Data from Iceland suggest that roughly 89 to 94% of infections have gone undetected: BioRxiv

Coronavirus by Engin Akyurt via pixabay.com (open access)

A study published in BioRxiv on April 6 analyzes the reports from Iceland, where a community-wide voluntary random sampling program is underway.  These studies are based on two sample sets, as the abstract explains:

The criteria for testing within the Icelandic medical system, processed by the National University Hospital of Iceland (NUHI), have also been targeted at high-risk individuals, but additionally most Icelanders qualify for voluntary testing through the biopharmaceutical company deCODE genetics.

Based on these samples, the authors of the BioRxiv study analyzed the data and found that:

Our primary estimates for the fraction of infections that are undetected range from 88.7% to 93.6%.

This report reinforces my impression that we are massively underestimating the rate of SARS-COV-2 spread through the community.  My own personal experience suggests that a wave of infections passed through our rural area in mid- to late-February, hitting medical staff at a community clinic through exposure to symptomatic patients before anyone realized what was happening.  Now the infection is reaching shut-ins and chronically ill people who are relatively isolated from the rest of the community.  These patients are the most susceptible to severe and overwhelming disease, and they will represent the largest percentage of deaths due to COVID.

Patients with one foot in the grave will shuffle off the mortal coil and jump into their coffins when they are confronted with SARS-COV-2.  I couldn’t resist using those stereotyped metaphors and similes to make a point: the most delicate patients will suffer the most from this virus.  Robust patients with inapparent disease have spread the virus throughout the community; only 6 to 11% of them have been detected.  Now the isolated patients will begin to fall ill, and they will be detected with much greater frequency.  More than 10% of them will die.