5) The objective would remain not to overwhelm the existing health structure with thousands of patients in need of intensive care and ultimately, to save lives. 

References

1. Del Rio C, Malani PN. COVID-19-New Insights on a Rapidly Changing Epidemic. JAMA. 2020;323(14):1339-40. 
2. Chetterjee P. Gaps in India’s preparedness for COVID-19 control. Lancet Infect Dis 2020 [Published Online April 17, 2020] https://doi.org/10.1016/ S1473-3099(20)30300-5. 
3. Govt. of India. Updates on COVID 19. 16th April, 2020. (Available from https://pib.gov.in/newsite/pmreleases.aspx?mincode=31, last accessed on 19th April, 2020) 
4. Indian Council of Medical Research. SARS-CoV-2 (COVID-19) Testing: Status Update 19 April 2020 9:00 PM IST. Available from https://icmr.nic.in/sites/default/files/whats_new/ICMR_testing_update_19April_9PM _IST.pdf, last accessed on 19th April, 2020) 
5. Peto J, Alwan NA, Godfrey KM, et al. Universal weekly testing as the UK COVID-19 lockdown exit strategy. Lancet. 2020. [Published Online April 17, 2020] https://doi.org/10.1016/ S0140-6736(20)30936-3.