HONG KONG: The amazing effectiveness of modern transport systems has been essential for global economic development and made a major contribution to vastly improved lifestyles, compared with 50 years ago.
But the downside has been the resulting enormously increased rapidity of infectious disease spread locally as well as globally.
This was demonstrated during the H1N1 epidemic in 2009 which spread to 74 countries from May to June that year. The novel coronavirus has also brought this challenge to the fore.
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For this reason, reducing the amount of movement is critical for slowing down spread of an infectious disease.
Therefore, purely based on epidemiological considerations, the lockdown of a city that can become a source of infection for other parts of the country or beyond can be an important component of a disease emergency response strategy.
A VERY CHALLENGING DECISION FOR AUTHORITIES
China has slapped extraordinary lockdowns on Wuhan and nearby cities, effectively curbing all movement of over 50 million people between urban centres.
A similar fate possibly awaits more cities, after Taizhou, just 175km away from Shanghai, was placed under lockdown this week. Train services between many cities have also been suspended.
Restrictions have also been placed on people movement within cities. In some places, such as Wenzhou, 800km from epicentre Wuhan, businesses and schools have been closed for weeks, and citizens have been asked to stay confined at home.
Chinese citizens and travellers who have been to Wuhan recently are tracked and quarantined all across China. Many foreign visitors and nationals have been evacuated.
How effective are such city-wide lockdowns? Unfortunately, it is never that simple when we are dealing with human beings. People, who may be unwitting carriers of the illness, will try to circumvent the lockdown, and make escape attempts through means outside of official border controls.
Authorities will have to mount a major enforcement effort to tackle unauthorised movements in and out of cities. The larger the population, the more difficult enforcement can be.
The decision whether to lock down cities needs to consider the risk, consequences, and different intervention scenarios.
What proportion of the population are likely to become mildly ill, seriously or die from the disease, and how does that compare with other common causes of disease?
How will economic activity be affected by a lockdown? Will it significantly disrupt supply chains to and from the city, not just in medicine, food and other commodities for Chinese citizens but also those which may be critical parts of chief global supply chains?
The knock-on effects could be huge. For many countries, China is a key producer, supplier and manufacturing centre for major goods and services.
This is the key challenge for authorities - to weigh up the relative importance of these different impacts, and to make a judgment call based on proportionality.
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But the problem is that these decisions are particularly tricky during the initial phase of an outbreak when, often, very little is known about the epidemiology of the disease and decision-makers have to feel comfortable in dealing with the resulting uncertainty.
Authorities must also consider the need to project confidence and show effective leadership to the general public.
The Chinese government had to deal with this dilemma in early to mid-January, compounded by incomplete, premature and misleading epidemiological conclusions from the early phase of the outbreak in Wuhan.
In fact, it appeared at the time that the source of the outbreak had been identified and controlled, and that there was no human-to-human transmission based on the fairly substantial number of contacts that the still very small number of known infected people had.
THE SITUATION TURNS
But by Jan 22, after five Chinese provinces reported additional infections and the World Health Organization (WHO) announced an emergency meeting to decide if the outbreak constituted an international health emergency, the Chinese authorities shifted gears and announced a lockdown of Wuhan.
Large-scale events like the Wuhan Olympic boxing qualifying tournaments were cancelled.
By that time, several million people seem to already have left Wuhan for various reasons, including family visits associated with Chinese New Year.
With 20/20 hindsight, if the lockdown had happened a few weeks earlier, it might have been possible to substantially curtail the epidemic, such that all available emergency resources of the country can be focused on Wuhan, rather than have to deal with a spread to almost the whole country.
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But it needs to be recognised that it was rather impressive how quickly and seemingly effective the Chinese government was able to implement the city lockdowns and the other facets of the novel coronavirus emergency response policy, and, as importantly, make the necessary staff, equipment, consumables and financial resources available– including the building of a hospital in a week.
CITY LOCKDOWNS WERE NECESSARY
It is too early to say whether the positive impacts of city lockdowns outweigh the negative ones, but basic epidemiological principles suggest they were needed.
Unfortunately, we do not have recent historical experience with city-wide lockdowns during disease outbreaks to compare with.
Recent experience has been with terrorism-related shutdowns, most notably in 2015 when the Belgium government imposed a security lockdown on Brussels based on intelligence of an impending terrorist attack.
London also imposed partial terrorism-related lockdowns on specific neighbourhoods in 2019 and 2020 but these lasted only for hours.
So, there is no precedent for this infectious disease lockdown in Wuhan. Lockdowns are a very strong and invasive intervention, particularly when it comes to cities as large as Wuhan with its 11 million inhabitants.
But this outbreak occurred in a country that has 1.4 billion citizens with one of the most advanced transport networks in the world connecting millions of people living highly clustered in a number of megacities.
When SARS occurred in 2003, the world was not as connected as it is now. China’s transport network was not as efficient as it is now.
When the H1N1 outbreak occurred in 2009, we were closer to where we are now in terms of connectivity, but China has made further advances since then in transport infrastructure development.
It is still too early to say whether the city-wide lockdown of Wuhan and other cities across mainland China achieved the desired impact, a conclusion we might only be able to reach after this epidemic is over, comparing the observed dynamics of this virus with different hypothetical interventions using mathematical models.
LOOK FOR LESSONS FOR FUTURE OUTBREAKS
It is essential for us as a global community to not only see the very important need for a rapid and effective emergency response, but to also realise that it is an essential learning opportunity for prevention and control of future outbreaks.
If it is not utilised to its maximum potential, we may well fail in managing a future infectious disease outbreak that might then be caused by a highly transmissible pathogen resulting in high levels of human mortality, which luckily the novel coronavirus does not seem to be.
With each previous event, we have learnt and become better at managing the outbreak. But I do wonder whether we are learning too slowly.
Our ability to prevent and manage emergencies is not keeping pace with the ever increasing efficiency of our transport networks and increasing urbanisation. Both, provide ideal conditions for an infectious pathogen that could result in a “perfect storm”.
So far, efforts have focused on containment but more needs to be done to develop a real-time operating picture of the disease in the early stages. There are lessons to be learnt not just about scientific understanding of disease spread and available tools for control but also about information flows and decision-making processes and coordination, between national and local authorities.
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This includes technical capacity of local and national staff in the required scientific disciplines (including human and veterinary medicine, microbiology) as well as economists and anthropologists, and their ability to work together in interdisciplinary teams.
There also needs to be an effective interface between these scientific experts, who may be employed in government, universities or at research institutes, and the policy-makers.
That effective communication needs to be established and tested before the emergency, since it is too late to have to learn to trust and work with each other during the very tense times of an actual emergency.
The content and format of communication to the public should be informed by specialist experts in risk communication. If that is not the case, the consequences can be unpredictable and may result in loss of public trust.
Dirk Pfeiffer is Chow Tak Fung Professor of One Health at the City University of Hong Kong.