Rants, Raves, Reviews & Reflections: March 2020

The virus has been named “SARS-CoV-2” and the disease it causes has been named “coronavirus disease 2019” (abbreviated “COVID-19”).(1)

Illness Symptoms
Reported illnesses have ranged from very mild (including some with no reported symptoms) to severe, including illness resulting in death. While information so far suggests that most COVID-19 illness is mild, a report out of China suggests serious illness occurs in 16% of cases. Older people and people of all ages with severe underlying health conditions — like heart disease, lung disease and diabetes, for example — seem to be at higher risk of developing serious COVID-19 illness.(1)

The WHO reported, as of 20 February 2020 and based on 55924 laboratory confirmed cases, typical signs and symptoms include:

Fever (87.9%)
Dry cough (67.7%)
Fatigue (38.1%)
Sputum production (33.4%)
Shortness of breath (18.6%)
Sore throat (13.9%)
Headache (13.6%)
Myalgia or arthralgia (14.8%)
Chills (11.4%)
Nausea or vomiting (5.0%)
Nasal congestion (4.8%)
Diarrhea (3.7%)
Hemoptysis (0.9%)
Conjunctival congestion (0.8%). (6)

Severity of COVID-19 Symptoms
Among 44,000 confirmed cases in China:
81% Mild Cases
14% Severe Cases
5% Critical Cases (11) (15)

How long does COVID-19 last?

The median length of time from infection of SARS-CoV-2 till you develop symptoms is 5.1 days.(8) This pre-symptomatic period—also known as "incubation"—can range from 1 to 14 days.

The median time from onset of symptoms to clinical recovery for mild cases is approximately 2 weeks and is 3-6 weeks for patients with severe or critical disease.(6)

How many people die from the infection?
I. Case Fatality Rate
Most current discussions of the mortality risk of COVID-19 refer to the case fatality rate (CFR). This is the metric we will focus on, but it is crucial to understand the caveats to this data, and how it differs from alternative measures.

The CFR is calculated by dividing the total number of deaths from a disease by the number of confirmed cases

CFR = Number of deaths from disease/Number of diagnosed cases of disease x 100

The trouble with the CFR is that often many cases of a disease are never diagnosed making the number of confirmed smaller than the number of total cases.

The case fatality rate should not be confused with the crude mortality rate from the disease. The crude mortality rate measures the probability that any individual in the population will die from the disease – not just those who are confirmed cases. It’s calculated by dividing the number of deaths from the disease by the total population.

Measuring and interpreting the case fatality rate

There is no single case fatality rate for a disease – it is context-specific, changing with time and location. The probability that someone dies from a disease is not only dependent on the disease itself, but also the social and individual response to it: the level and timing of treatment they receive, and the ability of the given individual to recover from it.

This means that the CFR can decrease or increase over time, and that it can vary by location and by the characteristics of the infected population (age, sex, pre-existing conditions).(11)

With this in mind, here are some numbers:

3.4% Mortality Rate estimate by the World Health Organization (WHO) as of March 3(10)

6.7% Mortality Rate according to WHO dashboard as of 04/16/20

*Read (16) for more info on how the CFR can be an inaccurate estimate of the death rate

II. Other Estimates
Researchers from the University of Bern in Switzerland released a not yet peer reviewed paper which attempts to account for under reported cases and the time delay to death. Their work resulted in a case fatality rate of 1.6% (17)

III. Age, Sex, Existing Conditions of COVID-19 Cases and Deaths
*All of the following info comes from (13)

There are two sources that provide age, sex, and comorbidity statistics:

The Report of the WHO-China Joint Mission published on Feb. 28 by WHO, which is based on 55,924 laboratory confirmed cases and a paper by the Chinese CCDC released on Feb. 17, which is based on 72,314 confirmed, suspected, and asymptomatic cases of COVID-19 in China as of Feb. 11.

The following list data from both, labeling them as "confirmed cases" and "all cases" respectively in the tables.

A. COVID-19 Fatality Rate by AGE:
*Death Rate = (number of deaths / number of cases) = probability of dying if infected by the virus (%). This probability differs depending on the age group. The percentages shown below do not have to add up to 100%, as they do NOT represent share of deaths by age group. Rather, it represents, for a person in a given age group, the risk of dying if infected with COVID-19.

AGE	DEATH RATE confirmed cases	DEATH RATE all cases
80+ years old	21.9%	14.8%
70-79 years old		8.0%
60-69 years old		3.6%
50-59 years old		1.3%
40-49 years old		0.4%
30-39 years old		0.2%
20-29 years old		0.2%
10-19 years old		0.2%
0-9 years old		no fatalities

B. COVID-19 Fatality Rate by SEX:

SEX	DEATH RATE confirmed cases	DEATH RATE all cases
Male	4.7%	2.8%
Female	2.8%	1.7%

C. COVID-19 Fatality Rate by COMORBIDITY:

PRE-EXISTING CONDITION	DEATH RATE confirmed cases	DEATH RATE all cases
Cardiovascular disease	13.2%	10.5%
Diabetes	9.2%	7.3%
Chronic respiratory disease	8.0%	6.3%
Hypertension	8.4%	6.0%
Cancer	7.6%	5.6%
no pre-existing conditions		0.9%

How does COVID-19 compare to the Flu?
"While many people globally have built up immunity to seasonal flu strains, COVID-19 is a new virus to which no one has immunity. That means more people are susceptible to infection, and some will suffer severe disease."(10)

Globally, about 3.4% of reported COVID-19 cases have died. By comparison, seasonal flu generally kills far fewer than 1% of those infected."

