COVID-19 is a respiratory coronavirus, one that enters the body by infecting tissues in the nose and mouth. From there, it replicates and often moves down the throat and respiratory tree into the lungs, just as many cold and flu viruses do.
In the worst cases, the lung infection provokes a tissue response that produces congestion, inability to breathe, high fever, lung scarring, and damage to the heart and kidneys. Although it is not clear if the virus gets into the brain, many recovered patients experience confusion and poor coordination. In other words, the infection can produce neurological symptoms either directly or because of the tissue inflammation.
Prior to Memorial Day, Franklin County had only two reported cases of COVID-19, but 108 cases had been reported by the end of July. By Monday of this week, cases had surged to 476, because 308 new cases were found in the Franklin Correctional Institution in addition to 165 elsewhere. That means that at least 1 percent of the residents in Franklin County have been infected, and the true number may be as high as 5 percent. We have entered a period in which new infections are being spread through the community.
Until today, only six people have been hospitalized and three have died. As is true elsewhere, these most serious cases affected older citizens, but one must be cautious because the epidemic has only been spreading here for a month. As the figure shows, people of any age can contract the virus, and long-term consequences are only now becoming known.
During a pandemic, there is no such thing as having zero risk; the question is how to limit the chance of infection within one’s own family. Unfortunately, once one family member contracts COVID-19, it is very likely that others will contract the disease, so prevention is truly a family affair. The purpose of this article is to discuss options that may reduce the rate of spread, and to explain more about how the virus damages our organs.
Why face masks work
Face coverings reduce the transmission of COVID-19 and other viruses by about half for a simple reason: Most viruses travel through the air as part of droplets that are large enough to be filtered (see figure 1). To be specific, viruses themselves are about 0.1 micron in diameter, where a micron is one-thousandth of a millimeter. The droplets produced when a person speaks or sings range from 20 to 300 microns, which are trapped by surgical masks and even cloth masks. Most water droplets of this size fall to the ground within six feet, which is why health authorities recommend staying that far from others when in public.
However, the danger of infection increases when a sick person coughs or sneezes because the force of the cough produces much smaller particles called aerosols that cannot be filtered effectively by face masks. Also, coughing is one symptom of infection, so it is advisable to avoid people who cough or sneeze. Aerosols spread on air currents much farther than droplets, and remain in the air far beyond six feet.
It is true face masks are most effective in preventing people who already have the virus from spreading it to others, but masks also cut your chances of breathing particles into your nose where the viruses can begin to replicate and spread to your tissues.
Time, distance and location
When droplets carrying the virus spread into air currents, the “dose” of virus bystanders breathe in depends on how close they are to the infected person, how much time they breathe contaminated air, and whether the virus is confined in a room or may dissipate out of doors.
A handy way to think about distancing is to notice how far you can smell perfume or cigarette smoke, two particles similar in size to viruses. Sitting on a bench outside an auto repair shop last week, I noticed that even with a face mask, I could smell perfume at least 10 feet away and cigarette smoke at about 20 feet. The nerves in the nose that detect these odors are in exactly the same place where COVID-19 binds and begins an infection.
Viruses can also live on surfaces like doorknobs and spread to the next person who opens the door and then touches their eyes, nose or mouth before washing or using hand sanitizer. This risk can be reduced by using a paper towel to open doors or pump gas, for example.
Cost of treatment
About one in 20 people who test positive for COVID-19 develop symptoms that require hospitalization. If symptoms are severe, they may receive treatment with an antiviral such as intravenous Remdesivir, or an anti-inflammatory such as dexamethasone. Hospitalized patients usually experience fever and lung congestion that require care by a respiratory therapist. With an average stay of nine days, costs often range from $24,000 to $34,000, and direct costs to the patient depend on their insurance and co-pay.
About one in five patients hospitalized for COVID-19 requires treatment in an intensive care unit, most often because they require artificial ventilation. Patients requiring ventilator support typically spend about three weeks in hospital, with costs ranging from $88,000 to $250,000.
Up to now, all viral diseases have been contained by being restricted to one season, like flu and the common cold, or by immunity acquired by exposure and development of effective vaccines. It was possible to contain Ebola because people who are ill enough to spread the virus show specific symptoms. Unfortunately, that is not the case for COVID-19 because people can pass on the virus despite feeling no obvious symptoms.
People who develop models to study epidemics say diseases will die away whenever each sick person, on average, infects less than one other person, but will grow if the average patient infects more than one other person. That rate of transmission is called the reproduction number, or R0. For instance, as Germany and South Korea suppressed spread of the virus, R0 fell to 0.8, meaning it was subsiding. However, in July, the value increased to over 2 in the United States, meaning that it was spreading rapidly.
