The 21-day lockdown that began on Friday 27 March 2020 and which places almost all of us (including dogs) under house arrest is the costliest exercise ever undertaken. As such, South Africans need to know what we are going to get out of this extraordinary investment; and what happens beyond the scheduled 21 days.

If the lockdown is largely successful (more on that later) we will be able to halt or radically slow new transmissions of the virus from those already infected with it, however many there are. Buying time is not simply postponing the inevitable.

The biology of the Covid-19-causing SARS-CoV-2 virus itself is comprehensively mapped out and there is a clearer understanding of what it does when it infects people.

Because it is so successful at finding and infecting new hosts, there is no pressure on the virus to mutate. As such, we already know that it will be defeated and brought under control. The question is how much damage it will do to us before that.

Scientists, wanting to better understand the interaction between things when there is a lot going on, sometimes do it by reducing heat (or increasing entropy) which slows the interactions and information transfers.

There is so much we don’t know but need to learn. For now, it looks like the virus is picking us off at will, but as long as you don’t move, thus not interacting with someone, you buy time and increase your odds of survival with each day that goes by.

One can show that the analysis is correct. If you track just about anything to do with the virus, anything older than a week is much less valuable than an equivalent (authority-wise) report or article more recent than that.

Right now, our problem is that, as the virus’s transmission rate is exponential, all the data we are getting is also increasing exponentially and it becomes harder, not easier, to make sense of it. Instead, what we are stuck with is very “noisy” information. Slowing down transmissions allows us to separate the useful signals from the noise or that which distorts the signal we need to make the right decisions.

Over the next three weeks, we are likely to get much better information on the following:

1. Factors that make people sick and the mortality rate: 

Obviously, the prospect of dying from Covid-19 concentrates our collective minds. It is not just the prospect of dying, those who have died have needed intensive medical attention, including — for most of these victims — the need for ventilators (intubation) and full ICU treatment as well as suitably trained medical staff. Even the majority of cases classed as mild and not requiring medical intervention can be pretty awful.

At Ground Zero, the city of Wuhan, the early fatality rates appeared quite high with 3-4% mortality, whereas the rate in the rest of China is around 0,7% (lower if you exclude Hubei province where Wuhan is situated). If data provided by the Chinese authorities is correct, the highest death rate was during the initial outbreak and, of all the Chinese who succumbed, the vast majority were older than 70 and, as is typically the case, many of these patients had other underlying health conditions.

There were several anomalies too. Some much younger and healthy people, particularly those in the frontlines of the health system, also got very sick and some died. Among them, 34-year-old Dr Li Wenliang, who first raised the alarm on the outbreak and who was subsequently targeted by the Chinese state for spreading false rumours.

What we do know is that the Chinese government, once aware of the potential scale of the problem, instituted and enforced a very strict lockdown.

It also embarked on a programme of comprehensive testing. Famously, it built a hospital in 10 days. The lockdowns slowed the infection rate, which meant less pressure on health systems. In addition, treatment protocols (like the way sick patients should lie in bed) developed in the early stages appeared to have an impact.

The Chinese experience taught the world a little about the co-morbidities (existing underlying diseases) present in the majority of the disease’s victims, but did not fully answer the relatively high fatality rate in otherwise young and healthy frontline healthcare workers (like Dr Li) who are very exposed to infection.

Something similar is happening to healthcare workers on the frontlines of treating the disease around the globe. One suggestion is that Covid-19 is more dangerous for people with weaker immune systems. Healthcare workers who work ridiculously long shifts for days on end under conditions of great stress physically and emotionally have reduced immune systems which exposes them to Covid-19. In short, being highly stressed and tired could well be another comorbidity that increases your chance of getting really sick.

We should know that, if Chinese figures are correct, the rates of people getting critically ill and dying are nine to 10 times higher than that of normal flu.

That will put unbearable strain on our health systems and frontline health workers. They will have to make multiple triage decisions which probably amount to sacrificing older patients in favour of younger ones. For doctors and nurses whose purpose and training is to save lives, this is pure hell and it goes on for weeks, perhaps longer.

While the rest of us applaud their sacrifice, we might want to put strict measures in place to reduce the relentless stress and fatigue they will experience and perhaps think about the age of the doctors and nurses we deploy to the frontline. Pointless Gallipoli-like sacrifice is not going to help the health system cope any better.

The experience in the subsequent Covid-19 epicentres of northern Italy and Spain’s two biggest cities have provided further information on the profile of patients and the main co-morbidities, but also something about the dangers of a poorly enforced lockdown that comes too late.

What Italy does show us though is that a poorly enforced lockdown is better than none at all.

As the disease spreads around the globe, we are sure to get much better information, particularly from smaller and richer countries with well-functioning health systems.

Of particular interest is Switzerland. As of 26 March, the country had the world’s second-highest per capita rate of positive coronavirus cases (at 988 cases per million people) and, at that date, 237 people had died. As one might expect, the canton hit hardest is the Italian canton Ticino, bordering Italy’s Lombardy state but, taking confirmed cases into account, it would appear that Covid-19 is twice as likely to kill patients in French-speaking cantons of Switzerland than in German-speaking ones, and more than twice as likely to kill patients in Italian-speaking cantons than in French ones.

Once again, there may be measuring anomalies at play that may become clearer when there is more testing for infections, including from the healthy population, but we might learn about cultural factors that might spread the disease. Perhaps there are genetic factors at play?

Germany itself, with a relatively high number of infections, has only recorded six deaths per 1,000 infected patients. Norway, with one of the higher number of known cases in proportion to the total population, has recorded just five deaths per 1,000 infected patients. Both Germany and Norway have some of the highest testing rates in the world.

