Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus.
Most people infected with the virus will experience mild to moderate respiratory illness and recover without requiring special treatment. However, some will become seriously ill and require medical attention. Older people and those with underlying medical conditions like cardiovascular disease, diabetes, chronic respiratory disease, or cancer are more likely to develop serious illness. Anyone can get sick with COVID-19 and become seriously ill or die at any age.
Meanwhile, People with COVID-19 have had a wide range of symptoms reported – ranging from mild symptoms to severe illness. Symptoms may appear 2-14 days after exposure to the virus. Anyone can have mild to severe symptoms.
Possible symptoms include:
■ Fever or chills
■ Cough
■ Shortness of breath or difficulty breathing
■ Fatigue
■ Muscle or body aches
■ Headache
■ New loss of taste or smell
■ Sore throat
■ Congestion or runny nose
■ Nausea or vomiting
■ Diarrhea
Please Note: People who are older have a higher risk of serious illness from COVID-19, and the risk increases with age. People who have existing medical conditions also may have a higher risk of serious illness. Certain medical conditions that may increase the risk of serious illness from COVID-19 include:
■ Serious heart diseases, such as heart failure, coronary artery disease or cardiomyopathy
■ Cancer
■ Chronic obstructive pulmonary disease (COPD)
■ Type 1 or type 2 diabetes
■ Overweight, obesity or severe obesity
■ High blood pressure
■ Smoking
■ Chronic kidney disease
■ Sickle cell disease or thalassemia
■ Weakened immune system from solid organ transplants or bone marrow transplants
■ Pregnancy
■ Asthma
■ Chronic lung diseases such as cystic fibrosis or pulmonary hypertension
■ Liver disease
■ Dementia
■ Down syndrome
■ Weakened immune system from bone marrow transplant, HIV or some medications
■ Brain and nervous system conditions, such as strokes
■ Substance use disorders
This list is not complete. Other medical conditions may increase your risk of serious illness from COVID-19.
When to Seek Emergency Medical Attention
Look for emergency warning signs* for COVID 19:
■ Trouble breathing
■ Persistent pain or pressure in the chest
■ New confusion
■ Inability to wake or stay awake
■ Pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone
If someone is showing any of these signs, call 911 or call ahead to your local emergency facility. Notify the operator that you are seeking care for someone who has or may have COVID-19.
Causes
The virus causing COVID-19 is officially known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It belongs to a larger family of viruses called coronavirus. Although coronaviruses can affect both animals and humans, only human coronaviruses are known to cause respiratory infections.
There are many genetic variations of the COVID-19 virus called variants. Variants can affect the spread of the virus, how serious an infection is and the protection that you receive from a previous infection, vaccines or treatments. Some variants of concern in Canada include Delta (B.1.617.2) and Omicron (B.1.1.529).
COVID-19 can spread directly from person to person through respiratory droplets. You can also come into contact with the virus through aerosols (droplets small enough to float in the air) created when an infected person coughs or sneezes. These aerosols linger in the air for long periods of time. You may also pick up the virus from touching infected surfaces and then touching your eyes, nose, or mouth.
People with highest risk of exposure include:
■ Individuals who regularly interact with people who are not fully vaccinated
■ Those who care for individuals who have or may have COVID-19
■ People who work in environments with exposure to many individuals
■ Individuals working in group settings such as correctional facilities, long-term care facilities and shelters or group residences
■ Those facing social, economic or personal barriers that limit their ability to implement public health measures.
Making the Diagnosis
If you feel you are experiencing symptoms of a COVID-19 infection you should self-isolate as directed by your local public health authority. Coronavirus infections can be detected by several types of testing methods, including molecular testing, antigen testing and antibody testing. Testing can be done by taking a nasal swab, a throat swab, an oral fluid swab or a saliva sample.
Treatment and Prevention
Most people with mild illness will recover without treatment. However, your health care provider may recommend some available medications to help provide comfort and alleviate symptoms of COVID-19.
Many medications to treat COVID-19 are currently being developed and tested. Health Canada has approved several treatments for COVID-19, including remdesivir and bamlanivimab. Some treatments, such as nirmatrelvir and ritonavir, can be taken orally at home. The availability and eligibility criteria for COVID-19 treatments may vary between across provinces and territories.
Currently, there are several COVID-19 vaccines authorized for use in Canada, including the Pfizer-BioNTech Comirnaty® COVID-19 vaccine and the Moderna Spikevax® COVID-19 vaccine. There are other vaccines currently under review, and Health Canada continues to closely monitor the vaccines that have been approved.
It’s recommended to get fully vaccinated against COVID-19 to lower your risk of getting infected as well as to lower your risk of other outcomes from severe infection such as hospitalization. Your local public health authority may recommend additional COVID-19 vaccine doses (i.e. booster doses) to provide better protection and to reduce the spread of the virus.
Since COVID-19 can spread from person to person, practising good hand hygiene is one of the most important things you can do to keep yourself from being infected. Wear a face mask whenever possible, especially when you’re out in public settings. Avoid touching your eyes, nose, and mouth with unclean hands. You should try to minimize your chances of being exposed to the virus by avoiding contact with people who are sick. If you are sick, you should cover your nose and mouth when sneezing and coughing.
