VIRUSES

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There is currently a lot of concern about COVID-19. This is being regarded by some as the end of the world, by others as the retribution of God, and by others as the Earth striking back against the creators of global warming…. It is none of these, just a pandemic. Over the course of human history, there have been many pandemics that had a major impact on human populations and history itself.

 In our most recent history, there was and still is the Human Immunodeficiency Virus (HIV) pandemic. When HIV was first described in the mid 1980’s, there was a great outcry that it was the next great pandemic. Experts at the time estimated that it would kill upwards to 20% of the world population in 10 years and a much higher percentage in developing nations. HIV never became as serious as estimated because of dedication to good research, medical science, and excellent education. Today HIV remains a very serious illness, but it is very well understood, and excellent antiviral medications have been developed. As a result, it is under good control, at least in developed nations.

 The last major, true worldwide pandemic was the Spanish Flu Pandemic in 1918.

 From 1918-1919 the Spanish Flu raced around the globe, the worst influenza pandemic to date. Caused by an H1N1 flu virus, it was responsible for more than 500,000 U.S. deaths, as compared to 50,000 US servicemen who died in WWI the previous two years. The worldwide death estimates range from 20 million to 100 million.

 This Spanish Flu pandemic occurred before the invention of antibiotics. Antibiotics are essential in treating the secondary bacterial infections that often kill flu-weakened patients. So, that number would most likely be much lower today with the use of antibiotics to treat the potentially life-threatening secondary respiratory infections and pneumonias.

 MajorWorldwide Pandemics: (only the largest pandemics are noted.)

DATE

CAUSE

DEATHS

165-180

Smallpox

30% of Europe, Asia, and North Africa

541-542

Bubonic plague

40% of the European population

1346-1350

Plague

30%-70% of the European population

1629-1631

Plague

280,000 deaths worldwide

1665-1666

Plague

100,000 deaths in England,(Great Plague)

1816-1826

Cholera

>100,000 deaths in Europe and Asia

1829-1851

Cholera

>100,000 Asia, Europe, and North America

1852-1860

Cholera

1,000,000 deaths in Russia

1875

Measles

40,000 deaths in Fiji

1889-1890

inf luenza

1,000,000 deaths worldwide

1899-1923

Cholera

>800,000 Europe, Asia, Africa

1918-1920

Influenza

75,000,000 deaths worldwide

1957-1958

Influenza

2,000,000 deaths worldwide

1968-1969

Influenza

1,000,000 deaths worldwide

1960 – now

HIV/AIDS

30,000,000 deaths worldwide

2009-2010

Influenza

14,286 deaths

2013-2014

Ebola

6,000+ deaths

Dec 31, 2019 -Now

COVID-19

21,191 deaths as of March 25

 In regard to pandemics, smallpox is no longer a threat, declared eliminated as of 1974 through the efforts of worldwide vaccination programs… I guess they aren’t evil conspiracies, after all.

The plague and cholera are bacterial infections; therefore, they can be treated with antibiotics allowing us to more easily control and prevent them from causing an epidemic today. HIV is still a serious illness, but it is not the threat that it once was as we now have effective antiviral treatments for those infected with this virus.

 The major pandemics and the ones that we are still at risk for today are the viral illnesses. These viral illnesses can be highly contagious and most likely do not have any effective treatment or vaccine to treat or prevent them. In order for a virus to cause a worldwide pandemic, it has to virulent, contagious, easily spread from person to person by airborne (coughing and sneezing), direct contact (body fluid), or indirect contact (on door knobs, etc.). This is why it is so important for everyone to understand and to practice good Body Substance Isolation (BSI) procedures.

 WHAT VIRUSES ARE:

 Let’s take a minute and review exactly what a virus is.

 A virus is a single-celled organism that consists of a protective protein envelope that surrounds genetic material, either DNA or RNA. They do not contain any organelles or other cellular material. They do not feed, excrete waste products, or breed.

 Viruses are intracellular obligate parasites. This means that in order for them to survive and thrive, they are obligated to, or must, gain entrance into and live inside another cell, thus the “intracellular”. They are parasitic because they live in that cell to the detriment of that cell. Therefore, all viruses are intracellular obligate parasites.

