What is COVID-19 (coronavirus disease)?
COVID-19 is a new type of disease that was identified in January 2020 after China alerted the World Health Organization (WHO) on December 31st, 2019 to a cluster of people in Wuhan, Hubei province, experiencing an unusual type of pneumonia. The disease was identified approximately one week later as being caused by a new type of coronavirus, which the World Health Organization has called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The exact beginning of the outbreak of this virus is unclear, but experts estimate it started somewhere between mid-November and December 1st, 2019.
Four subgroups of coronavirus have so far been identified: alpha, beta, gamma, and delta. This new coronavirus, SARS-CoV-2, does not belong to any one of these four subgroups, which is why it is termed novel coronavirus (novel meaning new). Coronaviruses are RNA viruses named for the large spikes on their surface that look like a crown (corona means crown in Latin).
Currently, seven coronaviruses known to infect humans have been identified:
- Alpha coronaviruses 229E and NL63
- Beta coronavirus OC43 and HKU1
- Beta coronavirus MERS-CoV (this causes Middle East Respiratory Syndrome, or MERS, first identified 2012)
- Beta coronavirus SARS-CoV (this causes severe acute respiratory syndrome, or SARS, first identified 2003)
- SARS-CoV-2, the novel coronavirus that causes COVID-19
These viruses originally circulated in animals before evolving to infect humans. Alpha 229E and beta OC43 were discovered in humans in the 1960s but were estimated to have infected bats and cows respectively for hundreds of years. HKU1 and NL63 were only identified after the 2003 SARS outbreak but appeared to have been circulating in humans for many years.
Virus identification has come a long way in the last century, and current detection methods are now sophisticated enough to observe that the initial jump from animals to humans typically triggers widespread disease, as demonstrated by SARS, then MERS and now SARS-CoV-2. Experts suspect the same thing happened with 229E, OC43, HKU1, and NL63 but at the time, sickness caused by these new viruses was just assumed to be caused by one of the many already known viruses.
There are likely many more coronaviruses that have not yet been identified.
Why is COVID-19 (coronavirus disease) so bad?
There are several features about COVID-19 that are concerning, for example:
- COVID-19 is caused by an RNA virus (SARS-CoV-2) and this type of virus replicates quickly and often mutates. Mutates means “to change”, and viruses that mutate have the potential to quickly become resistant to antibodies already produced by an individual’s immune system, antivirals used to treat them, and vaccinations used to prevent them. Currently, scientists have identified two main strains of SARS-CoV-2:
- The L-strain, which is more aggressive and causes 70% of illness
- The S-strain (or group of strains), which makes up the other 30% of cases, which causes more mild disease.
- SARS-CoV-2 is a new virus to which no one has immunity, unlike seasonal flu strains which many people globally have built up immunity to
- Although SARS-CoV-2 is not as contagious as influenza, it is more likely to cause severe disease
- Unlike the most common circulating strains of influenza, there is currently no vaccine against SARS-CoV-2, although one is in the early stages of development.
Experts are still unsure about many aspects of the virus, such as how it spreads, how contagious it is and who is more at risk, although as time goes on more and more of these questions are being answered.
What is the death rate of COVID-19 (coronavirus disease)?
There is some discrepancy over the actual death rate of COVID-19, with different analyses stating it could be as low as 1.4% (Chinese government) to as high as 3.4% (World Health Organization). Seasonal influenza kills approximately 0.1% of those infected every year.
However, there are certain groups of people who are much more at risk of dying if they catch the virus, and so the actual death rate will be higher in these groups.
People more likely to develop severe pneumonia from SARS-CoV-2 include:
- Men (men are approximately 12% more likely to catch the virus and 25 to 40% more likely to die)
- Smokers (smokers have an increased risk of developing pneumonia from the virus)
- Those aged over 65 years (nearly 50% require ICU admission and up to 10% die)
- Those with underlying medical conditions, such as heart disease, lung disease, or diabetes.
How do you catch COVID-19 (coronavirus disease)?
The virus, SARS-CoV-2, that causes COVID-19 is mainly spread from person-to-person, for example:
- If a person infected with SARS-CoV-2 coughs or sneezes within six feet (2 meters) of you and droplets are dispersed into the air that you breathe in or land on you and then you transfer them into your mouth or nose
- If a person infected with SARS-CoV-2 touches you, or you touch a tissue or other object contaminated by their secretions
- If you handle bodily fluids or feces from a person infected with SARS-CoV-2.
Experts also believe the virus can survive on hard surfaces (such as door handles, benches) for up to nine days and can be picked up by touching these surfaces and then touching your face, nose or eyes, transferring the virus.
It appears that people are most contagious (able to spread the virus) when they are at their sickest. However, some spread might be possible before people show symptoms, or in people that are showing very few symptoms.
What are the symptoms of COVID-19 (coronavirus disease)?
