The Positivity Rate - Covid19 - GTEC Blog

Rosco Reports IV

by Ross Thrasher

Today’s international coronavirus totals: 2.4 million cases and 165,000 deaths.  The USA represents nearly one-third of these cases and almost one-quarter of the fatalities.

A recent article in The Atlantic discusses a new statistic, the “positivity rate”(PR), the number of positive COVID-19 cases as a percentage of persons tested.  For example, the overall PR in the USA at present is 20%, and some states (NY, NJ) are twice that high.  But only about 1.2% of the country’s population has been tested.  Canada by comparison has a PR of 6% and a test rate of 3%.  This may be a useful metric to employ in the decision about when to relax restrictions in a particular community.  It certainly reinforces the argument that more testing is needed in order to be confident that the virus is receding.  The Atlantic article is worth reading; see below.

Elsewhere, it appears that Russia will be the next epicenter of the COVID-19 pandemic.  The mayor of Moscow ordered everyone indoors on March 30, perhaps a few weeks too late as Russia’s virus cases have been on a steep climb since then, topping 6000 today.  The death rate is still (suspiciously) low, but sure to rise abruptly in the coming weeks.  To their credit the Russians have tested almost two million people already.

Brazil is right behind Russia in total confirmed cases, up to 2500-3000 new ones per day.  But these numbers may be artificially low as Brazil has done very little testing to date.  And the case fatality rate is already a troublesome 6%, around 200 deaths a day for the past week.

Other Latin American countries are starting to experience a sudden bump in new cases, e.g. Mexico, Chile, Ecuador.  And their current positivity rates are all higher than 10%.

Turkey looks like another incipient hot spot, with the new-case numbers rising steadily since late March, into the 4000-5000 range for the past ten days.  Daily deaths are still on the up-slope, in the range of 125 lately.

Until now the coronavirus does not appear to have made major inroads into Africa or South Asia, two regions with large economically-challenged populations.  However, most of these countries have reported very low testing numbers so far.  And the crowded, unsanitary conditions of their large cities could trigger major outbreaks