 Viruses do not have the ability to reproduce on their own. They attach themselves to the surface of another cell and inject their genetic material into that cell. The virus DNA or RNA then migrates into the nucleus of the host cell where it insinuates itself into the host genes and turns the host cell into a virus factory. That cell then replicates the viral envelope and the viral DNA or RNA. The host cell eventually fills with the newly formed viruses to the point of bursting, thus releasing the virus back into the local area to spread to other cells or into the surrounding t issues. It is this tissue destruction that causes the symptoms.

 Viruses are very tissue-specific.

Viruses cannot simply invade any old cell. They are looking for specific types of cells to invade and infect. For example, the common cold virus only invades respiratory epithelial cells. These cells are in your nose, sinuses, throat, and lungs. Thus the symptoms of a common cold are congestion, sore throat, dry cough, and general malaise, all caused by invasion and destruction of the cells that were infected by the virus.

 Examples are viruses and what tissue they attack and destroy.

  • Chickenpox attacks the skin.

  • Mumps infects the parotid salivary glands.

  • HIV at tacks and destroys the T-lymphocytes of our immune system. These are the cells which are responsible for turning on our immune system.

  • Viruses that cause the common cold attack the respiratory epithelial cells in our sinuses and throat.

  • Influenza attacks the respiratory epithelial cells of the lungs, causing a viral pneumonia.

  • Viruses that cause encephalitis attack the cells of the brain.

  • Viruses that cause meningitis attack the cells of the meningial coverings of the brain and spinal cord.

  • Rabies virus at tacks and destroys nerve cells in the brain.

  • COVID-19 appears to attack respiratory goblet cells and ciliated cells

 There are many viruses that attack the skin and cause rashes, called viral exanthums. As well, there are many viruses that attack the cells that line our intestinal tract causing diarrhea.

 Viruses do not survive well outside the host. Viruses are destroyed by the action of drying out, heat, ultraviolet light, or simple washing with soap and water. But, sneezing, coughing, or dirty hands easily spread viruses from person-to-person.

 Viruses are not sensitive to antibiotics.

Symptoms are based on the particular cells that the virus has invaded and is destroying. The body will typically respond with a low-grade fever (less than 39C). We rely upon our immune system to produce antibodies to destroy the invading virus. There are some antiviral medications that interfere with the virus’s ability to reproduce and are used in potentially life-threatening illnesses such as AIDS.

 Vaccines prepare our immune system f or the invasion.

Today vaccines are used to boost the immune system and manufacture the antibodies directed against life-threatening diseases such as polio, rabies, or smallpox. Once vaccinated, our immune system will make the antibodies to protect us from an infection. If we are subsequently exposed to that virus, the antibody already exists in our bloodstream to destroy it before it can cause any harm.

 Quarantine is the primary treatment for most viral infections.

Unfortunately, with most viral infections the virus is already being released and spread before the major symptoms set in. But once the symptoms appear the individual who is sick needs to quarantine. In other words, they should stay at home, get lots of rest, drink plenty of fluids, giving the body a chance to produce the antibodies and destroy the virus while developing immunity to future infections.

 The problem with quarantining people is twofold.

  • First most people will not stay at home; they feel that they have to go to work or to school which therefore means they give their illness to everyone else.

  • The second problem concerns what happens when the outbreak is on a larger, epidemic or pandemic scale. It can be very difficult, if not impossible, to quarantine a family, a neighborhood, a community, a town, a province, or even a whole country.

 We are a very mobile society. This is the biggest problem today with regard to containing viruses. People were much less mobile in 1918, and that alone did more to control the pandemic than anything else. Today, with all the air travel, automobiles, and mass transit, people are constantly on the move. Containing them and controlling them to minimize or contain a pandemic is extremely difficult and requires a lot of cooperation from the populace.

