COVID-19, caused by SARS-CoV-2, was first identified in Wuhan, Hubei Province, China, in December 2019 [1]. Since then, it has spread around the globe including to every country in the East Asia and Pacific region, severely straining governments, health care systems, economies, and quality of life globally (Figure 1). East Asia and the Pacific, as defined by the World Bank, consists of American Samoa, Australia, Brunei Darussalam, Cambodia, China, Fiji, French Polynesia, Guam, Hong Kong, Indonesia, Japan, Kiribati, People’s Democratic Republic of Korea, Republic of Korea, Lao People’s Democratic Republic, Macao, Malaysia, Marshall Islands, Federated States of Micronesia, Mongolia, Myanmar, Nauru, New Caledonia, New Zealand, Northern Mariana Islands, Palau, Papua New Guinea, the Philippines, Samoa, Singapore, Solomon Islands, Thailand, Timor-Leste, Tonga, Tuvalu, Vanuatu, and Vietnam [2]. Not all of these countries collect or report COVID-19 caseloads and deaths, such as North Korea. As of October 28, 2020, the World Health Organization (WHO) reports a total of 43,540,739 cases and 1,160,650 deaths in these countries [3]. This global region encompasses countries of diverse income levels, political systems, cultures, populations, geography, climate, and health care systems, factors which have profoundly influenced not only the effects of the virus but also the response of each member country.

The extreme quarantine implemented in Wuhan and the entire Hubei region of China mandated all residents to shelter in place without exception [4]. Wuhan imposed travel restrictions in and out of the city in addition to canceling gatherings, closing public places, and shutting down schools and universities [5]. China allocated significant resources for public health service and epidemic prevention and control [6].

The prompt response by East Asian countries was informed by the 2003 severe acute respiratory syndrome (SARS) and 2015 Middle East respiratory syndrome (MERS) outbreaks [7,8]. Singapore and Vietnam’s strategy of comprehensive surveillance to detect and contain as many cases as possible has been highly successful in controlling or eliminating SARS-CoV-2 [9,10]. Taiwan’s response to the 2003 SARS epidemic also informed COVID-19 response [11,12]. The Taiwan Centers for Disease Control aggressively traced confirmed cases while the government distributed masks and personal protection equipment [13,14]. Taiwan’s interconnected public health, medical, and insurance infrastructure reduces barriers to doctor appointments and follow-up visits, allowing their health care system to capture more cases. Furthermore, their single-payer model allows for centralized health records of population-level longitudinal data, a valuable tool for analyzing the spread of the pandemic [11].

South Korea was the hardest hit country outside of the Middle East during the MERS outbreak in 2015, prompting the Korea Centers for Disease Control (KCDC) to prepare for the next infectious disease outbreak [15]. When COVID-19 breached Korea’s borders, the KCDC actively performed contact tracing, quarantined exposed individuals, and diagnosed and isolated new cases with rapid and extensive testing [16-19].

New Zealand eradicated COVID-19 by introducing some of the strictest lockdown measures early on, allowing the government to pursue an elimination approach rather than the typical, mitigation-based model of pandemic planning. Schools and nonessential workplaces were closed, social gatherings banned, and severe travel restrictions applied [20-22]. Australia implemented similar though somewhat less stringent lockdown measures and border closures, resulting in substantially lower crude case fatality and hospitalization rates than many other high-income countries [23,24].

Some low- to middle-income countries such as Vietnam and Mongolia have also been able to implement successful responses to the pandemic despite limited resources or shared borders with China. As a result of Mongolia’s travel restrictions, lockdown measures, and surveillance of active infections, they reported no confirmed cases until March 10, 2020, and no intensive care admissions or deaths until July 6, 2020 [25]. Vietnam responded immediately to its first cases by activating an emergency prevention system involving intense surveillance, quarantine, and contact tracing. Those who broke social distancing measures were severely punished. As of July 8, 2020, the nation had the highest test per confirmed case ratio in the world [26-31]. This approach differs vastly from the widespread testing strategy employed by South Korea, which, although seen by many as a best practice in fighting the pandemic, is more resource intensive [32].

In contrast, the Philippines has become Southeast Asia’s coronavirus hotspot, overtaking Indonesia with a caseload exceeding 360,000 people with nearly 7000 deaths and no coherent strategy for defeating the virus [33]. Although their first case was reported in January 2020, a national lockdown was not enacted until March, and when citizens took to the streets to protest a lack of food and supplies 2 weeks later, President Rodrigo Duterte threatened that the police and military would shoot those who did not comply with stay-at-home orders [34-36]. Once the lockdown was lifted in June, cases quickly began to climb again. In addition, the Philippines was late to initiate COVID-19 measures including testing, isolation, and contact tracing [33]. Their result paralleled the United States with a similar outcome. The first wave is still raging through the islands while the second wave commences around the globe [37].