Here's how the death rates of the two compare in different age brackets:(14)

How long can new coronavirus survive on surfaces or in air?

The new coronavirus can live in the air for several hours and on some surfaces for as long as two to three days, tests by U.S. government and other scientists have found.(4)

Will warm weather curb new coronavirus?

It’s too early to know. A few researchers have prepared analyses on the subject, but none have been yet been published in scholarly journals, which require papers to be vetted by experts working in the same field. A group of U.S. and Iranian researchers concluded that the places Covid-19 infection has mostly taken hold so far -- such as Wuhan in central China, Milan and Seattle -- share similarly mild humidity and temperatures ranging from about 5 to 11 degrees Celsius (41 to 52 degrees Fahrenheit) in winter. In hotter, more humid places like Bangkok the virus has mainly been seen in people who brought it in from outside, and has not spread quickly through the community, the researchers said. However, they said predictions should be regarded with “extreme caution.”(5)

Can you be infected with the new coronavirus through food?
Experiences from previous outbreaks of related coronaviruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), show that transmission through food consumption did not occur. At the moment, there is no evidence to suggest that coronavirus is any different in this respect.(9)

Can people who recover from COVID-19 be infected again?

The immune response to COVID-19 is not yet understood. Patients with MERS-CoV infection are unlikely to be re-infected shortly after they recover, but it is not yet known whether similar immune protection will be observed for patients with COVID-19.(7) Though there have been reports of people testing positive a second time after health officials believe these cases are likely the result of testing errors rather than reinfection. (12)

What do the terms isolation, quarantine, social distancing and community containment mean?
These terms all refer to actions intended to stop or slow the spread of a highly contagious disease.

Isolation is the separation of ill persons with contagious diseases from non-infected persons to protect non-infected persons, and usually occurs in hospital settings. (18)

Quarantine refers to the movement restriction of persons who are presumed to have been exposed to a contagious disease but are not ill, either because they did not become infected or because they are still in the incubation period. Quarantine may be applied at the individual or group level and usually involves restriction to the home or a designated facility. Quarantine may be voluntary or mandatory.(18)

Social distancing refers to actions to reduce interactions between people in a broader community, in which individuals may be infectious but have not yet been identified hence not yet isolated. As diseases transmitted by respiratory droplets require a certain proximity of people, social distancing of persons will reduce transmission. Examples for social distancing include closure of schools or office buildings and suspension of public markets, and cancellation of gatherings. (18)

Community containment refers to interventions applied to an entire community, city or region, designed to reduce personal interactions and movements. Such interventions range from social distancing among (such as cancellation of public gatherings, school closures; working from home) to community-use of face masks to locking down entire cities or areas. (18)

What does it mean to "flatten the curve"?
Measures such as social distancing are used to slow the rate of infection in an attempt to avoid overwhelming healthcare facilities. This is often explained using a graph with two curves. The first represents the increase of infected people if no action is taken. The second "flattened curve", shows the results of slowing the spread of the disease.

Image Source University of California San Francisco

How long will social distancing measures need to be in effect?
"To avoid a rebound in transmission, these policies will need to be maintained until large stocks of vaccine are available to immunise the population—which could be 18 months or more,"(19)

"a policy of alternating between periods of more and less strict social distancing measures could plausibly be effective at keeping the number of critical care cases within capacity. These would need to be in place for at least most of a year. Under such as policy, at least half of the year would be spent under the stricter social distancing measures."(20)

Covid Act Now provides state by state modeling. I have not assessed the accuracy of this data or their modeling methods.

Here is their graph for Kentucky:

Is Lockdown the best way to deal with coronavirus?
Sweden
Unlike most countries, Sweden didn’t go into lockdown or impose strict social-distancing policies. Instead, it rolled out voluntary, ‘trust-based’ measures: it advised older people to avoid social contact and recommended that people work from home, wash their hands regularly and avoid non-essential travel. But borders and schools for under-16s remain open — as do many businesses, including restaurants and bars.(22)

Sweden's case fatality rate as of 04/23/20 is 12.06% which is higher than neighboring Denmark (4.88%), Finland (4.01%) and Norway (2.59%).(23) But as widely reported in the early part of the pandemic, the goal of flattening the curve was to keep healthcare facilities from being overrun. "Sweden's strategy would have been considered a failure if it had resulted in a peak of cases so high that the health care system had become overwhelmed and people who could have otherwise been saved died from lack of care. We are nowhere close to the end of this, but the models and pundits that predicted this outcome happening as early as late March were wrong. The Swedes who have died from the coronavirus did not die due to lack of hospital beds or ventilators."(24)

What are the strategies for dealing with coronavirus?

Look into:
https://thecitizen.com/2020/06/13/june-13-pandemic-report-cases-up-but-hospital-icu-admissions-down/

https://www.cebm.net/covid-19/covid-19-declining-admissions-to-intensive-care-units/

(1) CDC: Coronavirus Disease 2019 (COVID-19) Situation Summary

(2) CDC: Coronavirus Disease 2019 (COVID-19): Symptoms

(3) CDC: Coronavirus Disease 2019 (COVID-19): How COVID-19 Spreads

(4) Time: Novel Coronavirus Can Live on Some Surfaces for Up to 3 Days, New Tests Show