President Cyril Ramaphosa has been widely praised for his decisive leadership in locking down the country on Thursday last week, while Covid infections were still below 1 000 and no deaths had yet been reported. His quick action in helping to ‘flatten the curve’ was broadly commended, whereas UK prime minister Boris Johnson’s delay in implementing a lockdown has often been pilloried in the press.

If South Africa’s Covid curve can indeed be flattened through the lockdown – despite the practical obstacles to effectively isolating the millions living in teeming townships and informal settlements – this will help give the health system time to prepare.

The country can use the lockdown period to set up makeshift field hospitals in empty schools, town halls, hotels, and conference centres; to bring retired doctors and nurses back to work; to boost supplies of masks and protective equipment for health workers; to acquire as many ventilators (or simpler respirators) as can be made or otherwise marshalled. And so on.

The more such steps are taken, the more lives are likely to be saved as the virus spreads and the vulnerable fall gravely ill. But the drastic step of locking down South Africa’s economy – and thereby helping to trigger a 5% (or more) contraction in GDP this year – needs to be based on the best available data about the dangers of Covid-19. That, in turn, is best derived from comprehensive testing and accurate recording and analysis.

Many difficulties

Covid-19 death rates are generally computed by comparing the number of virus-related deaths with the number of known cases. However, writes Dr John Lee, a retired UK pathologist, in a recent issue of Spectator magazine, there are many difficulties in gathering and interpreting the necessary data – even in a well-resourced country, such as Britain.

In Britain, testing has mostly been carried out in hospitals among patients with significant symptoms. Few tests have been carried out among the general population. Iceland, by contrast, has tested a wider proportion of its population than any other country – and has found that about half of those who test positive for Covid-19 have no symptoms at all. Most of the rest have only minor symptoms.

This data suggests that many people in the UK might also have contracted the virus without realising it.  If this is so, the real number of Covid infections in Britain could be ten or 20 times higher than the UK’s current test results show. That, in turn, would mean that death rates could be ten or 20 times lower.

In late March, when Dr Lee was writing, the UK had 1 019 deaths and 17 089 confirmed cases, giving an apparent death rate of 6 per cent. But if the number of infections were ten or 20 times higher, that would put actual death rates far lower: at 0.6% or 0.3%.

Respiratory deaths

Problems are also evident in the way Covid-19 deaths are recorded. As Dr Lee points out, when people die of respiratory diseases in the UK, this is generally not recorded. Doctors do not test for flu or other seasonal infections, and ‘the vast majority of respiratory deaths are recorded as bronchopneumonia, pneumonia, or old age’. If the patient has another illness, such as cancer, ‘this will be recorded as the cause of death, even if the final illness was a respiratory infection’.

But Covid-19 has been treated differently. It has been listed as a notifiable disease, so when a patient who has tested positive dies, Covid-19 must be recorded on the death certificate. Yet ‘this is contrary to the usual practice for most infections of this kind’.

Adds Dr Lee: ‘There is a big difference between Covid-19 causing death, and Covid-19 being found in someone who died of other causes. Making Covid-19 notifiable might give the appearance of it causing increasing numbers of deaths, whether this is true or not. It might appear far more of a killer than flu, simply because of the way deaths are recorded.’

Recent data from Italy illustrates the importance of this factor. Italy’s Covid-19 fatality figures include all those who have died in hospitals with coronavirus. But Professor Walter Ricciardi, scientific adviser to Italy’s health minister, has recently elaborated on what the figures mean. On a re-evaluation of the data, he writes, ‘only 12 per cent of death certificates have shown a direct causality from coronavirus, while 88 per cent of patients who have died have at least one pre-morbidity condition – many had two or three’.  In simpler terms, 88% of these patients did not die from the virus, despite being infected by it.

No major deviation

Dr Lee notes further that a lethal new disease would generally push up death rates to a significant degree. Covid-19, however, has thus far had little such impact. Britain would normally expect some 46 000 deaths in the first 28 days of March. Against this figure, the 1 019 Covid-related deaths recorded – many of which may not have resulted directly from the virus – are not a major deviation.

The huge database assembled by the Johns Hopkins Coronavirus Resource Centre – which updates Covid-19 data from all over the world on a daily basis – poses yet another conundrum.  As Dr Lee notes, ‘this data is not standardised and is probably not comparable, yet this important caveat is seldom expressed in the many graphs we see. It risks exaggerating the quality of data that we have.’

Testing in Britain and many other countries is far advanced compared with what South Africa, with its limited resources, has thus far been able to achieve. Here, the National Health Laboratory Service (NHLS) has been testing about 5 000 samples a day, which means the test data available is still very limited.

The NHLS plans to expand its testing capacity to 36 000 samples a day by the end of April. In addition, the government will soon be sending some 10 000 field workers into villages, towns, and cities to screen people for coronavirus symptoms.

Those with identifiable symptoms will be sent to local or mobile clinics for testing, but asymptomatic individuals are likely to be missed. The many other difficulties in assembling accurate data, as earlier outlined, will doubtless also continue to apply.

Lower than first thought

That the Iceland data, for example, shows that the great majority of infected people have zero or minor symptoms should comfort all those living in fear of the virus. So too should the further data from Italy, indicating that the deaths resulting directly from the virus are much lower than first thought. But that the data on which drastic lockdown decisions are being made is so incomplete and uncertain is a cause for deep concern.

With Covid-19 fears rising rapidly, many governments have understandably decided that total lockdowns should be implemented as quickly as possible to limit fatalities. But lengthy lockdowns have crippling economic and social consequences, which makes them difficult to implement or sustain.

Very much more comprehensive data – which needs urgently to be assembled and analysed – could, however, offer a way out of this Hobson’s choice.

If that data confirms that most infected people have no or minor symptoms, that herd immunity is further advanced than earlier anticipated, and that death rates from the virus, as in Italy, are very much lower than initially believed, then public fears would diminish. This could open the way to lifting lockdowns, while deploying targeted mitigation measures to help protect the people most at risk.

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