It has been six months since WHO received the first reports of a cluster of cases of pneumonia of unknown cause in China. Since then, the new coronavirus – COVID-19 or MERS-COV 2 – crossed the 10 million mark of reported cases and inflicted half a million deaths. With less than 5% of the world population, the United States accounted for a quarter of all the reported COVID-19 cases worldwide and deaths attributed to the virus. It is a sobering account for the world’s most powerful nation and biggest economy in nominal terms (China being the largest economy in the world in PPP terms). And the worst is yet to come, according to remarks made on June 29 by the WHO Director-General, Tedros Adhanom Ghebreyesus:
Unless we address the problems we’ve already identified at WHO, the lack of national unity and lack of global solidarity and the divided world which is actually helping the virus to spread… the worst is yet to come
Although many countries have managed to contain the spread of the pandemic, the number of reported cases and deaths continues to increase. There is now a substantial amount of data on the progress of the pandemic thanks to a host of COVID-19 trackers including the official WHO Coronavirus disease dashboard, the collaborative website Our World in Data, maintained by the University of Oxford, the COVID-19 tracking project launched by The Atlantic magazine and, last but not least, The Coronavirus Resource Center of the John Hopkins University. The New York Times has also done a very good job at reporting the latest news on the spread of the Coronavirus, from a US perspective. In addition, there are useful resources to stay updated on the latest scientific research efforts and therapeutic advances related to the Coronavirus, including The Lancet’s COVID-19 Resource Centre, the reports provided by the Imperial College COVID-19 Response Team, the information published on the website of the US National Institutes of Health (NIH) and the research and analysis updates by Institut Pasteur in France.
While there are still many unknowns regarding the development of the Coronavirus pandemic, as the world is still very much muddling its way through this plague, the available data can be used to make some useful observations and remarks.
How have different countries across the world dealt with the pandemic so far ?
Governments across the world have dealt with the COVID-19 outbreak with different measures ranging from public health recommandations to compulsory lockdowns putting entire countries on hold. Researchers from the Blavatnik School of Government at the University of Oxford have elaborated a stringency index which records the strictness of ‘lockdown style’ policies that restrict people’s behaviour and social interactions. This index is part of a broader research effort to understand how Governments responded to the COVID-19 pandemic. We have reported on the chart below the number of deaths related to the coronavirus per million of people in different countries against the evolution of the stringency index in these countries. The chart shows that, overall, there has been a ramp up in lockdown measures across the world to contain the spread of the COVID-19, since the first outbreak of this new coronavirus in Wuhan, China. But the speed and intensity of lockdown and other social distancing policies varied a lot from country to country. China for instance imposed drastic isolation measures starting from mid-February and according to the stringency index calculated by the Oxford researchers the policies undertaken by the Chinese government in relation to the coronavirus remains highly restrictive to this day. In some locations like Taiwan China and to a lesser extent in South Korea, the authorities managed to minimise the casualties from the virus avoiding outright lockdowns. The same strategy has been applied in Sweden but it did not pay off.
Conclusions should not be hastily drawn just by looking at one chart and one indicator, as there are many factors influencing the spread of the disease, and as the response of public authorities around the world has been based on upcoming data, whose accuracy has not always been satisfactory, and on their degree of preparedness to deal with such a major crisis. The experience accumulated by the East Asian countries in dealing with epidemics, going back to the SARS-1 outbreak in 2003, has helped them to react in a consistent and evidence-based way to the current crisis. Saudi Arabia has also been faced with a deadly MERS-COVID outbreak in 2009 and the Kingdom has moved quickly this year to impose stringent measures in the face of the danger presented by new coronavirus. On the other side of the spectrum, the governments in France, Italy and Spain have perhaps reacted too late to the epidemic outbreak, compared to neighbouring Germany. It is easier however to say that in retrospect, with the benefit of hindsight, than back in January-February of this year, when the information coming from China was scarce about the effective lethality and contagiousness of this new zoonotic virus.