The Pacific Islands have been some of the least affected nations in the world due to their unique ability to shut down border traffic [38]. As of August 2, 2020, only 6 countries of the Pacific Islands (Papua New Guinea, Fiji, French Polynesia, Guam, New Caledonia, and Northern Mariana Islands) have recorded positive COVID-19 cases. Among the 12 countries without any confirmed cases, 10 are in this region (Kiribati, Marshall Islands, Micronesia, Nauru, Palau, Samoa, Solomon Islands, Tonga, Tuvalu, and Vanuatu). Furthermore, many nations recently strengthened their infectious disease prevention, surveillance, and response systems due to the re-emergence of measles in the area in 2019 [38-40].

The East Asia and Pacific region encompass a wide range of health care systems with varying capacities for pandemic preparedness. In New Zealand, approximately one-fifth of the government’s spending goes to the health sector, and health services are either free or heavily subsidized [41]. In contrast, some of the world’s smallest, least developed, and most isolated nations in need of health system strengthening are in the Pacific Islands region [42].

In the Philippines, 43% of the urban population lives in slums, and people living in densely populated urban slums are unlikely to have the space or economic means to practice social distancing [43,44]. The majority of Filipinos pay out of pocket for health care, a prohibitive cost that disproportionately affects the country’s 7.5 million senior citizens, many of whom live in rural areas [45]. These barriers to access are exacerbated by the fact that hospitals in the Philippines are currently overwhelmed and reaching maximum capacity [45].

In Cambodia, more than 3 million people lack access to safe water, and 6 million lack access to improved sanitation. This disproportionately affects rural communities, where approximately 77% of Cambodians live, placing them at greater risk from the pandemic [46,47].

Meanwhile, the pandemic has added an additional layer of complexity to Indonesia’s longstanding problem of food insecurity and reliance on food imports. In 2018, 55% of the Indonesian population experienced moderate or severe food insecurity. Unemployment and other loss of income associated with the pandemic have likely exacerbated this problem, with 70% of low-income households reporting a loss of income and about the same proportion reporting shortages of some foods or not eating as much as they should, placing 24 million children at risk of food insecurity [48].

Myanmar has attempted to combat the aggravating effects of food insecurity on its already underfunded health sector by providing emergency rations through strategies such as community-based food banks [49,50], although 10%-15% of the population report consuming reduced quantities of nutritious foods [51].

Individuals with underlying medical conditions are also known to be at greater risk of COVID-19. In Australia, Indigenous Australians constitute a uniquely vulnerable population due to the increased prevalence of diabetes and respiratory and cardiovascular conditions, as well as high reported smoking rates [52,53]. China is notorious for having the worst air pollution problem in the world, which may correlate with susceptibility to respiratory infections [54-56].

Despite early exposure, a high population density, an aging population, and little social distancing measures, Japan reports low rates of infection and death from COVID-19 [57,58]. This has led to some hypotheses that the Bacille Calmette-Guérin (BCG) vaccine against tuberculosis may protect against the virus, as countries that mandate the BCG vaccine have relatively low per capita death rates from COVID-19 [57,59].

Tourism is an important source of revenue for many economies in developing Asia and the Pacific [50,60,61]. For countries like Palau, where international tourism receipts are close to 50% of the GDP (gross domestic product) and over a third of international tourists are from China, the decline in tourism due to COVID-19 has been devastating [60].

China is a major trade destination for many developing Asian economies such as Mongolia, the Philippines, Singapore, Taipei, and Vietnam [60]. Long quarantine-like conditions have the potential to deeply harm export-based economies such as Mongolia, where coal exports were reduced due to border restrictions [25].

While Western cultures endorse individualism and a more independent self-concept, Eastern cultures emphasize collectivism and a concept of the self as interdependent with others, which may motivate individuals to remain committed to COVID-19 precautions even at the expense of personal freedoms [62]. Some of the actions that have enabled Asian countries to contain the spread of the virus have been challenging to Western notions of privacy and individual freedom; such measures have been almost universally accepted in Asian countries [26,32]. Therefore, interpersonal transmission of the virus may be less likely in East Asian countries [63].

Public health departments, as well as universities and media outlets, are tracking the novel coronavirus using raw data, including the number of new infections, testing, positivity, R₀ (reproduction number), deaths, local hospital capacity, etc [39,64-93]. Public health surveillance informs policy on “flattening the curve” of COVID-19 [94-97]. Epidemiologists have utilized various modeling techniques to forecast the numbers of cases and deaths attributed to the virus [98-102]. Both the WHO and the Center for Systems Science and Engineering at Johns Hopkins University have developed tracking tools [98]. While helpful, these static metrics suffer from incomplete case ascertainment and data contamination [94,96]. Existing surveillance is a proxy for the true coronavirus caseload because public health surveillance systems tend to pick up the most severe cases [103,104], which is especially problematic when tracking SARS-CoV-2 because most carriers are asymptomatic, presymptomatic, or only have mild symptoms [105-108]. Public health surveillance that can control for these limitations are needed. Moreover, metrics that detect how transmission speed of the novel coronavirus, shifts in the pandemic, acceleration in speed, and persistence of COVID-19 based on prior infections are needed to supplement existing measures [83].