 

COVID-19

On December 31 of last year, Chinese authorities alerted the World Health Organization of an outbreak of a novel strain of coronavirus causing severe illness, which was subsequently named SARS-CoV-2. As of February 20, 2020, nearly 167,500 COVID-19 cases had been documented, although many more mild cases had likely gone undiagnosed. The virus had killed over 6,600 people.

covid-19.jpg

Shortly after the epidemic began, Chinese scientists sequenced the genome of SARS-CoV-2 and made the data available to researchers worldwide. The resulting genomic sequence data has shown that Chinese authorities rapidly detected the epidemic and that the number of COVID-19 cases had been increasing because of human to human transmission after a single introduction into the human population.

 Common symptoms include fever, cough, and shortness of breath. Muscle pain, sputum production, diarrhea, and sore throat are less common. While the majority of cases result in mild symptoms, some progress to pneumonia and multi-organ failure. As of 25 March 2020, the rate of deaths per number of diagnosed cases is 4.5 percent; however, it ranges from 0.2 percent to 15 percent, according to age group and other health problems. The fatality rate varies widely from place to place and over time, due to variation in how broadly a population is tested and due to variations in availability of sufficient healthcare facilities and personnel.

 The virus is typically spread during close contact and via respiratory droplets produced when people cough or sneeze. Respiratory droplets may be produced during breathing but it is not considered airborne. It may also spread when one touches a contaminated surface and then their face. It is most contagious when people are symptomatic, although spread may be possible before symptoms appear. The virus can live on surfaces up to 72 hours. Time from exposure to onset of symptoms is generally between two and fourteen days, with an average of five days.

 Prevention

 Recommended measures to prevent infection include frequent hand washing, social distancing (maintaining physical distance from others, especially from those with symptoms), covering coughs and sneezes with a tissue or inner elbow, and keeping unwashed hands away from the face. The use of masks is recommended by some national health authorities for those who suspect they have the virus and their caregivers, but not for the general public, although simple cloth masks may be used by those who desire them. There is no vaccine or specific antiviral treatment for COVID-19. Management involves treatment of symptoms, supportive care, isolation, and experimental measures.

 Using a hand sanitizer containing at least 65% alcohol will keep your hands free from viruses. If they are dirty, washing with hot water and soap will provide protection. Just having a virus o your skin is not problematic, but if you touch your face, the virus can find a point of entry through your mouth, nasal passages, or eyes.

 A weak bleach solution makes a good surface cleaner. Add 4 teaspoons of household bleach to 1 liter of cold water, shake, and then use it to disinfect countertops, floors, et cetera. Hot water will not work, as it will cause the bleach to deactivate rapidly.

 The World Health Organization (WHO) declared the 2019–20 coronavirus outbreak a Public Health Emergency of International Concern (PHEIC) on 30 January 2020 and a pandemic on 11 March 2020. Local transmission of the disease has been recorded in many countries across all six WHO regions.

 Those infected with the virus may be asymptomatic or develop flu-like symptoms, including fever, cough, fatigue, and shortness of breath. Emergency symptoms include difficulty breathing, persistent chest pain or pressure, confusion, difficulty walking, and bluish face or lips; immediate medical attention is advised if these symptoms are present. Less commonly, upper respiratory symptoms, such as sneezing, runny nose, or sore throat may be seen. Symptoms such as nausea, vomiting, and diarrhea have been observed in varying percentages. Some cases in China initially presented only with chest tightness and palpitations. Anosmia (loss of the sense of smell) and dysgeusia (distortion of the sense of taste) are reported symptoms, particularly of cases with no other symptoms. In some, the disease may progress to pneumonia, multi-organ failure, and death.

 As is common with infections, there is a delay from when a person is infected with the virus to when they develop symptoms, known as the incubation period. The incubation period for COVID-19 is typically five to six days but may range from two to 14 days. 97.5% of people who develop symptoms will do so within 11.5 days of infection.

 Resources:

 World Health Organization.   https://www.who.int/

 Government of Canada, Health Services.  https://www.canada.ca/en/public-health/services/diseases/coronavirus-disease-covid-19.html

 United States Centers for Disease Control.  https://www.cdc.gov/coronavirus/2019-ncov/index.html