Analysis of different countries’ strategies for combatting COVID-19 is important to maximise the lessons learnt in a continuing pandemic. Comparison of China, Taiwan, Singapore and South Korea is likely to be particularly informative as they have faced the challenge of COVID-19 for the longest period of time and all have shown some success. Their experiences are informative although much caution is needed when generalising from the events of one country to others, which may have different patterns of transmission, differ culturally and politically, or have different health and economic resources at their disposal.
The outbreak of the new coronavirus started in Wuhan city, Hubei province. On 23 January 2020 travel was banned from that city and a national emergency response came into force.
Analyses of the outbreak in China suggest that travel bans delayed the spread of infection, but measures to prevent contact between infectious and susceptible people were more effective in limiting the number of cases. Due to effective control measures, China as a whole (population 1.36 billion) had reported only 5.7 cases per 100,000 people by 27 March.
The Wuhan travel ban came into force just before the Spring Festival holiday, which includes the Chinese Lunar New Year, traditionally a time when people travel long distances to see their families. The effect of these travel restrictions, both in China and globally, has now been investigated in several studies. Many inhabitants of Wuhan had left for their holidays by the time of the travel ban and the virus had already spread to other cities in China. The Wuhan travel ban appeared to slow the spread of infection to other mainland cities by three to five days, and to other countries by 2–3 weeks. However, even with these major travel restrictions, a large number of individuals who had been exposed to the new coronavirus were still able to travel internationally. Few were subject to quarantine at their destinations, allowing the infection to spread around the world.
As part of their national emergency response, China put in place unprecedented containment and social distancing measures. Some 65 million people in Hubei province were placed under lockdown. Those who had come into contact with infected people were sent to designated facilities for quarantine. Doors to apartment blocks were often locked and guarded. Comprehensive and widespread testing and contact tracing was introduced. Facial recognition and mobile phone data were used extensively to track people’s movements and compliance, and for contact tracing.
Analyses of the data suggest that the most effective control measures included: the early detection and isolation of cases, suspending public transport within cities, closing entertainment venues and banning public gatherings. There is evidence for the effectiveness of acting early: across China, the cities that implemented emergency control measures before discovering any cases reported fewer infections compared with cities that started control later.
By 19 March, the Chinese authorities reported no new cases as originating in China, although there were cases amongst those entering China from other countries. The challenge for China now is to prevent a resurgence of COVID-19, started by imported or overlooked local infections, and potentially amplified as transmission control measures are relaxed.
Taiwan is a holiday destination for many Chinese people during the Spring Festival, and those exposed to the new coronavirus would almost certainly have been among its visitors. Taiwan has had fewer cases per head of population (1.1 cases per 100,000 by 27 March; population 22 million) than mainland China and to date, with a mixture of control measures, has not introduced measures as severe as those used on the mainland. There continues to be a small number of new cases reported each day in Taiwan.
On 20 January, before any cases were reported, Taiwan set up a Central Epidemic Command Centre. Such a central, integrated response mechanism appears to have been important in all the countries that have effectively limited the numbers of COVID-19 cases.
Taiwan combined its national health care data with immigration databases to create automated alerts based on incoming travelers’ potential for being infected. A range of domestic public health measures were introduced: home quarantine backed by large fines for those breaking isolation orders, curtailment of mass events and a two-week schools closure program.
There is a widespread culture of mask use in Asia. Those who have colds or other respiratory infections typically wear masks to avoid spread to others, and indeed many entirely healthy people wear masks most of the time when they are out and about. This means that there are many mask manufacturers. A feature of Taiwan’s response was that it moved very quickly to ration supply of protective health masks, investing $6.8 million to create 60 new mask production lines and moving daily production from 1.8 to 8 million.
Whilst there is no evidence that mask use by the general population has any impact on transmission, rationing supply to the public, coupled with large availability of locally manufactured masks, meant that Taiwan ensured supply to hospitals and healthcare workers. This could have helped prevent the hospital (nosocomial) transmission being seen in countries struggling with supplies of personal protective equipment (PPE) for healthcare workers.
Singapore banned travel from Wuhan on 29 January and all entry from mainland China on 31 January. The government compensated individuals for days of employment lost, for example in quarantine, which in addition to reducing the impact on the individual, encouraged compliance.
Singapore has followed a policy of heightened surveillance, contact tracing and isolation. As of 27 March, schools remain open and, whilst workplace distancing is recommended, it is not national policy. The total number of cases per head of population is relatively low (5.8 cases per 100,000 by 27 March; population 5.6 million) but continues to rise slowly.
To inform the COVID-19 response in Singapore, a mathematical modelling study, based on what is known about the dynamics of influenza spread, found that a combined intervention of quarantining infected individuals and their family members, workplace distancing, and school closure (once community transmission has been detected) could keep the number of new infections to low levels. The policy lessons of this analysis, like others based on modelling, need to be drawn with care. For example, if more asymptomatic cases are infectious than is assumed in the model used in Singapore, then these control measures are likely to be less effective. As of 27 March it is too soon to be sure whether current restrictions in Singapore will maintain COVID-19 at low levels.
The Republic of (South) Korea experienced a dramatic initial increase in cases centred on one town, Daegu, followed by a smaller second wave focused around a religious sect.] The number of new cases reported daily peaked at 909 on 29 February, but has averaged fewer than 100 per day since 14 March. South Korea had reported 9,332 cases by 27 March, or 18 per 100,000 people (population 51 million).
South Korea attributes this success partly to an aggressive testing policy – around 10,000 tests per day – combined with contact tracing. South Korea did not implement population-wide lockdowns in the same way as China.
Tests for the presence of the virus are free in South Korea, including to undocumented migrants. They are available at multiple ‘pods’ in High Street locations and at airports and stations. Test results are returned within six hours via mobile phone text message.
Contact tracing made extensive use of new technology. Recognising that individuals’ recall of their contacts may be incomplete, patient interviews were supplemented with verification using mobile phone location data, credit and debit card transactions, CCTV and other data, before undertaking exposure risk evaluation. Appropriate measures, including movement restriction and symptom monitoring were then implemented depending on whether contact was close or casual.
In summary, analyses of why some countries have had fewer COVID-19 cases than others will inform the continued response to the new coronavirus around the world. Of particular interest is whether approaches to control that are less disruptive than the population-wide lockdowns used in China can be sufficiently effective. The experiences of Taiwan, Singapore and South Korea suggest that they can be, but the precise effects of each intervention, and which interventions can be applied elsewhere, are not yet clear.