Public Health Agency of Canada
CORONAVIRUS HOTLINE 1-833-784-4397
Coronaviruses are a large family of viruses that may cause a range of illnesses in humans, from the common cold to SARS. Viruses of this family also cause a number of animal diseases.
Pandemic Coronavirus (COVID-19)
On December 31, 2019 the WHO China Country Office was informed of cases of pneumonia of unknown etiology detected in Wuhan City, Hubei Province of China. The outbreak began in a seafood and poultry market in Wuhan, a city of 11 million in central China. Like SARS-CoV and MERS-CoV, the newly detected coronavirus (SARS CoV-2) has a zoonotic source, however, human to human transmission has been confirmed. On March 11, 2020 the WHO declared COVID-19 viral disease a pandemic.
Epidemiology of COVID-19
As of July 23, 2021 total of 192,735,392 confirmed cases caused by the novel Coronavirus COVID-19 (SARS-CoV-2) and 4,139,009 deaths were reported. For a full listing of affected countries refer to Coronavirus (COVID-19) Global Cases (Johns Hopkins University)
The first human infections in China must have occurred in November 2019 or earlier. The first 59 suspected cases at the end of December 2019 and early January 2020 were admitted to Jinyintan Hospital, which was specially designated to isolate them.
On January 23, 2020, Chinese authorities closed off the city, canceling planes and trains leaving Wuhan and suspending buses, subways and ferry services. A second city in China, Huanggang was also placed in lockdown. On January 24, 2020 travel was restricted to a total of 10 cities, affecting 50 million people. Public bus, railway and airline operations were also suspended in these cities. On January 30, 2020 the World Health Organization (WHO) announced that the novel coronavirus is considered a public health emergency of international concern (PHEIC). The International Health Regulations Emergency Committee announcement this decision due to concern for further global spread after person-to-person spread of the novel coronavirus (COVID-19) was confirmed in 4 countries (Germany, Japan, Vietnam and the United States) outside of China. As for February 5, 2020, forty major airlines around the world have canceled or reduced their flights to China until as late as March amid the coronavirus outbreak. On February 19 and 21, 2020; cases were reported in Iran and Italy respectively with no known direct link to Mainland China. On March 9, 2020 Italy expanded the quarantine from the Lombardy region to the entire country, as Italy’s case count surged. People throughout the country of 60 million were ordered not to travel other than for work or emergencies. South Korea and Iran have also imposed travel restrictions. On March 11, 2020 the WHO declared COVID-19 viral disease a pandemic. As of March 25, 2020 the virus had spread to 192 countries with travel bans and restrictions implemented in many countries combined with various social distancing measures (ie. school, public space closures) in an effort to slow COVID-19 spread and flatten the epidemiological curve.
Preliminary calculations for the average number of infections that each infected person may go on to cause, known as R0. This is estimated to be 2.0 to 3.0 people per infected person. In comparison to seasonal flu, which usually has an R0 of around 1.3.
The World Health Organization announced that the fatality rate in Wuhan, China, considered the epicenter of the outbreak, is between 2% and 4%. Outside of Wuhan, it is thought to be closer to 0.7%. In a recent JAMA paper The overall case-fatality rate was 2.3%. No deaths occurred in those aged 9 years and younger, in those aged 70 to 79 years had an 8% fatality rate and those aged 80 years and older had a fatality rate of 14.8%. Children made up a 2.4% of the cases and almost none was severely ill. The fatality rate was 49% among critical cases, and elevated among those with preexisting conditions: 10.5% for people with cardiovascular disease, 7.3% for diabetes, 6.3% for chronic respiratory disease, 6% for hypertension, and 5.6% for cancer.
A conjoint review done by WHO and Chinese scientists has found that 80% of infected people had mild to moderate disease, 13.8% had severe symptoms, and 6.1% had life-threatening episodes of respiratory failure, septic shock, or organ failure. No deaths were reported among mild and severe cases. For the mild and moderate cases, it took 2 weeks on average to recover.
Surveillance for COVID-19 Infection
Provincial/Territorial public health authorities should report confirmed and probable cases of COVID-19 nationally to the Public Health Agency of Canada within 24 hours of their own notification.
