JMIR Publications

ABSTRACT

Background:

By the end of the first year of the pandemic, the US had the highest global cumulative COVID-19 case and death count [1]. Additional challenges such as newly emergent lineages of SARS-CoV-2 with increased transmission potential [2] and issues in COVID-19 vaccine distribution and administration have increased the burden on public health systems globally. Implementation of public health and social measures (PHSMs) such as stay-at-home orders, limited gatherings, and closure of non-essential workplaces is a crucial way to prevent and mitigate the spread of COVID-19. Last year we developed the Health Intervention Tracking for COVID-19 (HIT-COVID) global database to catalogue the implementation and relaxation of COVID-19 related public health and social measures (PHSMs) [3]. Many other PHSM surveillance systems also collect data that can be utilized to inform pandemic responses [4-6]. These PHSMs have been shown to be effective, both individually and in combination, against COVID-19 globally. For example, a recent study found that from January to May 2020, limiting gatherings, closing businesses, closing schools and universities, and stay-at-home orders were individually effective at reducing Rt in 41 countries [7]. An earlier study found that in combination, limiting gathering sizes, business closures, educational institution closures, and stay-at-home orders reduced COVID-19 transmission from January to May 2020 in 11 European countries [8]. Implementation of PHSMs is a key marker of how public health systems address the COVID-19 pandemic. Poor COVID-19 outcomes in the US have been attributed to a failure to consistently, quickly, and effectively implement PHSMs [9].

Objective:

We sought to analyze the epidemiological evidence for PHSM impact on COVID-19 transmission in the US compared to that in ten other countries — places that provide sources of learning to the US.

Methods:

We analyzed timing and stringency of PHSM implementation through November 25, 2020 against time series for daily case counts of COVID-19, comparing the US to Canada, China, Ethiopia, Japan, Kazakhstan, New Zealand, Singapore, South Korea, Vietnam, and Zimbabwe. These 10 countries were chosen for comparison to the US based on their varying income levels and geographies, and were selected as comparators to the US COVID-19 response in a previously published high-profile commentary on global PHSM effectiveness [9]. Canada was chosen for its comparatively lower death rate, China for being the first country affected by COVID-19 and having a large population, Japan for its more elderly population, New Zealand for being geographically isolated, Singapore and South Korea for their geographic proximity to China, Vietnam for being a lower-middle-income country, and Ethiopia, Kazakhstan, and Zimbabwe for having less medical infrastructure and manufacturing capacity. For ease of analysis we focused on eight groups of PHSMs (border closures, contact tracing, household confinement, mandated face masks, quarantine and isolation, school closures, limited gatherings, and state of emergency). Stringency of these PHSMs was classified in the Health Intervention Tracking for COVID-19 (HIT-COVID) surveillance database as strongly implemented, partially implemented, or not implemented [3]. PHSM and case count data was derived from the HIT-COVID database, the World Health Organization PHSM global database, and the European Centre for Prevention and Disease Control [5,10]. For each country, the date and stringency of PHSM implementation was plotted against the number of daily national cases. Additionally, we compared the 11 countries’ cumulative incidence rates with 40 variables describing national measures of social, demographic, economic, and health systems characteristics [11-14]. Analysis was performed using the HIT-COVID R package in version 4.0.3 [15].

Results:

Figures 1 and 2 compare COVID-19 epidemic curves with timing and stringency of PHSMs across countries. The results show that implementing a specific package of PHSMs — quarantine and isolation, school closures, household confinement, and limiting social gatherings — earlier and more stringently was associated with limited cases and transmission duration in Ethiopia, and Kazakhstan, New Zealand, South Korea, Vietnam, Zimbabwe, particularly in comparison to the US. Singapore and South Korea implemented similar PHSMs with less stringent household confinement, but both have substantially lowered the epidemic curve compared to the US. China implemented fewer PHSMs for shorter durations with more targeted sub-national implementation. Japan implemented strong quarantine and isolation measures along with early school closures, but otherwise did not maintain the same level of stringency with the package of PHSMs. Canada initially implemented strict PHSMs, but then did not maintain the level of stringency across the country and is now suffering from a resurgent epidemic and relatively higher cumulative incidence rate, though still much lower than the US. In comparison, the US did not implement the package of four PHSMs that were shown to be effective in the six other countries mentioned above. The US implemented few PHSMs fully or early in the pandemic. While the US government implemented several PHSMs early in the pandemic, those PHSMs were only partially implemented, not strongly implemented as in most other countries in this analysis. Border closures, state of emergency declarations, and mandated mask wearing do not show strong associations with epidemic growth across these countries, though some may have been important in individual countries (e.g. border closures in New Zealand), and adherence to mask wearing seems to vary widely. These countries differ significantly in many demographic, economic, social, and health systems characteristics that may explain their varying success in controlling COVID-19. Comparing the countries’ cumulative incidence rates with national measures of social, demographic, economic, and health systems factors, we found only one positive association between national income and cumulative COVID-19 incidence (Figure 3). Poorer countries performed better than wealthier ones, with the poorest three countries having the lowest incidence and the wealthiest two having the highest incidence. Figure 2. Cumulative COVID-19 Incidence Rates and National Income Levels [1,11].

