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COVID-19 - Facts, Myths, knowns & unknowns

We are in a most uncertain time of our lives, where the globe has become standstill. It’s almost like a war situation where the enemy is invisible and no firing, no bombing and no peace treaty. A similar yet much dreadful 1918 Spanish flu (H1N1) pandemic has infected 500m people, one third of world population at that time and killed 50m people affecting USA, Europe, Africa and some parts of Asia including India.

This time around we are dealing with rapidly travelling SARS-CoV-2 via international flights cruise ships which affects almost every community in the world. As scientists work round the clock to learn about the virus, the treatment and vaccination to prevent the virus infection, we have known some facts about the virus. I have outlined the known facts about SARS-CoV-2 which I hope will be helpful.

INTRODUCTION TO VIRUSES

Viruses are organisms that live inside the host cells, and they infect any living organisms and multiply within the cells. They are basically parasites and cannot live independently outside the living cells for long periods. Most of the viruses cause acute respiratory infections, mainly upper respiratory tract (Nose, throat, and vocal cord) and sometimes lower respiratory tract (Bronchus, bronchioles or lung parenchyma). They may affect the heart surface (Pericarditis) or muscle (Myocarditis) as well.

Viruses have their own genetic make-up and they tend to infect same species (either human or any animal or bird). However, some virus predominantly affects either animal or bird may infect humans when they get in contact with them. This is called zoonosis. However these viruses do not spread from human to human. Sometimes viruses which affect animals may infect human the first time, then they get adapted to the human host cells and spread from human to human, which is called spill-over effect. This can lead to epidemic or even pandemic.

Viruses constantly change their genetic make-up in order to survive and further propagation. For example, influenza virus slightly change its genetic make-up every year (antigenic drift). Occasionally it makes major change in its genetic make-up (antigenic shift) which becomes more virulent and spread fast, causing pandemic. E.g. Spanish flu in 1919.

Mode of transmission for every virus is different. Generally, they spread from human to human through respiratory secretions. Depends on their mode of transport the method of prevention of such infection also vary. Two common mode of transmissions are airborne (aerosols) or droplets form. Airborne transmission is via small particles from the breath floats around the air, whereas the droplets are large particles, so they are carried with cough, sneeze and nasal secretions and they fall on the ground or surfaces within 1-1.5m distance due to their weight affected by gravity.
 
The method of prevention of the viruses depends on their mode of transmission. Airborne transmission is harder to control, in the sense they float in the air for at least ... minutes after a person who exhaled in the environment. However, droplets do not stay in the air, but they stay on the floor and surfaces for varying length of time depending on the type of virus, type of the surface and the environmental temperature and humidity. The principle of transmission control is therefore is droplet prevention (Cough etiquette, hands sanitization, surface cleaning, Personal protection equipment such as surgical mask, P95 mask, gown, gloves and eye shied / goggles) or aerosol prevention.

EPIDEMIC AND PANDEMIC

Epidemic is an active spread of a disease with new cases exceed what is expected, in a localized area, where as pandemic is the spread of the disease that travel far and wide through the borders to become out of control. Pandemic spread depends on virulence of the virus and ease of travel (rapid people mobilization via aircraft and cruise ships).

WHAT IS COVID-19

COVID-19 (COrona VIrus Disease – 2019) is an infection caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome -Corona Virus 2) virus, which belongs to the family Corona virus.

Other viruses from Corona family generally cause common cold. Disease caused by SARS-1 virus appeared in November 2002 in the Guangdong province of southern China. According to the World Health Organization (WHO), a total of 8,098 people worldwide became sick with SARS during the 2003 outbreak in 26 countries and remained epidemic. Of these, 774 died. Since 2004, there have not been any known cases of SARS reported anywhere in the world.

EFFECTS OF COVID-19

COVID-19 predominantly affects middle-aged to elderly people and severe effect is seen in people with reduced immunity. E.g. People with chronic diseases such as diabetes, severe asthma, chronic obstructive pulmonary disease, heart disease and patients who has active cancer or on immunosuppressive drugs (E.g. Chemotherapy) and elderly people.
COVID-19 generally causes respiratory tract infection and 40% of the affected people have mild symptoms such as sore throat, cough, runny nose, headache and fever. Patient affected by COVID-19 may have systemic (generalised) symptoms such as nausea, vomiting, diarrhoea and body aches and pains. Sometimes the virus multiplies and travel down the air way (Trachea, bronchus and alveoli) to cause pneumonia and severe acute respiratory syndrome. Another 40% of people have moderate symptoms and they may or may not require hospitalization. About 15% of the patients are affected by either pneumonia or severe acute respiratory syndrome and require oxygen therapy. Only 5% become critically ill who require mechanical ventilator. There is emerging information that COVID-19 may affect heart, kidneys and other organs. 