Is there a risk of a second wave after the removal of social distancing measures?
There are mounting fears and concerns around the world that after removing the lockdown measures and relaxing social distancing restrictions, there would be a surge in new coronavirus cases, followed a few weeks later by a surge in new COVID-19 related deaths. In this regard, the situation looks particularly worrisome in the United States, where the number of new daily cases has been edging upward over the last two weeks in the Southern states. However, it is impossible to infer robust conclusions for a country as large as the US by looking only at the overall national level. As a matter of fact the United States, very much like Brazil and India for that matter, is a federal state. While the Federal government retains some general powers and can impose in some situations a national state of emergency or other measures such as border closure and travel bans between the United States and the rest of the world, the main responsibility for dealing with public health crises remains within the reams of State authorities.
Let’s look at the infection and death curves in logarithmic scale. Based on the chart below we can already make a few comments and observations:
- Some countries have not passed the peak of the first wave of the pandemic. Most prominent examples include the United States, Brazil, India and Indonesia. As I have already mentioned before, in order to draw any conclusions on how the situation is evolving in these countries it is important to look at the provincial / subnational level.
- Talking about a second wave for the coronavirus is at the least premature if not inappropriate as it would be more accurate to talk about a post-lockdown surge in the number of cases. This surge was expected as the lockdowns and the other social distancing measures were gradually being lifted. It has been predicted in the “Flatten the curve” strategy advocated by Neil Ferguson and his colleagues from London Imperial College , which has served ever since its publication end of March as a benchmark for governments all over the world. The main rationale for that strategy was not to stop the spread of the virus once and for all but to save lives, by preventing the healthcare systems from being overwhelmed by an unmanageable surge in hospitalised patients.
- The chart also shows that although the level of casualties from the Coronavirus pandemic is levelling off in many countries, as a result of the public policies and of other yet to be elucidated factors, the global fight against the spread of the virus is far from over. Hence, the warnings made by the WHO must be taken seriously by policymakers around the world.
Daily COVID-19 new cases and deaths in selected countries (log scale)
Daily COVID-19 new cases and deaths: Focus on US States and territories (log. scale)
Is the surge in new cases in some US states related to the acceleration of the epidemic or to increased testing ? Our calculations based on data from the COVID-19 Tracking Project show that ratio of positive patients out of total new tested patients has decreased or stabilised in some US states, but it has been increasing in other states. The situation must be carefully followed and monitored in in Alabama (AL), Arizona (AZ), California (CA), Florida (FL), Idaho (ID), Kansas (KS), Louisiana (LA), Montana (MT), Nevada (NV), Oklahoma (OK), Oregon (OR), South Carolina (SC) , Tennessee (TN), Texas (TX), Utah (UT) and Wyoming (WY).
Archive: Read our previous posts on the Coronavirus pandemic
We have tackled the coronavirus pandemic in three posts:
- In an early post back in March focused on the coronavirus outbreak in China we tried to put together some basic stuff about epidemics modelling by presenting the foundations of the so-called compartimental models that are widely across the world used to study the spread of infectious diseases since the 1930s. The most simple model in this class, the SIR canonical model, divides the population into compartments of susceptible (S), infectious (I), Recovered (R) individuals and analyses the transitions between these three compartments. It allowed us to introduce R0, the basic reproduction number, which is arguably the most important indicator to follow in order to describe the spread and subsequent extinction of an infectious disease.
- In a later post, we simulated the spread of the coronavirus in a hypothetical population using a compartimental model that takes into account the “network effect” – the intensity of contacts between individuals. This model allows to take into account the impact of the intervention of public authorities to stop the spread of the virus through social distanciation measures with varying levels of stringency from wearing masks in public transportation to complete country lockdowns and stay-at-home orders.
- In a third post, we elaborated on the popular “flatten the curve” strategy put forward by the governments that resorted to lock-downs, by assessing from a purely statistical point of view the efficacy of such a strategy, referring to the Richards growth model.