Corona Virus Disease of 2019 (COVID-19): People Who Are At Risk Of Developing Severe COVID-19

What is COVID-19?

COVID-19 means Corona Virus Disease of 2019, is a pandemic disease (disease that spread from one country to and affects large number of people) that affects the respiratory tract characterized by cough, shortness of breath, runny nose and cause many complications if left untreated.

The name "Corona Virus" is derived from Latin Corona meaning crawn or wreath, itself a borrowing from Greek word kopwvn korone.

According to Emedicine, Coronavirus disease 2019 (COVID-19) is defined as illness caused by a novel coronavirus now called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; formerly called 2019-nCoV), which was first identified amid an outbreak of respiratory illness cases in Wuhan City, Hubei Province, China. It was initially reported to the WHO on December 31, 2019. On January 30, 2020, the WHO declared the COVID-19 outbreak a global health emergency. On March 11, 2020, the WHO declared COVID-19 a global pandemic, its first such designation since declaring H1N1 influenza a pandemic in 2009.

Illness caused by SARS-CoV-2 was termed COVID-19 by the WHO, the acronym derived from "coronavirus disease 2019." The name was chosen to avoid stigmatizing the virus's origins in terms of populations, geography, or animal associations. 

On February 11, 2020, the Coronavirus Study Group of the International Committee on Taxonomy of Viruses issued a statement announcing an official designation for the novel virus: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

The Centers for Disease Control and Prevention (CDC) has estimated that SARS-CoV-2 entered the United States in late January or early February, establishing low-level community spread before being noticed. Since that time, the United States has experienced widespread infections, with nearly 23 million reported cases and over 383,000 deaths reported as of January 14, 2021.

On April 3, 2020, the CDC issued a recommendation that the general public, even those without symptoms, should begin wearing face coverings in public settings where social-distancing measures are difficult to maintain in order to abate the spread of COVID-19.

The CDC had postulated that this situation could result in large numbers of patients requiring medical care concurrently, resulting in overloaded public health and healthcare systems and, potentially, elevated rates of hospitalizations and deaths. The CDC advised that nonpharmaceutical interventions (NPIs) will serve as the most important response strategy in attempting to delay viral spread and to reduce disease impact. Unfortunately, these concerns have been proven accurate. 

 COVID-19 Route of Transmission

The principal mode by which people are infected with SARS-CoV-2 is through exposure to respiratory droplets carrying infectious virus (generally within a space of 6 feet). Additional methods includes contact transmission (eg, shaking hands) and airborne transmission of droplets that linger in the air over long distances (usually greater than 6 feet).

Virus released in respiratory secretions (eg, during coughing, sneezing, talking) can infect other individuals via contact with mucous membranes.

On July 9, 2020, the World Health Organization issued an update stating that airborne transmission may play a role in the spread of COVID-19, particularly involving “super spreader” events in confined spaces such as bars, although they stressed a lack of such evidence in medical settings. Thus, they emphasized the importance of social distancing and masks in prevention.

The virus can also persist on surfaces to varying durations and degrees of infectivity, although this is not believed to be the main route of transmission.

One study found that SARS-CoV-2 remained detectable for up to 72 hours on some surfaces despite decreasing infectivity over time. Notably, the study reported that no viable SARS-CoV-2 was measured after 4 hours on copper or after 24 hours on cardboard.

Oran and Topol estimate asymptomatic persons account for approximately 40-45% of SARS-CoV-2 infection. These asymptomatic carriers can transmit infection to others for an extended period, perhaps more than 14 days, and therefore, contribute to substantial spread of the disease.

Utilizing a decision analytical model, Johansson et al from the US Centers for Disease Control and Prevention assess transmission from presymptomatic, never symptomatic, and symptomatic individuals across various scenarios to determine the infectious period of transmitting SARS-CoV-2. They estimate at least 50% of new SARSCoV-2 infections originated from exposure to individuals with infection, but without symptoms.

Transmission of SARS-CoV-2 from 12 young children who acquired COVID-19 at childcare facilities to family members has been reported. Findings showed 25% of their close contacts became infected, most often mothers or siblings. 

In a separate study, Chin and colleagues found that the virus was very susceptible to high heat (70°C). At room temperature and moderate (65%) humidity, no infectious virus could be recovered from printing and tissue papers after a 3-hour incubation period or from wood and cloth by day two. On treated smooth surfaces, infectious virus became undetectable from glass by day 4 and from stainless steel and plastic by day 7. “Strikingly, a detectable level of infectious virus could still be present on the outer layer of a surgical mask on day 7 (~0.1% of the original inoculum).” Contact with fomites is thought to be less significant than person-to-person spread as a means of transmission.