Any information about the unprecedented effect on economies across the world is beyond the scope of this booklet. However, on the health front it has and will continue to impact psychosocial and even physical health of many people for many years to come.

Psychological effect of COVID-19
 
The global outbreak of COVD-19 has impacted psychological health of many people in varying degrees. The knowns, unknowns, fear about uncertainty, loss of income, the lockdown, separation from other family members and fear of contracting the infection are a few common issues people worry and stress about. The level of anxiety varies from person to person-  Many people have mild anxiety and some people develop severe anxiety, causing panic attacks, phobia in certain situations, depression and insomnia. The psychological effects may lead to psychosocial issues such as family problems, alcoholism, substance abuse, domestic violence etc.
 
I recommend some of the simple things that everyone may follow:
 
1. Limit your exposure to news and media to reliable news only
2. Maintain your routines as much as possible
➢ Regular physical activity
➢ Maintain healthy eating
➢ Stay connected with your family and friends via phone or social media
3. Be kind and generous to others If you get an opportunity, assist others who are in need of assistance.
4. Be creative if possible
5. Share your feelings with other family members and children
 
TESTING OF CORONAVIRUS

Several tests have been developed since the outbreak of SARS-CoV-2 in December 2019. Two main methodology are PCR (Polymerase Chain Reaction) and Serology test. PCR test from nasopharyngeal swab (Swab from nose +/- throat) is the main test widely used, in which the antigen (viral RNA) is tested, whereas serology (from blood) detects the immune response of the host, antibodies. PCR test detects people who are currently infected and serology test will detect if a person has been infected and developed immunity to the virus. This is important, as historically patients who were infected by SARS of 2003, had antibodies in their blood years after the infection. It is still not known how the immune response will be, for SARS-CoV-2 infection.

There are reported cases that people have been infected twice by the virus. Nevertheless, at some stage population-based serological testing may help to determine the proportion of people who have immunity to SARS-CoV-2 which will help the authorities to relax the social distancing restrictions. Moreover, this information will provide if the population develops “Herd immunity” i.e. High level of immunity in the population which will stop the virus circulating in the community. This is how the natural flattening of epidemiological graph occurs.

PUBLIC HEALTH MEASURES WHICH PREVENT SPREAD OF COVID-19

Public health Prevention measures of pandemic spread of COVID-19 may be designed in different levels and methods depends on the local situation.
1. Travel warnings and restrictions
Travel warnings start from Level 1 (Practice usual precaution), Level 2 (Practice enhanced precautions) and Level 3 (Avoid non-essential travel) when there is widespread transmission. 
In addition to the travel warnings the government may impose post-travel mandatory quarantine and prohibition of non-citizens from entry. In unprecedented escalation of transmission in the community mainly from international or interstate travel, the borders may be closed.
2. Community containment strategies
Surveillance is the main activity in any country in controlling the disease transmission. This includes case finding (Prompt detection of infected cases) and contact tracing (Detection of contacts who were exposed to persons who are infected). When maximizing early detection of cases, it is important that the testing suspected cases based on symptoms, sites or areas of high risk of infection, and local transmission status.
Isolation refers to the separation of ill persons with COVID-19 infection and quarantine is the separation or restriction of activities of persons who are believed to have been exposed to the infection. This may be either self-home isolation (Voluntary) or mandatory isolation in dedicated facilities. In Australia mandatory quarantine came into effect for inbound passengers.

Social distancing is another important aspect of public measure in controlling human tohuman transmission. These interventions range from measures to increase social distance among community members (e.g., cancellation of public gatherings, use of masks, implementation of community-wide “snow days”) to community-wide quarantine. At the community level this may be implemented to entire community or region, with focus measures such as restriction of non-essential travel/ visit whilst keeping essential services and certain shops open, whilst practicing social distancing all the time.
Sometimes the government imposes widespread community quarantine including cordon sanitaire (Sanitary barrier) with curfews.

Generally, Graded Implementation of Community Containment Measures are necessary in different levels based on ground situation.
 

 
WHAT CAN YOU DO TO PREVENT SPREAD OF COVID-19?