When you hear public health experts like Dr. Anthony Fauci talking about health policies that would end an epidemic, their major question is what actions would reduce the transmissibility to less than 1. And the answers are now almost clichés: Wear face masks in public, wash your hands often, and keep at least six feet away from other people. It seems likely that this virus will spread until more than half the people in each state have become immune either by having had the disease, or from a vaccine. To make a football analogy, we are nearing the end of the first quarter; there are three more to go.
Entering your body
Coronaviruses cause respiratory diseases because they bind strongly to a specific protein called ACE2 that is abundant in the tissues that line our noses, mouths, respiratory tree and lungs. The problem with COVID-19 is not that it does this any better than other coronaviruses, rather that it spreads for several days when there are no symptoms to warn the carrier or contacts of the illness. That is the reason health authorities insist travelers self-quarantine for two weeks.
Viruses are not alive in one sense, namely, they have no metabolism or means of reproducing by themselves. They cannot be “killed” in the common sense, but they become harmless when treated with soap, alcohol, bleaching agents, or ultraviolet light. That is the reason for using hand sanitizers with at least 60 percent alcohol and frequently washing ones hands.
A storm in the body
As COVID-19 replicates in the respiratory tree, newly made viruses are shed into the trachea and bronchial tubes, and gradually pass into the lungs where they bind to cells that line the tiny air sacs. The infection recruits cells from the immune system that begin to attack the infected cells. Unfortunately, the process causes lung blood vessels to become leaky, and fluid builds up and makes it very difficult to breathe. Lung obstruction causes heavily labored breathing and makes the heart work very hard, one of the worst outcomes of the infection.
Because the blood capillaries become leaky, the virus also enters the cardiovascular system, where it circulates and binds to cells in blood vessels, the heart and kidneys doing damage in the process. Unfortunately, when the immune system is activated so much, it produces chemical agents that affect the brain and entire body. In the brain, the inflammatory agents cause fever, chills and sweating. To counteract these symptoms, patients are told to drink fluids and take Tylenol or acetaminophen.
The most serious outcome is called a “cytokine storm,” after the chemical agents coming from the immune system. In the hospital, steroidal agents called dexamethasone and prednisone are given to reduce the severity of the immune response. The problem is not that an immune response occurs, rather, that it is out of control.
From pandemic to endemic
The World Health Organization declared COVID-19 to be a pandemic on March 11, meaning that it has spread to most countries around the world. Cases have been reported in every country in the world.
Originally, it was hoped the disease could be extinguished, rather than becoming well established akin to seasonal flu and the common cold. Given the continuing spread of disease, especially in “hot spots” like Florida and Texas, most experts now think the disease is established, or endemic, and is not going to go away. Like “our love” in the popular song, it is here to stay. Most likely, COVID-19 will continue to spread until the majority of people have survived it and have developed immunity, or have acquired immunity through vaccination.
Adapting to the pandemic
Local hospitals have limited capacity to deal with COVID-19 patients. The preference is to provide home care, but isolating cases from family members as much as possible. Although Weems Memorial Hospital has 25 acute-care beds, only a few are set up for isolation, and there are no intensive care beds. At the end of July, Tallahassee Memorial Hospital had 40 cases of COVID-19. Although there are 72 ICU beds in Tallahassee, they are already near capacity due to treating patients with other conditions.
Epidemiologists, who study the spread of diseases, think in terms of how to reduce the likelihood of contracting diseases. If a disease cannot be stopped, at least one wants to slow the rate of hospitalization because ICU availability limits the ability to care for seriously ill patients.
At present, about 1 percent of people in Franklin County have been exposed. In general, the chance that each person we are exposed to is spreading the disease is about 1 percent, so risk is very manageable if it is possible to remain isolated. But if we go into public buildings, the risk jumps because all the people in the building have been exposed to other family members.
Keeping trips short is one way to reduce risk but that is not possible for classroom teachers, store clerks, and office workers who remain in enclosed spaces for entire workdays. To reopen, it is always best to reduce the spread of disease first, and only then to reopen with precautions. Yes, that is a gloomy outlook given the increasing number of people in Franklin County who have the virus.
Almost the only good news this week was a report that about half of people may already have some immunity to COVID-19 as a result of having been exposed to similar coronaviruses in the past. The immunity did not come from having antibodies; rather it was found that immune cells could defend against the virus despite lack of prior exposure. If that finding applies to Florida, it should be possible to contain the virus by 2020. In the meantime, it is important to limit spread of the virus as much as possible for the rest of this year.
This article originally appeared on The Apalachicola Times: A look at COVID-19 in Franklin County
No comments on this item Please log in to comment by clicking here