Wölfel and colleagues reported that, in a small group of patients with mild COVID-19, nasopharyngeal/oropharyngeal swabs collected during the first week of illness showed infectious virus but not after this period despite high detected rates of SARS-CoV-2 RNA from these sites.

How Viral shedded?

The duration of viral shedding varies significantly and may depend on severity. Among 137 survivors of COVID-19, viral shedding based on testing of oropharyngeal samples ranged from 8-37 days, with a median of 20 days.

A different study found that repeated viral RNA tests using nasopharyngeal swabs were negative in 90% of cases among 21 patients with mild illness, whereas results were positive for longer durations in patients with severe COVID-19. In an evaluation of patients recovering from severe COVID-19, Zhou and colleagues found a median shedding duration of 31 days (range, 18-48 days). These studies have all used PCR detection as a proxy for viral shedding. The Korean CDC, investigating a cohort of patients who had prolonged PCR positivity, determined that infectious virus was not present.

Additionally, patients with profound immunosuppression (eg, following hematopoietic stem-cell transplantation, receiving cellular therapies) may shed viable SARS-CoV-2 for at least 2 months.

In a 2020 study on the efficacy of facemasks in preventing acute respiratory infection, surgical masks worn by patients with such infections (rhinovirus, influenza, seasonal coronavirus [although not SARS-CoV-2 specifically]) were found to reduce the detection of viral RNA in exhaled breaths and coughs. Specifically, surgical facemasks were found to significantly decreased detection of coronavirus RNA in aerosols and influenza virus RNA in respiratory droplets. The detection of coronavirus RNA in respiratory droplets also trended downward. Based on this study, the authors concluded that surgical facemasks could prevent the transmission of human coronaviruses and influenza when worn by symptomatic persons and that this may have implications in controlling the spread of COVID-19.

In a 2016 systematic review and meta-analysis, Smith and colleagues [50] found that N95 respirators did not confer a significant advantage over surgical masks in protecting healthcare workers from transmissible acute respiratory infections.

Bae and colleagues, in a letter to Annals of Internal Medicine, reported that surgical and cotton masks were ineffective at containing cough droplets of SARS CoV-2 in a study conducted in two hospitals in Seoul, South Korea. Although the study methods were somewhat questionable in terms of mimicking natural transmission (the patients were asked to cough on culture plates placed 20 cm from their mouths), the results may indicate the value of maintaining social distancing even while a mask is worn.

SARS-CoV-2 has also been found in the semen of men with acute infection, as well as in some male patients who have recovered.

Asymptomatic/presymptomatic SARS-CoV-2 infection and its role in transmission.

Data suggest that asymptomatic patients are still able to transmit infection.This raises concerns for the effectiveness of isolation.

Oran and Topol published a narrative review of multiple studies on asymptomatic SARS-CoV-2 infection. Such studies and news articles reported rates of asymptomatic infection in several worldwide cohorts, including resident populations from Iceland and Italy, passengers and crew aboard the cruise ship Diamond Princess, homeless persons in Boston and Los Angeles, obstetric patients in New York City, and crew aboard the USS Theodore Roosevelt and Charles de Gaulle aircraft carrier, among several others. They found that approximately 40-45% of SARS-CoV-2 infections were asymptomatic. 

Epidemiology

Coronavirus outbreak and pandemic.

As of January 14, 2021, confirmed COVID-19 infections number over 90 million individuals worldwide and has resulted in over 1.9 million deaths. More than 220 countries have reported laboratory-confirmed cases of COVID-19 on all continents except Antarctica.

In the United States, nearly 23 million reported cases of COVID-19 have been confirmed as of January 14, 2021, resulting in over 383,000 deaths, making it the third leading cause of death after heart disease and cancer. Beginning in late March 2020, the United States had more confirmed infections than any other country in the world. The United States also has the most confirmed deaths in the world, followed by Brazil and India.

CDC estimates of COVID-19 epidemiology parameters.