Transmission of any organisms from person to person via respiratory secretions (From nose & throat). Mode of transmission is important to understand to use the appropriate preventive measures.
1. Aerosol transmission
In normal breathing or talking a person generate respiratory aerosols as they are small size particles suspend in the air for a longer period. Some organisms such as tuberculosis (TB), measles and chickenpox transmit via aerosols.

2. Droplet / Contact transmission
Droplets are larger particles (Generally size > 5-10 µm and produced by normal breathing, coughing or sneezing. While normal breathing the droplets travel up to 2m (Distance of social distancing distance). However, coughing and sneezing may propel droplets up to 6m (That’s why cough etiquette is important) As they are larger particles and heavy they fall on the surface / floor. Any direct contact with the nasal / oral secretions may also spread the organisms in the persons hands and may be contaminated in other body areas or objects. Therefore, virus may be found in the surfaces, objects, floor, clothes and even body surfaces from generated droplets or touching contaminated areas (Indirect contact)
 
SARS CoV-2 transmits from person to person either direct or indirect contact as the virus is found in the respiratory secretions (Mucus from nose & mouth) and predominantly transmitted via droplets. There may be some viruses found in aerosols, however a very tiny amount of virus may also spread through aerosols, but the viral concentration is generally not adequate to produce clinical infection. However, aerosol transmission is likely particularly healthcare workers work close proximity in relatively enclosed space for extended period of time (Creates high viral concentration). For this reason, healthcare workers treating patients with symptoms suggesting of COVID-19 or confirmed cases, wear medical mask. There is some evidence the virus may go through the stomach and spread through faeco-oral route as well.

Wearing masks
        In public setting, the main precaution of SARS-CoV-2 transmission is based on droplets and contact preventions. As droplets generally travel up to 2m, social distancing is the most important preventive measure. General public is unlikely contract the virus airborne unless they are unable to avoid crowds and many symptomatic people. Surgical mask is designed to protect droplets (Larger particles) and not aerosols. Therefore, it is not recommended for general public to use surgical mask unless they have any respiratory symptoms, in this situation the mask can prevent him/her spreading the virus to others.

In healthcare setting, the healthcare workers generally use surgical masks (one mask per patient) when they encounter a patient with respiratory symptoms. However, if a healthcare provider works in a highly contaminated area or treating patients with COVID-19, they should wear N-95 respirator to protect aerosol transmission.

Wearing gloves
       Generally wearing gloves in public settings not necessary as they do not prevent transmission. Regular hand sanitation is more effective. Gloves may carry germs and in fact enhance viral transmission unless you change gloves all the time. In healthcare setting, gloves can prevent transmission when healthcare provider get in contact with the patients with symptoms. The gloves are changed for every patient contact. 


Hand hygiene
  • Wash your hands often with soap and water for at least 20 seconds especially after you have been in a public place, or after blowing your nose, coughing, or sneezing, going to the bathroom; and before eating or preparing food.
  • If soap and water are not readily available, use a hand sanitizer that contains at least 60% alcohol. Cover all surfaces of your hands and rub them together until they feel dry.
  • Avoid touching your eyes, nose, and mouth with unwashed hands. o Avoid close contact with people who are sick 
Respiratory etiquette
  • Cover your mouth and nose with a tissue when you cough or sneeze or use the inside of your elbow.
  • Throw used tissues in the trash.
Environmental cleaning

➢ Do not share: You should not share dishes, drinking glasses, cups, eating utensils, towels, or bedding with other people or pets in your home.

Cleaning around house – What do you need to know?

(1) High risk Situation

  • Household member with COVID-19 positive or
  • Household member is in social isolation (Direct contact with positive case or suspect case waiting for COVID-19 test results)

(2) Moderate risk situation

  • Household member healthcare worker / returning home after visiting high risk areas e.g visiting medical facility
  • Household member is vulnerable E.g. Elderly > 70 years, People with chronic disease such as diabetes or who is on immunosuppressive treatment. 

(3) Low risk situation

  • People who are house-bound who does not have visitors coming into the house and no vulnerable members in the house 



Usual everyday cleaning (Mechanical cleaning)
Use a detergent such as everyday cleaning product (E.g. Spray and wipe) or soap and water to clean high-touched areas.