While being old generally means having one or more co-morbidities that make one particularly susceptible to getting sick and dying from, or as a result of, contracting Covid-19, South Africans who, on average have high rates of the identified co-morbidities irrespective of age (together with HIV and TB) will want to know what are the likely decisive factors. Some indication of this might emerge in the next few weeks.  

2.   The likely infection rate

Up until now, most available information about the disease is from confirmed cases or people who have shown some of the symptoms. In primary school maths terms, we have only examined the numerators. But what of the denominator?

Some countries have conducted widespread testing, but these have tended to focus on likely cases. Proper comprehensive testing, including those who are asymptomatic and who perhaps never even get sick, would allow us to get closer to the real infection rate.

The outcomes of greater testing in Switzerland will certainly render some useful information.

But Iceland is particularly interesting. The tiny country of just 340,000 people has already tested 3,5% of its population and not just people with Covid-19 symptoms, but all arrivals in the country since February. In addition, anyone wanting a test can get one. And Iceland has now started to conduct random testing to check the true spread of asymptomatic carriers of the virus.

Around half of all carriers appear to be asymptomatic. This high rate of asymptomatic carriers was confirmed by a study undertaken in the small village of Vo, where all 3,000 residents were tested. There, asymptomatic carriers amounted to between 50-75% of all those who had been infected. On one level, this is encouraging. Covid-19 is far less deadly than we had thought but, from a public health point of view, it is horrible. Those who are susceptible to getting very sick are being stalked by carriers oblivious to the fact that they are healthy and spreading the pathogen.

3.   The efficacy of treatments

The development of new drugs to combat a disease generally takes years and the record of the pharmaceutical sector in developing new drugs in recent times has been disappointing. Researchers are now looking at existing drug treatments developed for other diseases that might be useful. Outbreaks of Covid-19 overwhelm a health system and are not conducive to organising clinical trials. Successful lockdowns or programmes to limit infection rates reduce the number of patients needed for trails.

Standard protocols for drug trials are now in place and this is important because it replaces multiple small, inadequate studies. Working collaboratively produces a scale which allows detection of drugs that might have small, but still significant, benefits or benefits for just certain types of patients. South Africa is a participant in the search for effective treatments.

Getting this right is important as it reduces the scope for opportunists to “trumpet” untested cures. At present, there appear to be three approaches to drug treatments. Antivirals such as those used to combat HIV/AIDS and antimalarials such as chloroquine; anti-inflammatories that could treat lungs; and antibody-based treatments, derived either from recovered Covid-19 patients (or developed in labs) to be given to the seriously ill or as a temporary prophylactic for healthcare workers.

The other issue is preparing hospitals and clinics to be better prepared to treat the expected rush of patients suffering from Covid-19. In this respect, South Africa’s system is already over-stretched and this must have played a big role in the decision to implement the lockdown earlier.

A few things should be done immediately. Firstly, we need far more personal protective equipment (PPE) especially N-95 compliant masks for our healthcare workers. One controversial proposal and something being trialled in New York is ventilator splitting, where one ventilator is used for more than one patient.

South Africa itself has a very low mortality rate (for the moment) but this might be something to do with the profile of those infected.

4.   The efficacy of lockdown/quarantines and testing

The lockdown regulations that the South African government chose to impose are some of the toughest anywhere in the world. They have generated considerable criticism not least because they make the already hard lives of many living in townships — and especially informal settlements — even harder. It is likely that the regulations are mostly unenforceable and there is little capacity to force compliance.

To be a little charitable, it is hard to imagine how regulations that have to apply to everyone from Houghton to Alexandra, Constantia to Khayelitsha could be anything other than unfair or arbitrary. Perhaps the regulations were directed at the suburbs and the middle class because, from a press release from the Western Cape government, that appears to be where almost all the positively identified cases seem to be. It is likely that the main effort is about keeping the virus out of the communities.

By the end of the lockdown period though, South Africa will have had the opportunity to see how other countries have fared. In this regard, the experience of different cities, counties and states in the US will be particularly useful. The measures implemented by other developing countries will also be clearer. One rather unusual process in Brazil is where drug gangs and not the government in the favelas are involved in enforcing physical distancing in the absence of government action.

Obviously, the lockdown cannot continue indefinitely but should the lockdown in South Africa succeed in slowing the spread, we, more than others, have a chance to slowly open up and start to relax restrictions.

South Africa is in this position firstly because the lockdown occurred early in the process of exponential growth of infections, but also in the under-appreciated amount of testing that has in fact occurred. At more than 31,000 tests, South Africa has tested vastly more people than most other countries at the same stage of their infection curves.

If you have new infections under control and you can test, track and trace those who have been infected or have interacted with infected individuals, regulations can be lifted and more regular economic activity can start up again.

In a back-of-envelope modelling study done by former World Bank and Nobel Prize-winning economist Paul Romer, the value of widespread testing is made evident. To keep the total infected population below 20%, Romer calculates that if 7% of any population were tested on any given day, the resultant taking and tracing would mean less than 10% of the population would have to be in lockdown at any point in time. Without testing, over 50% of the population would have to be quarantined to achieve the same result.

No country is near the daily 7% testing rate yet and that would be impossible to do despite the excellent ramp-up in testing seen so far, but much cheaper tests (even if somewhat less accurate) are just around the corner.

The lockdown is going to be very hard for all South Africans and many of us must be incredibly anxious about whether we will have jobs or even just a functioning economy after the lockdown is eased. We should remind ourselves that what we are doing is investing in time itself.

Time is far more valuable to humans in this battle than it is for our nano-scale adversary.

Human beings, being totally unprepared for the attack, win probability benefits within the time dimension. Our learning about how to defeat the virus is convex to time as we learn more — the virus can only do what it does.

Each day that goes by with the spread of the virus contained, we benefit exponentially and in multiple dimensions. DM