In late May 2020, the CDC and the Office of the Assistant Secretary for Preparedness and Response (ASPR) released parameter values intended to support public health preparedness and planning for the COVID-19 pandemic. Their “best estimates” for viral transmissibility, disease severity, and presymptomatic and asymptomatic disease transmission of COVID-19 based on current data are as follows:

Basic reproduction number (R 0 or R-naught): 2.5

Asymptomatic SARS-CoV-2 infection rate: 40%

Infectiousness of asymptomatic individuals relative to symptomatic individuals: 75%

Percentage of transmission occurring prior to symptom onset: 50%

Time from exposure to symptom onset: Mean of 6 days 

Time from symptom onset in an individual and symptom onset of a second person infected by that individual: Mean of 6 days

Ratio of estimated infections to reported case counts: Mean of 11 

Infection fatality ratio (IFR)

IFR is the number of individuals who die of the disease among all infected individuals (symptomatic and asymptomatic)

19 years or younger: 0.00003

20-49 years: 0.002

40-69 years: 0.005

70 years or older: 0.054

  Classification of Corona Virus

Realm: Rivovira

Kingdom: Orthonavirae

Pylum: Pisuviricota

Class: Pisoniviricetes

Order: Nidovirales

Family: Coronaviridae

Sub family: Orthocoronavirinae

What are the types of Corona Virus?

Doctors currently recognize seven types of corona virus that can infect human being. Among them four common type are:

NL63 (alpha corona)

229E (alpha corona)

OC43 (beta corona)

HKU 1 (beta corona)

What are the symptoms of COVID-19?

The most common symptoms of COVID-19 are:

Cough

Shortness of breath

Fever, chills

Sore throat

Runny nose

Muscle pain

Fatigue

Headache

Loss of appetite

Loss of smell

Nausea and vomiting.

  Causes of COVID-19

Infection with the new coronavirus (severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2) causes coronavirus disease 2019 (COVID-19).

The virus that causes COVID-19 spreads easily among people, and more continues to be discovered over time about how it spreads. Data has shown that it spreads mainly from person to person among those in close contact (within about 6 feet, or 2 meters). The virus spreads by respiratory droplets released when someone with the virus coughs, sneezes, breathes, sings or talks. These droplets can be inhaled or land in the mouth, nose or eyes of a person nearby.

In some situations, the COVID-19 virus can spread by a person being exposed to small droplets or aerosols that stay in the air for several minutes or hours — called airborne transmission. It's not yet known how common it is for the virus to spread this way.

It can also spread if a person touches a surface or object with the virus on it and then touches his or her mouth, nose or eyes, although this isn't considered to be a main way it spreads.

Some reinfections of the virus that causes COVID-19 have happened, but these have been uncommon.

  Risk factors for COVID-19

Risk factors for COVID-19 appear to include:

Close contact (within 6 feet, or 2 meters) with someone who has COVID-19

Being coughed or sneezed on by an infected person

If you have a pre-existing condition/Non communicable disease, you may be infected with Corona virus and be at risk of becoming severely ill. These conditions include:

Diabetes

Chronic respiratory disease

Cancer

Cardiovascular disease (heart and blood vessels disease).

Hypertension

Heart attack

Medical advice for people affected by these conditions to stay safe:

1. Keep distance from sick people

2. Secure one month+ supply of medication

3. Protect mental health

4. Stop drinking alcohol and smoking

5. Wash your hands frequently

6. Take your medicine and follow medical advice.

How are coronaviruses diagnosed?

COVID-19 can be diagnosed similarly to other conditions caused by viral infections: using a blood, saliva, or tissue sample.

However, most tests use a cotton swab to retrieve a sample from the inside of your nostrils.

Locations that conduct tests include:

the CDC

some state health departments

commercial companies

certain pharmacies

clinics

emergency rooms

community testing centers.

Visit the websites of your state’s health department or the U.S. Department of Health & Human Services to find out where testing is offered near you.

At-home tests

On November 17, 2020, the Food and Drug Administration (FDA) issued its first emergency use authorization (EUA) for a COVID-19 self-testing kit.

The EUA specifies that the test kit is authorized for use by people ages 14 years and older whom healthcare professionals have identified as having suspected COVID-19.

The Lucira COVID-19 All-In-One Test Kit is a rapid test, which means that the nasal swab sample doesn’t have to be sent off to a lab. The test kit is available by prescription only and promises results within 30 minutes.

Back on April 21, 2020, the FDA authorized the use of the first COVID-19 home collection kit. It’s produced by Pixel by LabCorp.

A cotton swab is provided, and people will be able to collect a nasal sample with it and mail it to a designated laboratory for testing.

It’s authorized for use by people ages 18 years and older.

When to see your doctor

Talk with your doctor right away if you think you have COVID-19 or you notice symptoms.

Your doctor will advise you on whether you should:

stay home and monitor your symptoms

set up a telehealth visit

come into the doctor’s office to be evaluated

go to the hospital for more urgent care

turn to experts who understand and can help strengthen your mental well-being.

  Complications of COVID-19

Although most people with COVID-19 have mild to moderate symptoms, the disease can cause severe medical complications and lead to death in some people. Older adults or people with existing chronic medical conditions are at greater risk of becoming seriously ill with COVID-19.

