The COVID-19 pandemic is an emerging worldwide health problem which has infected millions of people globally2. The notion of lockdown was linked with the incubation period of COVID-19, which is a median of 5.1 days and can be up to 14 days [4]. The lockdown policies have been enforced in many countries to reduce the spread of COVID-19 [6]. For a treatment to be successful at keeping an epidemic under control it must first cause the rate of growth per day to become negative and the growth rate to the growth rate per day to become negative fall to below 1.0, which would indicate an exponential decay in the number of cases.
In this study, we investigated the impact of 15 days before, 15 days during and 15 days after lockdown on the epidemiological trends in the prevalence and mortality because of the outbreak of novel coronavirus SARS-COV-2. We found that 15 days after the international lockdown there was no significant decline in the mean prevalence and mean mortality rate due to COVID-19 compared to 15 days before and 15 days during the lockdown in 27 countries. However, daily cases of COVID-19 and growth rates showed declining trends by the end of the 15 days after the lockdown period, leading to a critically important negative growth rate per day by the end of the lockdown period for both new daily cases and deaths. This negative growth rate per day in these two categories (meaning the increase in cases was decelerating) indicated that from a public health perspective, the lockdown had a positive effect on the pandemic. However, the growth rate never fell to below 1.0 immediately following the lockdown, so the lockdown was not sufficient to stop the pandemic, which is borne out by obvious international persistence of this infection and a growing worldwide death rate.2 This has caused countries to impose new lockdowns and encourage residents to isolate themselves in their houses.
Nussbaumer-Streit et al. 2020 [12] in a recent review on lockdown demonstrated that this type of measure has had an effective impact at reducing the incidence and mortality of COVID-19 during the current pandemic. This article recommended that along with other public health procedures, lockdown should be enforced at an early stage to prevent the COVID-19 infection from spreading further. The study has shown evidence that lockdown measures are consistently beneficial, with quarantining of people who were exposed to confirmed or suspected cases preventing 44% to 81% of new cases and 31% to 63% deaths, compared to a lack of any lockdown measure. The authors showed that a lockdown may prove helpful in controlling the COVID-19 outbreak. Our study showed that the lockdown was beneficial in decreasing the rate of growth per day of infection, but ultimately insufficient to bring the absolute growth rate down to 1.0 or less which is the point where an epidemic is clearly under control. The concept of a lockdown is theoretically attractive because it minimizes the number of people exposed to contagious patients and therefore fewer people will be susceptible to getting infected [13].
A lockdown may play an important role when vaccination or prophylactic treatment is not possible, as has been the case with COVID-19 pandemic. In this report, we analyzed the impact of 15 days before 15 days during and 15 days after a lockdown on the prevalence of COVID-19 cases in 27 countries. We found that daily cases of COVID-19 and growth factor results show a declined trends 15 days after the lockdown period. The present study findings did not support our hypothesis that lockdown will significantly decrease the number of cases.
Manchein and colleagues 2020 [14] analyzed the growth of the cumulative number of COVID-19 cases from various countries until the last week of March 2020. Their study findings show that soft lockdown approaches are not suitable to flatten the growth curves. They also found that along with social distancing of individuals, the strategy of identifying and isolating infected individuals at daily basis and large levels can help to compress the curve.
In addition, Bensimon and Upshur 2018 [15] and Greenberger 2018 [16] reported that the efficacy of a lockdown is uncertain. The present study findings are consistent with those of Manchein and colleagues 2020 [14], Bensimon and Upshur 2007 [15], and Greenberger, 2018 [16], that lockdowns or quarantines may also need additional supportive measures such as proper information, social distancing, and hygienic measures to eradicate an epidemic.
In few countries there was a positive impact of lockdown to minimize the incidence of SARS-COV-2. But, this is also fact that, in many countries especially the developing countries long-term lockdown was not sustainable as it has various social, psychological and economic impact. Future lockdown policies should adhere to optimizing behavior such as social distancing and mask wearing associated with social and cultural factors that can affect in minimizing the COVID-19 pandemic, because lockdown alone will not be effective if people will not adhere to this policy.
Study strengths and limitations
This is the first article in the literature, to our knowledge, that has investigated the impact of a lockdown on epidemiological trends of prevalence and mortality of the COVID-19 pandemic, and our findings are based on the twenty seven countries worldwide. During the COVID-19 pandemic, to date, only mathematical modeling-based reviews have been published to hypothesize the impact of a lockdown on the prevalence of COVID-19 cases. This is the first study, which analyzed the impact of 15 days before, 15 days during and 15 days after lockdown on the prevalence trends of COVID-19. Another strength is that the study data were gathered using reliable sources including “World Health Organization, and concerned countries”. We also analyzed the growth factor and the growth rate per day, which are vital metrics to determine the epidemiological trends of a pandemic. A limitation is that we were unable to investigate confounding factors including how much people vary in: (1) adherence to lockdown, (2) adoption of protocols of social distancing, (3) practice of health hygienic conditions and (4) experience disease testing systems of their individual countries.