1. Definition and Cause
- COVID-19 is an infectious respiratory illness caused by the coronavirus SARS-CoV-2, first identified in Wuhan, China, in December 2019.
2. Transmission
COVID-19 spreads through:
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Respiratory droplets (coughing, sneezing, talking)
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Close contact (within 6 feet)
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Contaminated surfaces and objects.
3. Symptoms
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Fever
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Cough
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Fatigue
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Shortness of breath
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Loss of taste/smell
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Muscle pains
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Diarrhoea.
Note. Amongst those who develop noticeable symptoms, most (about 80%) experience mild symptoms; whilst 15% develop more severe symptoms, and 5% experience serious illness.
4. Incubation and Duration
- Incubation – symptoms appear within 5-6 days (range 2-14) after exposure
- Duration
- Mild cases usually resolve in 1-2 weeks
- It may take up to 6 weeks or more to recover from severe COVID
- In long COVID, symptoms last more than 3 months.
5. Vulnerable Populations
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Older adults (65+)
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Young children
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Underlying health conditions (diabetes, heart disease)
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Immunocompromised individuals.
6. Prevention
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Vaccination
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Mask-wearing
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Social distancing (6 feet)
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Hand hygiene
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Avoiding crowded areas.
7. Vaccine Efficacy
- COVID-19 vaccines significantly reduce severe illness, hospitalisation and death.
8. Treatment
Most people with COVID-19 do not need any treatment. But for those that do, treatment may include:
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Medication (see below)
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Oxygen therapy
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Hospitalisation +/- ICU/ventilation (severe cases).
Antiviral Medication
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Remdesivir (Veklury): For hospitalised patients
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Lopinavir/Ritonavir (Kaletra): Often used with other medications
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Oseltamivir (Tamiflu): For influenza co-infection
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Molnupiravir (Lagevrio): Mild-moderate COVID-19
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Paxlovid (Nirmatrelvir/Ritonavir): Mild-moderate COVID-19.
Anti-Inflammatory Medication
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Dexamethasone: For severe cases
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Prednisone: For inflammation
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Tocilizumab (Actemra): For cytokine storm management.
Immunomodulatory Medication
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Baricitinib (Olumiant)
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Tofacitinib (Xeljanz).
9. Global Impact
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Over 776 million reported cases (12/24)
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Over 7 million reported deaths (12/24)
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Widespread economic disruption.
10. Mortality and Long COVID
- Mortality rate for COVID-19 is about 1%, but this varies greatly depending on vaccination status, age, variant, and underlying health conditions (e.g. heart disease, diabetes, chronic respiratory disease, and cancer)
- Mortality increases to 5% for those aged 75 and 15% for those aged 85
- Patients with very severe disease may require ventilation (a breathing machine) in intensive care, and in some cases, this can lead to death
- In a 2024 UK stydy. 3-5% of people developed Long COVID after an acute COVID-19 infection. In the UK, it affects an estimated 2% of the population, and 70% of people with the condition have now had it for more than a year.
Other information
Are pandemics new?
- Pandemics are not new. They are mentioned in historical texts, such as the Bible and the Quran. In 1918-20, the Spanish flu, an influenza virus, likely caused over 50 million deaths.
Is COVID-19 similar to seasonal flu?
- Yes and no. Both cause respiratory infections (affecting the upper airways and lungs), and the viruses that cause COVID-19 and seasonal flu spread between people in close contact
- Both are transmitted when infected individuals cough, sneeze, or talk. However, the virus that causes COVID-19 appears to spread more easily than influenza
- COVID-19 first appeared in late 2019 and spread rapidly across the globe. As SARS-CoV-2 was a new virus, most people had no immunity to it, meaning the entire human population was vulnerable to infection at the start of the pandemic
- It is difficult to know when an influenza virus first infected humans, but reports of flu pandemics go back hundreds of years. Influenza vaccines were first developed in the 1930s.
