A Deeper Dive Into Public Health Guidelines

Grant Samara COVID-19 Apr 09, 2020

The Invisible Enemy

The COVID-19 pandemic is without a doubt one of the most disruptive global events in recent memory. Although it poses little danger to the average member of the population, its ability to proliferate and infect large numbers of people means that we could see hundreds of millions dead over the next few years. For context, at its worst, Ebola killed 11,000 over the same time span. Because this virus’s primary weapon is how difficult it is to contain, understanding the processes which allow it to spread is vital.

The first such process brings us to the natural history of the illness. The natural history of an illness is the typical behavior of the disease in a person over a period of time. The following is the natural history of COVID-19:

Graph by Grant Samara

In this chart, the incubation period is the time at the early stage after a person has been infected, during which the person can transmit the pathogen to other people, but has not yet developed symptoms. During the incubation period, the infected person and those in contact with the person are unaware of the infection and cannot take precautions against the spread of the infection. COVID-19 has an incubation period of around 5 days, meaning that a person who begins to show symptoms has already been infecting other people for about 5 days.

Another factor which enables COVID-19 to spread so easily is its novelty. A population encountering a new virus has little immunity, providing a great number of potential hosts; a population that has encountered a virus will have developed some immunity to the virus. The portion of the population which is immune to the virus provides a kind of barrier in the chain of transmission called herd immunity, preventing the disease from spreading as rapidly. The presence of herd immunity to a virus prevents the virus from infecting a larger portion of the population and spreads the infection over a longer period of time. COVID-19, as a novel virus, has spread rapidly and without opposition, allowing it to infect a significant proportion of the population before any herd immunity could emerge.

In order to counteract the coronavirus’ advantages of a high infection rate, extended incubation period, and immunologic novelty, a set of procedures which can appropriately address each threat is needed. Instead of waiting for symptoms to arise before quarantining, mass social distancing can prevent transmission almost entirely. Because we have no herd immunity, we must find other parts of the chain of transmission to block off, such as wiping down surfaces and washing hands.

Flattening the Curve

One of the silver linings on this virus is the reasonably low mortality. A mortality of 1% is far lower than that of a disease such as smallpox, which has a mortality of 30%. If the mortality were to go up to 20%, then we can expect 20 times as many people would die. One of the reasons that the mortality is not excessively high is that we have treatments for the symptoms of this disease in our hospitals. While this serves to slow down the direct causes of death, we do not yet have a cure for the disease itself.

Ensuring access to hospital care is critical to survival of patients. It is currently estimated that 20% of all cases require hospitalization. Although not all of these cases would die without this care, the majority of them would. Without hospitals, we face the terrifying prospect of mortality that could reach 20%. Take a look at your immediate family and closest friends. With a mortality rate that high, the odds are that at least one of them will die. It could end up being you. To prevent a heightened mortality rate, we must ensure that hospitals are not overrun and remain able to handle the vast influx of patients.

To go about tackling this issue, we must increase hospital capacity and make sure that the number of patients remains small. (To assist in the former, please see LINK.) The latter involves something known as flattening the curve. Flattening the curve is a process in which we spread out the cases over a longer period of time. This has two effects: the peak number of cases is smaller, and it gives time for herd immunity to take effect and bring down the total number of cases. If the peak number of cases remains low enough, the hospital system will have a much easier time in ensuring that everybody who needs treatment gets treatment.

Social Distancing

The easiest ways to slow the spread of the virus is through social distancing. Social distancing is when the entire population no longer goes out in public, no longer engages in human interaction, and in short, does not participate in person-to-person contact. Remember, the primary mode of transmission for COVID-19 is person-to-person, so removing contact will prevent it from spreading. At its best, social distancing would completely kill COVID-19 within two weeks as the virus would find no new hosts to infect. This would not, however, be possible, as there will always be those who ignore the rules, and this small group can harbor the illness for much longer than we could stay inside. Many people also need to get food, receive mail, or go to work for the more essential jobs. The realistic outcome, therefore, is something like this:

Graph by Grant Samara

Notice how much lower the peak is with social distancing. The peak is proportional to the highest load that our hospitals will bear, and if that load exceeds our medical capabilities, the excess people would receive no treatment and likely die. Social distancing can happen between individuals, households, nations, and everything in between. The less in-person interaction that takes place, the less transmission occurs.