Complications can include:

Pneumonia and trouble breathing

Heart problems

Organs failure

A severe lung condition that causes a low amount of oxygen to go through your bloodstream to your organs (acute respiratory distress syndrome)

Blood clots

Acute kidney injury

Additional viral and bacterial infections.

What treatments are available?

There’s currently no cure for an infection with the new coronavirus. However, many treatments and vaccines are currently under study.

On October 22, 2020, the FDA approved its first COVID-19 treatment, the medication remdesivir (Veklury). It’s available by prescription for people ages 12 years and older who’ve been hospitalized. It’s administered as an intravenous (IV) infusion.

In November 2020, the FDA also granted EUAs to monoclonal antibody medications. Monoclonal antibodies are human-made proteins that help to fight off foreign-made substances, such as viruses.

These medications are:

bamlanivimab, from Eli LillyTrusted Source

casirivimab and imdevimab, which must be administered together, from Regeneron PharmaceuticalsTrusted Source

Like remdesivir, they’re also administered by IV infusion and intended for people ages 12 years and older. These medications are used for outpatient therapy.

The FDA has also issued EUAs to a few other treatments, such as convalescent plasma, that are intended for people who are hospitalized or at high risk for hospitalization.

Most COVID-19 treatment focuses on managing symptoms as the virus runs its course.

Seek medical help if you think you have COVID-19. Your doctor will recommend treatment for any symptoms or complications that develop and let you know if you need to seek emergency treatment.

Treatments for other coronaviruses

Other coronaviruses such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) are also treated by managing symptoms. In some cases, experimental treatments have been tested to see how effective they are.

Examples of therapies used for these illnesses include:

antiviral or retroviral medications

breathing support, such as mechanical ventilation

steroids to help reduce lung swelling and inflammation

blood plasma transfusions

How can you prevent COVID-19?

The best way to prevent the transmission of the virus is to avoid or limit contact with people who are showing symptoms of COVID-19 or any respiratory infection.

The next best thing you can do is practice good hygiene and physical distancing to prevent bacteria and viruses from being transmitted.

  Prevention tips for COVID-19

Wash your hands frequently for at least 20 seconds at a time with warm water and soap. How long is 20 seconds? About as long as it takes to sing your “ABCs.”

Don’t touch your face, eyes, nose, or mouth when your hands are dirty.

Don’t go out if you’re feeling sick or have any cold or flu symptoms.

Stay at least 6 feet (2 meters) away from people. Avoid crowds and large gatherings.

Cover your mouth with a tissue or the inside of your elbow whenever you sneeze or cough. Throw away any tissues you use right away.

Clean any objects you touch a lot. Use disinfectants on objects like phones, computers, and doorknobs. Use soap and water for objects that you cook or eat with, like utensils and dishware.

Multiple vaccines are in development, and they’ll soon be available to the public and used for prevention. Some have already proven to be effective in clinical trials.

On December 11, 2020, the FDA granted its first EUA for a vaccine. This vaccine was developed by Pfizer and BioNTech. It can be given to people ages 16 years and older.

On December 18, the FDA granted an EUA to a vaccine developed by Moderna. The Moderna vaccine can be given to people ages 18 years and older.

Should you wear a mask?

If you’re out in a public setting where it’s difficult to follow physical distancing guidelines, the CDC recommends that you wear a cloth face mask or covering that covers your mouth and nose.

When worn correctly, and by large percentages of the public, these masks can help to slow the transmission of SARS-CoV-2.

That’s because they can block the respiratory droplets of people who may be asymptomatic or people who have the virus but have gone undiagnosed.

You can make your own mask using basic materials such as:

a bandana

a T-shirt

cotton fabric.

The CDC provides instructions for making a mask with scissors or with a sewing machine.

Cloth masks are preferred for the general public since other types of masks should be reserved for healthcare workers.

It’s critical to keep the mask or covering clean. Wash it after each time you use it. Avoid touching the front of it with your hands. Also, try to avoid touching your mouth, nose, and eyes when you remove it.

This prevent you possibly for transferring the virus from a mask to your hands and from your hands to your face.

Keep in mind that wearing a face mask or covering isn’t a replacement for other preventive measures, such as frequent handwashing and practicing physical distancing. All of them are important.

Certain people shouldn’t wear face masks, including:

children under 2 years old

people who have trouble breathing

people who are unable to remove their own masks.

Sources:

www.emedicine.medscape.com

www.who.int

www.healthline.com

www.mayoclinic.org