A person with confirmation of infection with SARS-CoV-2 documented by:
The detection of at least 1 specific gene target by a validated laboratory-based nucleic acid amplification test (NAAT) assay (e.g. real-time PCR or nucleic acid sequencing) performed at a community, hospital, or reference laboratory (the National Microbiology Laboratory or a provincial public health laboratory)
The detection of at least 1 specific gene target by a validated point-of-care (POC) NAAT that has been deemed acceptable to provide a final result (i.e. does not require confirmatory testing)
Seroconversion or diagnostic rise (at least 4-fold or greater from baseline) in viral specific antibody titre in serum or plasma using a validated laboratory-based serological assay for SARS-CoV-2
A person who:
1. Has symptoms compatible with COVID-19
Had a high-risk exposure with a confirmed COVID-19 case (i.e. close contact) or was exposed to a known cluster or outbreak of COVID-19
Has not had a laboratory-based NAAT assay for SARS-CoV-2 completed or the result is inconclusive
Had SARS-CoV-2 antibodies detected in a single serum, plasma, or whole blood sample using a validated laboratory-based serological assay for SARS-CoV-2 collected within 4 weeks of symptom onset
2. Had a POC NAAT or POC antigen test for SARS-CoV-2 completed and the result is preliminary (presumptive) positive
3. Had a validated POC antigen test for SARS-CoV-2 completed and the result is positive
Symptoms of COVID-19
Illnesses associated with the new coronavirus, named COVID-19, are similar to several respiratory illnesses and include fever, dry cough, sore throat and headache. Less frequent symptoms included coughing sputum or blood, headache and diarrhea. Most cases are considered mild to moderate with a subset experiencing more severe illness with shortness of breath and difficulty breathing.
Reported signs and symptoms include:
Pneumonia in both lungs
Sudden loss of taste or smell
Treatment and Vaccine for COVID-19
Currently, remdesivir (brand name Veklury) is currently the only drug authorized with conditions to treat COVID-19 in those who are hospitalized with severe symptoms. For more information about treatment click here.
On Nov. 18, Pfizer released updated results of its Phase 3 clinical trials, suggesting the vaccine is 95 per cent effective at preventing COVID-19, a little over a week after releasing interim results showing the vaccine may be 90 per cent effective. Moderna announced on Nov. 16 that preliminary data from its ongoing Phase 3 clinical trial shows the vaccine is 94.5 per cent effective at preventing COVID-19. On Nov 23, Astra Zeneca announced their vaccine appeared to be 70 per cent effective against the novel coronavirus. On Jan 21, 2021 Johnson and Johnson announced their vaccine was 85% effective overall in preventing severe disease and demonstrated complete protection against COVID-19 related hospitalization and death as of day 28. For more information on COVID-19 vaccines click here.
Infection Prevention and Control
Prior to any patient interaction, all healthcare workers (HCWs) have a responsibility to assess the infectious risk posed to themselves and to other patients, visitors, and HCWs. This risk assessment is based on professional judgment about the clinical situation and up-to-date information on how the specific healthcare organization has designed and implemented engineering and administrative controls, along with the availability and use of personal protective equipment (PPE).
Recommendations for infection prevention and control measures for patients presenting with suspected or confirmed infection or co-infection with COVID-19 in acute care settings include:
1. Routine Practices: For all patients, at all times, in all healthcare settings including when performing a point-of-care risk assessment, and adherence to respiratory hygiene and hand hygiene.
2. Contact and Droplet Precautions(should be implemented empirically):
Wear gloves and a long-sleeved gown upon entering the patient's room, cubicle or designated bedspace.
Wear facial protection (surgical or procedure mask and eye protection, or face shield, or mask with visor attachment) when within two metres of a patient suspected or confirmed to have COVID-19 infection.
3. Airborne Precautions: When performing aerosol-generating medical procedures (AGMPs). A respirator and face/eye protection should be used by all HCWs present in a room where an AGMP is being performed on a patient suspected or confirmed to have COVID-19 infection. Whenever possible, AGMPs should be performed in an airborne infection isolation room.
As information becomes available, these recommendations will be re-evaluated and updated as needed.
Variants of the Virus that Causes COVID-19
Genetic variations of viruses such as the one that causes COVID-19 are not uncommon and many other variants of the SARS-CoV-2 virus have been previously observed around the world this year. Both new variants include mutations (i.e., changes to the genetic material in the virus) on the “spike” protein, which may result in the virus becoming more infectious and spreading more easily between people. These variants have been termed variants of concern (VOCs) and have been associated with evidence of increased transmissibility, severity, and/or possible immune evasion with potential implications for reinfection and vaccine effectiveness
Multiple variants of the virus that causes COVID-19 are circulating globally:
The United Kingdom (UK) identified the alpha variant (B.1.1.7) with a large number of mutations in the fall of 2020. This variant spreads more easily and quickly than other variants.
In South Africa, another beta variant (B.1.351) emerged independently of B.1.1.7. Originally detected in early October 2020, B.1.351 shares some mutations with B.1.1.7.
In Brazil, the gamma variant (P.1) emerged that was first identified in travelers from Brazil, who were tested during routine screening at an airport in Japan, in early January. This variant contains a set of additional mutations that may affect its ability to be recognized by antibodies.
In India, the delta variant (B.1.617) was first detected in December 2020. It remained rare until early March, when it became the dominant variant reported. It
For more information of COVID-19 Variants of Concern, click here.