It’s time for mass-testing

| March 31, 2020

As the coronavirus contagion unfolds, we are seeing patterns that should be emphasised. The novel coronavirus is now affecting 192 countries and there are nearly 425,000 cases. More than 295,000 cases are active and this means there are probably more than a million infections. Yet the news is not all bad. The data reveals how to fight the virus.

The data across 192 countries raises two issues. First, is there is a uniform curve of contagion or does each country have a different curve? In other words, are there country-specific factors that are affecting the spread of this virus? The data suggests there are.

Second, the data shows the virus is more successful than other viruses because it hides better. Those without symptoms or with mild symptoms are driving the virus: 95 per cent of current active cases have mild symptoms or none at all. The virus has power because it is unobservable. SARS, too, was asymptomatic in many people, but not as many as in the case of COVID-19.

When we examine cross-country data, country-specific factors are visible. Within Europe, four countries are prominent: Italy with 69,000 cases, 6800 deaths and more than 3400 in critical care; Spain with 42,000 cases, 2990 deaths, and 2600 in critical care; France with 22,300 cases, 1100 deaths, and 1700 in critical care; and Germany with 33,400 cases, but only 159 deaths and none in critical care.

It is possible that Germany is on an earlier part of the curve and that the contagion in that country had different types of clustering. It is also possible that country-specific factors are in play. For example, demographic factors like the proportion of elderly; environmental factors such as air quality; and social customs relating to how individuals interact.

The most important factor, however, seems to be how we congregate. Population clusters — whether in bars, at football matches, in schools, in apartment complexes, or in households — are what is driving this contagion. Countries with lower population densities, such as Australia and Canada, may be spared the worst. Each currently has relatively few deaths and few in critical care.

Social distancing and quarantining are obvious measures to stop the spread of the virus but we should consider other measures for population clusters such as apartment complexes: perhaps the use of thermometer guns or infrared cameras at their entrances, notwithstanding doubts about the precision of these measuring instruments.

What the data shows is the role of the asymptomatic. It is not only the person sitting next to you who coughs that matters. It is the person who doesn’t cough. That is why it is important to isolate the asymptomatic. The virus depends on the spread from the asymptomatic to the vulnerable.

The segmentation of the asymptomatic from the vulnerable is the key to fighting the virus. It is not sufficient to identify the virus ex-post after the symptoms appear. It must be identified before the symptoms show.

Random testing is the key to stopping this contagion until we can mass-test the entire population.

The lesson is from the town of Vo, where the first death occurred in Italy. All residents of Vo, more than 3000 in all, were tested by the University of Padua. When 89 people tested positive, they were isolated. In the second round of testing, only six were found to be infected and they remained in isolation. Vo has had no more fatalities and a 100 per cent recovery rate. The way to beat the virus is to find it and to isolate it.

The challenge is how to initiate mass testing. That should be the highest priority of governments at all levels. We must isolate the virus, not the people. The only way to do that is to test.

We should begin by testing everyone in nursing homes, in hospitals and everyone at higher risk. But we must also find ways to test those who are not at risk and who are asymptomatic. That means we must begin random testing, not just the testing that follows the identification of an infected person. We must sample the virus in the general population, just as we do with voting.

Random testing is the key to stopping this contagion until we can mass-test the entire population. If a billion dollars were spent on testing and isolating the infected, we may save billions in the months ahead. Testing has to be prioritised. To beat the virus we have to find it and isolate it.

This article was published by The East Asia Forum.  A version of this article was originally published here on The Australian Financial Review.