Quarantine
By Dr.Jerome
Karwacki 12 March 2020
MY take on the current COVID situation
The concept of quarantine began in the 14th
century to control the spread of plague (Black Death). Ships would be made to
wait outside the port, in isolation, for 40 days (hence quarto = four or
forty). This was the maximum incubation period for plague. Unfortunately,
plague is spread, with the assistance of fleas, via rats and was not completely
controlled by attempting to reduce human-to-human transmission.
From a purely technical point of view,
isolation or quarantine, should be more effective in controlling the spread
modern viral respiratory diseases such as SARS, MERS and now COVID. Their
incubation period tends to be closer to 2 weeks than 40 days. But the modern
day concepts of individual freedom and economic pressures tend to play down the
role of imposing a quarantine on the general public.
For purposes of discussion, there are really
three different concepts in play here. As in the original application, one is
the quarantine of an identified group of people who can be isolated until
proven to be disease free. Thailand, for example, repatriated a few hundred
workers from South Korea and placed them in isolation on a military base until
they ‘passed muster’ as disease free. The other, more controversial measure is
a lock-down. Here a population or a geographical area is identified as high
risk and the government takes measures to isolate everyone therein to try to
control the spread of the disease. China and Italy have imposed such widespread
measures in response to COVID.
A third measure aimed to control the
introduction of a disease is to exclude entry from areas that are deemed highly
infected. The USA first did this with travelers from Asia and then Europe to
try to lessen the spread and impact COVID.
In my arrogant opinion (IMHO), actual quarantine of potentially
infected people makes perfect sense and is morally and legally justified. This
assumes that the quarantined person does not suffer a great financial burden;
the government must supply housing and necessities free of change. In the same
vein, self-quarantine should be an individual responsibility. It seems to go
without explaining that here a person who believes he may have come in contact
with the disease isolates himself from the society in general until he is
proven well or must seek medical attention. Many returning travelers need to
consider this mode of action to safe guard the public health. In a pure sense,
self-quarantine is a small scale, self-imposed form of lock-down.
Lock-down and exclusion are more severe forms
of action and must be applied with care and concern. These could be considered
as a mild form of martial law since they would have to be imposed by and
literally policed by gov’t agents. The economy of such an area will be greatly
depressed with wide-spread consequences. Personal freedoms will be severely
impacted and it is unlikely that any gov’t will assume financial responsibility
or recompense. But they should be quite effective in limiting the spread of
respiratory viruses.
Another factor that plays into the decision to
impose any of these measures is termed the R0. It is a mathematical estimate of
the infectiousness of a particular agent. It is a measure of the number of
people that any one case of the disease is expected to infect. With viral
diseases especially, this factor can be corrupted because with such diseases
there are likely to be a fair (to large) percentage of infected people who
never show overt symptoms and are never counted as actual cases but still
infect others The largest R0 (prior to vaccines) was attributed to simple
measles with each case spreading the disease to 12-18 persons. COVID seems to
have an R0 in the range of 4-7. For comparison, other recent flu-like diseases:
SARS had an R0 of 2-5 and MERS <1. Polio, back in the day, was 5-7. Most
viral diseases have an R0 of 5-7 while AIDS stands at 2-5.
It is also a characteristic of viral diseases
that are able to rapidly mutate, hence the shifts that take place in the annual
influenza viruses. Those strains of the virus that are more effective at moving
from person-to-person tend to survive and shift the infectiousness factor
higher. If a virus is too lethal – meaning it kills the host – it tends to die
off itself faster since its infectiousness factor (R0) is likely to be lower.
MERS was recent example.
There doesn’t appear to be any evidence that
the novel corona virus causing COVID has begun to mutate or evolve as yet. Only
time will tell. A stable (non-mutating) virus may allow for a more rapid
development of an effective vaccine. A vaccine that is directed at an early
sample of the virus may not be effective if that virus has already mutated to
another form.
It does appear as though an infected person is
most at risk of spreading the COVID disease while he has overt symptoms:
coughing and sneezing. One reason measles has such a high R0 is that it is shed
by persons who have yet to show any symptoms; neither they nor you know that
they are sick.
One issue with estimating the spread of a
disease is a case definition of that disease: who actually has it and who
doesn’t. All of these recent respiratory diseases start out the same with a
“flu-like” illness. For COVID, a lingering dry cough seems to be a key symptom.
Clinical symptoms are a poor way to diagnose and classify a person as a ‘case’.
Test kits are available that can confirm the coronavirus as the cause.
Unfortunately, access to such testing is proving to be a limiting factor.
General availability to such kits is limited by the number available and their
distribution. Another factor is the cost of running the test. Currently,
testing requires an actual laboratory so that kits may need to be transported
long distances to the proper lab. This delays the confirmation and notification
of a ‘case’. Meanwhile, if the tested person is not under some form of
isolation, the R0 comes into play.
A common fallacy among the general public is
that paper or cloth face masks are an effective way to reduce the spread of
these respiratory viruses. They may be effective but not in the way most people
think. As such things go, the coronavirus is a rather large one, but it is
still small enough to pass through paper or cloth face masks. Fortunately, this
is NOT the way it is transmitted. IOW, it is not floating around in the air for
you to inhale. It is spread by sneezing and coughing but it settles onto
surfaces. It can linger there for 7-10 hours. Any surface that others have
touched is a potential resting place for this virus: door handles, elevator
buttons, grocery carts, etc. You touch them, pick up the virus and transfer it
to your body.
The main utility of using a face mask is to
keep you from touching your own face. Entry points for this virus are your
mouth, nose and eyes. Add glasses (even sunglasses) and you have blocked those
main points of entry. This is the reason why hand washing becomes plays such a
vital role in prevention. Wash your hands as often as possible; especially
before eating and when you return home. Using alcohol-based sanitizers is a
good second level action but soap and water (for at least 20 seconds) are
better at removing the virus.
IMHO, washable cotton gloves would be a more
effective barrier method of preventing one’s exposure to the virus lurking in
the environment. Much like the protective gowns and gloves that medical workers
use as PPE, such gloves would be shed (then washed with hot water and bleach)
upon arrival at home. However, I didn’t see them become part of the modern
fashion trend.
It also appears that the mortality from COVID
is concentrated in the elderly especially if that individual has other
lung-related issues. Common flu targets this population group as well as
infants and children due to their lack of immunity. This is a factor to be
considered in prioritizing how any vaccine will be distributed. Health care
workers (due to higher likelihood of exposure) and the elderly (higher
mortality) would like be the target of the first batches.
A ray of hope? It seems that this virus’ life
span is reduced at temperatures above 30C. Exposure to direct sunlight (the UV
rays) also kills the virus. On the flip side, however, many of the places we go
are air conditioned to below 30C so protection is still needed. If you look at
the countries with the highest number of cases, currently all are in cooler
climates in the midst of their winter season. The Southern Hemisphere, to
include Australia, is in its summer season. It’ll be interesting to see if
transmission changes as the seasons change over the next few months.
I considered chopping this essay into smaller pieces but decided to dump it
on you all at once. I THINK I’ve accurately describes the current (MAR 2020)
understanding of the disease and measures to be taken. Finally, comment /
warning: It is likely to get worse before it gets
better!