QUARANTINE

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!