Isolation and Contact Tracing

Similar to social distancing, isolation occurs when individuals with a high probability of carrying the virus go into a more thorough quarantine. This means not leaving their homes, avoiding contact with family members or housemates, and having necessities such as food delivered. Isolation was used to great effect in South Korea, bringing their 909 cases per day down to the single digits.

Unfortunately, in order for isolation to work properly, one must know who has the virus. Testing is hard to come by in the US, and since not everyone can be tested, we rely on contact tracing to determine those at risk. Contact tracing is the process wherein every person who has come into contact with a confirmed case within the incubation period is considered infected, and treated as such. This allows us, with a small number of tests, to put most infected persons into isolation.

In places such as the U.S., however, the population is so large and the tests so few that actual epidemiologists cannot perform contact tracing. Instead, each individual must be on the lookout for others becoming ill. If you hear about a person whom you were in contact with recently contracting this virus, go into isolation. If you yourself become infected, do your best to alert those who have contacted you. There is no shame in having this virus, so long as you behave responsibly with it.


An important concept in controlling infection is the prevention of transmission via surface contact. One of the common ways in which a virus spreads is through contact with contaminated surfaces, such as hands, doorknobs, or dirty dishes. These surfaces can be contaminated directly by a host through a number of modes, such as sneezing, touching, or by contacting another contaminated surface. To mitigate this threat, a person must both avoid becoming contaminated by the dirty surfaces and contaminating them for others. There are several ways to do this, and employing them all can keep you free of infection.

While avoiding contact with contaminated surfaces may seem like a good plan,, it’s often difficult to tell what surfaces are contaminated and which ones are clean. Instead, try to minimize the number of things which you touch, particularly in public. If you must touch surfaces in public, be sure to wash your hands. Any hand sanitizer will kill this virus, but for the best results use one with roughly 60% alcohol content. Hydrogen peroxide can also kill this virus. Do not use antibiotics. Antibiotics will not kill this virus(and may assist in the breeding of “superbugs,” or bacteria which cannot be treated medically).

It is not always possible to avoid touching surfaces, and cleaning them can make it more safe to do so. Regularly wipe down exposed surfaces such as car steering wheels and door handles which are touched often. Again, anything which kills the virus on your hands kills it on inanimate objects. By wiping these surfaces, you reduce the number of contaminated surfaces for you to touch.

Finally, wash your hands regularly. Washing your hands both removes the risk of you becoming infected, and the risk of you infecting others. However well you were washing your hands before this pandemic, you must now wash them more. Think of the extra time which you have off work as time for handwashing. Use soap, and if your hands become dry, chapstick or lotion can be used.

Take a Hike

You may feel cooped up over the course of this quarantine. If you must go outside, do not go to a public space. Take a walk around the block, go to a park, or ride a bike. Do not hang out at the mall, go shopping, or meet up with friends. Doing so increases your chances of spreading the virus.

One of the most effective means of sanitation is with Ultraviolet radiation. UV rays are constantly generated by the sun, meaning that with enough time being in sunlight can kill this virus. When you go outside, so long as you stay far away from other people and don’t touch surfaces, you should be fine. Unfortunately, UV rays do not penetrate glass windows, so even in the natural lighting of a skylight COVID-19 can survive.

On top of providing great benefits to your mental health, walks outside can help to prevent infection. So long as you do not expose yourself to the virus, walking outside can help boost your immune system. This has been the cause of many government policies, such as an earlier fishing season to get people outside. As long as social distancing is followed, walking outside can help fight the Coronavirus.

The Animals

When taking your long walks in nature, be conscientious towards animal life in the area. As it turns out, this SARS-COV 19 can infect a wide range of animals which can then transmit the virus to a person. Although there is little information about this interspecies transmission it is still best to avoid all contact with mammals. Most viruses cannot infect such a large variety of species, and the ability to do so has potentially very harmful consequences.

For one, all pets must be treated like people with respect to this virus. This means regular cleaning and social distancing for these animals. If you need to walk your dog, be sure that it does not approach strangers too closely. Do not allow your cat free reign of the outdoors. Doing so risks the lives of both you, your pets, and the strangers in the area.

Besides this, the biggest risk from animals comes from the wild population. These animals can become what is known as a reservoir, or a population which can harbor an infectious disease. If humans infect the wild population, we have no way of removing the virus. We cannot simply ask the raccoons to socialy distance. Instead, the animal population will repeatedly reinfect the human population even after we have mostly eradicated this virus. The virus would become endemic, meaning that it would never be eradicated and continue to kill people until a vaccine is produced, which is not guaranteed.

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