Symptoms of COVID-19 resemble those of many other respiratory illnesses, such as the cold or the flu, and also resemble pneumonia.
The main symptoms include:
- Difficulty breathing (this may be a sign of possible pneumonia and you should seek immediate medical attention)
- Severe pneumonia
Not everybody develops severe symptoms, in fact, more than 60% of people have mild or undetectable symptoms.
How long does it take for symptoms of COVID-19 (coronavirus disease) to show?
Experts are not sure exactly how long the incubation period of the SARS-CoV-2 virus lasts for (this is the time it takes from being exposed to the virus to the time it takes for you to show symptoms), but health officials suggest anywhere from two to fourteen days to develop symptoms of COVID-19, if you were to develop them (not everybody infected with the virus develops symptoms).
Am I at risk of catching COVID-19 (coronavirus disease)?
In addition to certain health conditions, other factors that make some people more likely to catch SARS-CoV-2 and develop COVID-19 include:
- Attendance at large gatherings of people, especially in enclosed spaces
- Caring for somebody who already has COVID-19
- Failing to follow basic hygiene measures (such as washing and drying your hands properly before eating, after going to the toilet, and several times throughout the day)
- Having direct contact with infectious secretions from a patient with COVID-19 (such as sputum, serum, blood, or respiratory droplets)
- If you are aged over 65 years (nearly 50% require ICU admission and up to 10% die)
- Traveling by cruise liner
- Traveling to an area known to have community spread of SARS-CoV-2
- Smoking (increases the risk of developing pneumonia from the virus)
- Spending time within close contact (6ft [2 meters]) of a person already infected with SARS-CoV-2
For unknown reasons, men are more susceptible to SARS-CoV-2, being 12% more likely to catch the virus and 25 to 40% more likely to die from COVID-19.
Although travel bans initially slowed the spread of SARS-CoV-2 to most of the world, these were only temporarily effective. This is because it took some time for the virus to be identified and for travel bans to be put in place. As a result, many people who were already infected with the virus were able to return to their home countries or travel abroad, mostly unaware that they were infected with the virus. Experts estimate up to 60% of people with the virus have no symptoms or very mild symptoms that go undetected, so there would have been no reason for them to delay their travel.
This has allowed the virus to “seed” itself (become established) in communities all around the world, for example, South Korea, Iran, and Italy. As a result, the virus has been allowed to spread easily and sustainably throughout these communities (this is called community spread).
Case numbers of people with COVID-19 are increasing daily throughout the United States. Initially, the virus was first reported among close contacts of returned travelers from Wuhan. But since then, community spread has seen cases appear in many states, including Oregon and Washington. Of note was a severe outbreak in a long-term care facility in Washington.
How is COVID-19 (coronavirus disease) diagnosed?
The Centers for Disease Control and Prevention (CDC) have developed a testing kit to help diagnose people who are suspected of being infected with SARS-CoV-2.
If you suspect you may have developed COVID-19, ring your doctor first before presenting to your health care facility. If your doctor asks you to come in, wear a face mask and avoid close contact with other people.
If your symptoms are mild, your doctor may ask you to self-isolate yourself at home. But if your symptoms are severe, you may be admitted to a hospital for treatment.
Do not go to work, travel, or attend family or large gatherings if you have developed COVID-19.
How is COVID-19 (coronavirus disease) treated?
Although there is no specific treatment for COVID-19, the following may reduce symptoms:
- Antivirals approved for other viral illnesses
- Supportive treatment, such as fluid replacement.
How do I protect myself from catching COVID-19 (coronavirus disease)?
Currently, a vaccine is not available to protect against SARS-CoV-2. The best way to protect yourself and others from developing COVID-19 is to:
- Avoid close contact with people who are sick with cold or flu-like symptoms
- Avoid group gatherings
- If you cough or sneeze cover your mouth and nose with a tissue and then throw that tissue in the trash straight away
- Refrain from shaking hands
- Refrain from touching your mouth, nose, and eyes with your hands
- Stay home when you are sick and do not prepare food or attend to others. If you cannot avoid doing this, wear a face mask and wash your hands frequently
- Wash your hands for 20 seconds and then dry them thoroughly before eating, after blowing your nose, going to the toilet, or after touching hard surfaces, and then several more times throughout the day. If hand washing facilities are not available, use a hand sanitizer that contains at least 60% alcohol
- Wipe down hard surfaces (such as door handles, computer keyboards, stairway banisters) frequently
- Get plenty of sleep, be active, and eat healthy, nutritious food. Consider supplements known to boost your immune system
People who have symptoms of COVID-19 should wear a facemask to help prevent the spread of the disease to others. There is no evidence that people who are not sick are less likely to become sick by wearing a face mask, and widespread use of face masks means that supplies are often hard to come by for people who need them most (such as health care workers or caregivers of people who are sick).