The objective of our research is to use a longitudinal trend analysis study design in concert with dynamic panel modeling and method of moments to correct for existing surveillance data limitations [94,96]. Specifically, we will measure significant weekly shifts in the increase, decrease, or plateaued transmission of SARS-CoV-2. Our study will measure the underlying causal effect from last week that persists through this week, with a 7-day persistence rate to explain a clustering/declustering effect. The 7-day persistence rate represents an underlying disease transmission wave, where a large number of transmissions that resulted in a large number of infections today then “echoes” forward into a large number of new transmissions and hence a large number of new cases 7 days later. If positive, it is consistent with, for example, a mega-event (eg, the large religious gathering at Daegu’s Shincheonji Church of Jesus in South Korea) that causes an increase in the number of cases in adjoining days, among other explanations [16]. If zero or nonsignificant, it is indicative of a constant rate of new infections and/or a constant size of the infectious population. In summary, we will measure negative and positive shifts in the transmission of SARS-CoV-2 or acceleration/deceleration rates that are not limited by sampling bias.

Regression results are presented for 26 East Asian and Pacific countries in Table 1. Weekly surveillance data in Tables 2-6 and Figure 2 [117] are based on these regressions.

The Wald statistic for the regression was significant (χ²₅=49,836,424; P<.001). The Sargan test was not significant, failing to reject the validity of overidentifying restrictions (χ²₂₉₄=18; P=.99).

Table 2, for the week of October 5-11, and Table 3, for the week of October 12-18, present traditional surveillance metrics including new COVID-19 cases, cumulative COVID-19 cases, 7-day moving average of COVID-19 infections, infections per 100,000 population, deaths, cumulative deaths, and 7-day moving average of deaths rates per 100,000 population. Overall, in East Asia and the Pacific, by the second week, there were 9951 new daily cases of COVID-19, 1,076,042 cumulative cases of COVID-19, a 7-day moving average of 8005, an infection rate per 100,000 population of 0.4344, 216 daily deaths, and 28,053 cumulative deaths.

For the week of October 5-11, Indonesia led the East Asian and Pacific region with the highest number of new cases at 4294, followed by the Philippines at 2156 and Myanmar at 2158. The number of deaths follow the same pattern for Indonesia, the Philippines, and Myanmar at 88, 86, and 32 deaths, respectively.

For the week of October 12-18 (Table 3), Indonesia, the Philippines, and Myanmar continued to lead the region with 4301, 2588, and 1287 new COVID-19 infections and 84, 72, and 39 deaths, respectively. The cumulative number of deaths for the region reached 28,053 by the second week in October.

Tables 4 and 5 provide the novel surveillance metrics for the weeks of October 5-11 and October 12-18, respectively. During the week of October 5-11 (Table 4), French Polynesia had the highest speed or velocity of new cases at 37 per 100,000 population, followed by Guam at 32.6 cases per 100,000 population. The highest rates of acceleration per 100,000 population was 0.312 for Myanmar, 0.025 for Malaysia, and 0.015 for Indonesia. The highest jerk rates were 0.228, 0.027, and 0.008 for Myanmar, Indonesia, and Japan, respectively. French Polynesia and Guam ranked 1 and 2 for 7-day persistence at 28.68 and 25.14, respectively, meaning these cases were statically attributed to those persons infected 7 days earlier.

Table 5 presents the novel surveillance metrics for the second week of our study period. Between October 12 and 18, French Polynesia ranked first in speed of new infections at 56.5 per 100,000, followed by Guam at 46 per 100,000. French Polynesia and Guam are several standard deviations higher than the rest of the East Asian and Pacific region. French Polynesia had the highest acceleration rate at 3.17 per 100,000 population, and Polynesia had the highest positive jerk at 15.4 per 100,000 population. French Polynesia and Guam had the largest 7-day persistence during the October 12-18 period (Table 6). In summary, French Polynesia, Malaysia, the Philippines, South Korea, and New Zealand have positive speeds, acceleration, jerks, and 7-day persistence, indicating an upwards shift in the pandemic.

The most populous countries in East Asia and Pacific include China, Indonesia, Japan, Philippines, and Vietnam (Table 7). Countries with larger populations are at risk for having more COVID-19 infections by virtue of size, but this was not necessarily the case when comparing population size to the speed, acceleration, jerks, and 7-day persistence in Tables 4 and 5.

For comprehensive surveillance of static or traditional surveillance metrics with novel surveillance metrics for East Asia and Pacific, see Multimedia Appendices 1-3.