COVID-19 vs. Seasonal Flu

Clifton Smith

May 3rd, 2020

Other Reports

How an unflattened curve can overwhelm a healthcare system.*

Introduction

Compounding the uncertainty is the fact that crucial early testing in the U.S. was extremely sluggish. Consider that, although the U.S. and South Korea both reported their first cases on the same day (January 20th, 2020), by March 24th, South Korea had tested 348,582 people while the U.S., with a population six times that of South Korea, had only tested 359,000 people.* (More on testing here.)

If we were to grant, hypothetically, that COVID-19 were “merely” as bad as the 2017-2018 flu in the U.S., that would mean the 45 million illnesses, 810,000 hospitalizations, and 61,000 flu deaths would all be more than doubled. I say more than doubled because those figures factor in the use (by ~40% of the U.S. population) of flu vaccines. So, given that a new strain of flu, like COVID-19, would not already have a vaccine, that new strain might easily kill an additional 67,000 people atop the estimated 61,000 that died from flu-related illness during that season, in addition to causing roughly a million more hospitalizations.*



Total Mortality Data

COVID-19 Deaths vs Average of All Deaths — Select Regions

COVID-19 Deaths vs Average of All Deaths — UK; France; Spain; New York City, Netherlands, and Jakarta*

Notes: This information was compiled by New York Times journalists. What should be striking is that they have found an excess of 46,000 deaths over normal weekly averages in several regions they were able to analyze. As of this writing, the Johns Hopkins worldwide tracker of confirmed deaths from COVID-19 stands at 247,497. The additions from NYT represent more than an 18% increase over official numbers from Johns Hopkins*, assuming all excess deaths are COVID-19 related.

A 4/22 article in the Wall Street Journal also highlights the need for more mortality data:

Overall mortality figures are still more exact than tallies of coronavirus cases or deaths and less prone to local variation, say actuaries and epidemiologists. Rates of testing for infection vary widely, even within countries. Many reported deaths from Covid-19, the disease caused by the coronavirus, aren't medically confirmed by postmortem testing.*

On May 2nd, the Washington Post published the results of a joint study with Yale. The team estimated that the actual number of deaths related to COVID-19 between mid-March and early April was roughly 36% higher than previously reported figures.*

Some caveats regarding using total mortality data:

It's not yet clear what effect nationwide shutdowns might be having on other causes of deaths such as traffic fatalities and gun deaths. Recent data from The Trace show a 6% increase in gun deaths between March 1st and April 19th compared to figures for the past three years.* Figures regarding traffic fatalities are mixed, but fewer cars on the road may reduce auto fatalities overall.*

show a 6% increase in gun deaths between March 1st and April 19th compared to figures for the past three years.* Figures regarding traffic fatalities are mixed, but fewer cars on the road may reduce auto fatalities overall.* The USA Today reported April 29th that, between March 22 to April 11, 16,785 more people died than historical averages for the same period. However, they further noted that number is lower than the 23,460 COVID-19 deaths reported during the same time period, in part because 28 states have so far reported fewer deaths than average. That might mean fewer people have died there than is typical, or it might just mean the states haven’t finished reporting deaths to the CDC, a process that can take up to two months.*

U.S. Reported Weekly COVID-19 Deaths vs Deaths by Other Causes

U.S. COVID-19 Deaths vs Heart Disease, Cancer, 2017-18 Flu, Car Accidents*

Notes: This is a slightly abridged version of a chart prepared by writers at The New Atlantis. A caveat here is that flu deaths are estimates based on reported cases. There likely will not be reliable COVID-19 death estimates for at least a year.



U.S. Reported Flu Deaths vs. Reported COVID-19 Deaths

U.S. Reported Flu Deaths 2013–2020 vs. Reported COVID-19 Deaths*

Notes: What we know as annual flu death figures are actually estimates carefully extrapolated from reported flu death figures to adjust for undercounting. COVID-19 death figures are based on counting deaths of people clinically diagnosed as having had the illness. If we compare reported COVID-19 deaths with confirmed flu deaths, we get the above comparison, which is more apples to apples.



COVID-19 Testing

U.S. COVID-19 Total Tests Administered - Trend

COVID-19 Testing in U.S., January 26th through May 3rd*

Worldwide Total COVID-19 Tests Performed per Million

Cumulative tests per million, select countries through April 26th*

U.S. COVID-19 Tests Per Capita

U.S. COVID-19 tests per capita as of May 3rd, 2020*

U.S. COVID-19 Positive Tests to Total Tests Ratio

U.S. COVID-19 Total tests to positive tests ratio as of May 3rd, 2020*

COVID-19 Overview

Age Groups Most Vulnerable to Flu and COVID-19

Case Fatality Rates: U.S. Seasonal Flu vs. COVID-19*

[Enlarge]

COVID-19 Survival on Surfaces

The coronavirus typically spreads via airborne droplets from an infected person's coughs or sneezes. Live coronavirus particles can survive for a time on surfaces.*

COVID-19 R0 - Infectiousness Comparison

Scientists use R0 (“R naught”) to estimate how many people one sick person will likely infect.*

The Flu

U.S. Seasonal Flu Death Estimates

U.S. Estimated Influenza Disease Burden

by Season 2010-11 through 2018-19*

The asterisks by the two most recent seasons in the table are there because the data have not yet been finalized for those.



U.S. Seasonal Flu Peak Months

U.S. Peak Month of Flu Activity 1982-1983 through 2017-2018*

U.S. Seasonal Flu Healthcare Admissions - I

Percentage of visits for influenza-like illness (ILI) U.S. 2013-14 influenza season and selected previous seasons*

I added months and colors to make it easier to discern where in the year the data points are falling.



U.S. Seasonal Flu Healthcare Admissions - II

Percentage of visits for influenza-like illness (ILI) U.S. 2016-17 influenza season and selected previous influenza seasons*

Estimated Flu Deaths by Week - I

Estimated Flu Deaths by Week, 2014-2015 Season*

I was also curious to see how many weeks the seasonal flu typically takes to peak. In this case, it was about 7–8 weeks.

Here again, I've added month labels and colors to make the time of year easier to discern.*



Estimated Flu Deaths by Week - II

Estimated Flu Deaths by Week, 2015-2016 Season*

Further Areas to Explore