Conclusions:

Efforts to control COVID-19 have ranged from earlier, stricter measures of border closures and nationwide lockdowns to less stringent individual behavior change campaigns and public health recommendations. The exact mixture of approaches, timing, and intensity has varied across regions, countries, and often within countries, depending on their size and governance structure. Public health experts have stated that early and stringent implementation of mitigation strategies is key to pandemic control, with greater reductions in downstream cases and fatalities [9]. One study found that globally, timing of PHSM implementation was significantly associated with reduction in COVID-19 transmission as measured by the R ratio [16]. Our analysis suggests that timing, as well as stringency, is associated with lower caseload and transmission in the examined countries. An advantage of our analysis is that the HIT-COVID dataset includes a measure of implementation stringency for each individual PHSM (strongly, partially, or not implemented). Most other databases classify PHSM stringency according to the strictness of behavior-related PHSMs; thus, it is dependent on the type of PHSM as well as its implementation [17]. The package of PHSMs that we found to be associated with decreased COVID-19 cases and transmission have been shown to be effective in other studies — quarantine and isolation orders, school closures, household confinement, and limits on social gatherings — further providing evidence that these specific measures help reduce the spread of the pandemic [7,8]. Implementing effective COVID-19 PHSMs requires coherent national leadership and coordination as well as necessary resources. The US government’s pandemic management has been highly fragmented. While a more unified response has been called for by US American public health leaders, the US has a strong history of state-level policymaking, creating logistical and cultural challenges to implementing stringent national PHSMs. Additionally, cultural distrust in public health and medicine may have contributed to implementation of PHSMs later than recommended by public health experts. Our findings underscore that early coordinated implementation, consistent enforcement, and/or high societal adherence for an adequate duration were vital to controlling COVID-19 successfully in many countries. Additionally, while the US is a high-income country, low hospital workforce capacity, lack of affordable healthcare, and high prevalence of preexisting conditions may increase the population's vulnerability to COVID-19 [18]. In the US, lack of resources and intervention fatigue combined with political pressure to reopen earlier than public health officials recommended may have contributed to an out-of-control pandemic that has infected over 27 million Americans and left over 480,000 dead [1]. Our finding of a positive association between national income and COVID-19 cumulative incidence raises further questions. Another study found that national income was positively associated with COVID-19 incidence and death rates across 210 countries; however, this article has not been peer-reviewed [19]. Our result may be explained by the timing of PHSM implementation. According to Fig 1, lower-income countries implemented the package of PHSMs early, making them more effective in mitigating COVID-19 transmission. Additionally, higher-income countries may face higher COVID-19 transmission due to increased availability of international air travel. It is also possible that well-funded public health reporting systems and availability of COVID-19 testing in higher-income countries is a contributing factor. Finally, country-specific factors such as government structure, trust in public health and medicine, and centralization of the pandemic response play a role in COVID-19 transmission and may be related to national income. The influence of these factors bears further analysis. Our analysis has several limitations. Our sample size of only 11 countries limits the power of our analysis. We were not able to capture how inadequate policies exacerbate racial/ethnic inequities in COVID-19 outcomes. In the US, the number of cases is 2.8 times higher among Indigenous Americans and Latinxs, and 2.6 times higher among Black Americans, compared to Whites [20]. The age-adjusted mortality rate is 3.2 times as high in Blacks and Latinxs, and 3.1 times as high in Indigenous Americans, compared to Whites [21]. In other countries, higher rates of death and infection have also been observed among people of color, which highlights the influence of structural racism on health [22]. High-quality disaggregated racial/ethnic COVID-19 data are vital to rectifying health inequities in this pandemic, yet there is a lack of standardized, up-to-date racial/ethnic data. Another limitation of our analyses is the population-level lens, which cannot account for individual-level behaviors, and our inability to differentiate the individual effects of PHSMs that were implemented concertedly in time and space. This may contribute to the weak associations observed between face mask policies and case counts. The COVID-19 pandemic has thrown societies into disorder, challenging us to rethink what characterizes a strong health system. While adequate resources and robust healthcare systems are necessary for an effective pandemic response, this analysis highlights that rapid, decisive, stringent, national, and consistent public health interventions are crucial to prevent disaster and chaos.