Cleaning & Disinfecting
First clean the surface with a detergent or soap and water or usual household detergent (E.g Spray & wipe) to remove the dirt, which will make the virus easier to remove. Following this use a disinfectant to kill the virus. Only necessary if a surface has been contaminated with infectious material. The choice of cleaning product will be based on the type of surface you are cleaning and how likely it is that it is contaminated by the COVID-19 virus. If you feel the risk of contamination is high, you may like to opt for a stronger bleachbased solution for the disinfecting part of the process. Wipes can be used to clean surfaces, however, unless the product is a disinfectant that kills viruses, you may need to use a disinfectant product after you clean.
 

Tips for effective cleaning against coronavirus

  • Wear gloves.
  • Use a clean cloth or disposable paper towel.
  • Cleaning: Pay special attention to the bathroom and toilet, as well as frequently touched surfaces such as tables, countertops, light switches, doorknobs and cabinet handles, and personal items such as mobile phones.
  • Disinfecting: Be sure to follow the instructions on products or they could be ineffective. Be careful not to mix different cleaning products, as this can create dangerous solutions. For the disinfectant to be as effective as possible, make sure it has contact with the surface for at least 5–10 minutes to kill bacteria and viruses.
  • Dispose of gloves and cleaning cloth (or wash thoroughly) and wash your hands thoroughly with soap and water.
  • You do not need to be obsessive in frequent cleaning and disinfecting if you are not in high risk situation. Once a day through cleaning of high-touched surfaces are suffix.
  • And airdry for at least 10 minutes 

➢ Disinfecting clothes
Disinfect laundry basket with disinfectant as outlined above. Use laundry detergent with contains bleach (If appropriate to the clotehs) Choose warmest available water setting (Usually 60 -90°C) (SARS CoV-2 is sensitive to heat at 70°C)

➢ Disinfecting shoes
This may only be necessary for those who work in high risk environment/ highly infected area.
Remove your shoes & socks in the garage or entrance or keep them in plastic bags The shoes may be disinfected with a disinfectant wipe.
 

Masks to symptomatic individuals

  • If you are sick: You should wear a facemask when you are around other people (e.g., sharing a room or vehicle) and before you enter a healthcare provider’s office. If you are not able to wear a facemask (for example, because it causes trouble breathing), then you should do your best to cover your coughs and sneezes, and people who are caring for you should wear a facemask if they enter your room.
  • If you are NOT sick: You do not need to wear a facemask unless you are caring for someone who is sick (and they are not able to wear a facemask). Facemasks may be in short supply and they should be saved for caregivers.

 

Monitor symptoms of healthy individuals

  • Seek medical care and call ahead to your Doctor if you have symptoms of a fever, cough, shortness of breath, pain or pressure in your chest, confusion, bluish lips or face 

Isolation & treatment of infected

If you are sick with COVID-19 or suspect you are infected with the virus that causes COVID-19, follow the steps below to help prevent the disease from spreading to your co-workers, family or others:

  • Stay at home until instructed to leave: Patients with confirmed COVID-19 should remain under home isolation precautions until the risk of secondary transmission to others is thought to be low.
  • Talk to your healthcare provider: The decision to discontinue home isolation precautions should be made on a case-by-case basis, in consultation with healthcare providers and state and local health departments.
  • Stay away from others: As much as possible, you should stay in a specific room and away from other people in your home. Also, you should use a separate bathroom, if available.
  • Limit contact with pets & animals: You should restrict contact with pets and other animals while you are sick with COVID-19, just like you would around other people. Although there have not been reports of pets or other animals becoming sick with COVID-19, it is still recommended that people sick with COVID-19 limit contact with animals until more information is known about the virus.
  • When possible, have another member of your household care for your animals while you are sick. If you are sick with COVID-19, avoid contact with your pet, including petting, snuggling, being kissed or licked, and sharing food. If you must care for your pet or be around animals while you are sick, wash your hands before and after you interact with pets and wear a facemask. 
Myths & Facts about Wearing facial masks & gloves
     Surgical masks are loose fitting, single-use items that cover the nose and mouth. They are used as part of standard precautions to keep splashes or sprays from reaching the mouth and nose of the person wearing them. They also provide some protection from respiratory secretions and are worn when caring for patients on droplet precautions.

Surgical masks can be placed on coughing patients to limit potential dissemination of infectious respiratory secretions from the patient to others

Author:
Dr S Thava Seelan
MBBS (Syd), FRACGP, DCH
Master of Public Health & Tropical Medicine (JCU)
Director, Bridgeview Medical Practice, Toongabbie, NSW
Conjoint Senior Lecturer, Western Sydney University