/ 9 June 2020

Covid-19: Free the evidence

Safrica Health Virus
Despite the media's wish for a neat story, the African continent's response to Covid-19 is all over the map

Many science policy debates and initiatives follow a pattern. Government sceptics claim to be science sceptics and governments to varying degrees claim to be evidence-based and to varying degrees are not. I have seen this with tobacco, climate change and HIV — all of which had substantial denial lobbies.

The pattern with Covid-19 is oh so familiar — but with one big difference. Events have unfolded so fast that the gap between denial and genuine evidence-based responses is relatively clear.

In South Africa, we fall in an uncomfortable middle ground. Early on, the government clearly communicated the science of the pandemic. On April 14, the explanation by Professor Salim Abdool Karim, the chairperson of the ministerial advisory committee for Covid-19, of the strategy was a model of lucid clarity. But it went downhill from there. Without adequate detail of how the government is being informed by science, communication descended to patronising platitudes.

Open science is good science. This is not just my opinion — an increasing number of the best academic journals demand that all data, methods and computer code be available in an accessible form and this is also official South African government policy.

So why, then, are my attempts at correcting erroneous critiques of the South African approach so frequently stymied by being unable to get access to the modelling and data that is informing the government?

I give three examples of where I have been involved in interventions or tried to participate in the debate to illustrate the point.

Testing backlog

The Mail & Guardian reported a testing backlog of tens of thousands. I noted a problem weeks ago when I heard of local cases where positive results were only known after the patients had recovered. I started looking into more efficient approaches and discovered pooled testing, where multiple samples are combined into one test. There are various methods for narrowing down to identifying individual positive cases with a big saving in precious reagent and test time — in a scenario such as ours where a low fraction of tests are positive; about 3% on average around the country.

My next problem: determining whether this was in use. I made contact with a researcher in Nebraska with practical experience of the method and through a University of Cape Town contact found out that this approach has been in use in India from the start. Yet I still have no idea whether any of our test laboratories are doing pooled testing.

Contact tracing

The gold standard for stopping the pandemic is thorough contact tracing, testing all contacts of every positive case and isolating all positive cases. This not only slowed the spread of Covid-19 wherever it was done, including New Zealand, Iceland, South Korea and Germany, but also reduced the number of daily new cases. Yet as far as I can determine, contact tracing in this country still uses laborious paper-based methods.

There are numerous projects around the world to implement technology-based solutions, including some that tackle privacy concerns. Yet I have no idea whether the government is working on anything like this.

Why ventilators?

Early on, chasing ventilators was a key concern. In New York alone, the number being sought was in the tens of thousands.

From the start, I was not convinced that this was the right resource to stockpile. Each ventilator should ideally be monitored full-time by an intensive care unit nurse. ICU nursing is a skill that requires one to two years of study. How would we scale up the human side of ventilation fast enough to matter? And in any case, ventilation is not magic: many people put on ventilators do not survive.

Now the United States, still not at their peak of infections, is giving South Africa 1 000 ventilators. Do they know something we don’t? My reading of the literature and discussion with academics and medics points to other modes of respiratory support being better — and what we should be stockpiling is oxygen.

Where are we now?

I could mention other examples but the point is clear.

Although the rate of the increase in infections is nowhere near as catastrophic as it is in the worst-hit countries,  it is still growing. Local hot-spots such as the Western Cape and generally the large metros are cause for concern.

The government needs to be open. There will be crazy rumours, conspiracy theories and analysts pontificating on the basis of inadequate knowledge. Why amplify this by keeping those who do want to weigh in with evidence-based arguments in the dark?

Philip Machanick is an associate professor of computer science at Rhodes University