WHAT IS COVID-19

Introduction

COVID-19 is an infectious disease caused by a new virus. The disease causes acute respiratory illness. Medically, it is known as coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 virus emerged in December 2019 in China and spread worldwide, with currently more than 469 212 705 confirmed cases and 6 077 252 deaths (as of March 21st, 00:00 UTC +0)¹. At the time of writing, there are no specific vaccines or treatments for COVID-19, but there are many ongoing trials evaluating potential treatments.

What are coronaviruses?

Coronaviruses are enveloped, single-stranded large RNA viruses that infect humans, as well as a wide range of animals. The name comes from the Latin term for a crown (corona) due to its morphology as a spherical virion with a core shell and surface projections resembling a solar corona.

COVID-19 is the third known zoonotic (spread from animals to humans) coronavirus disease after the outbreaks of the Severe Acute Respiratory Syndrome (SARS) in 2002/2003 and the Middle East Respiratory Syndrome (MERS) in 2012².

Origin of SARS-CoV-2

The most recent coronavirus spread is thought to originate at the Huanan Seafood Wholesale Market, where the transmission chain likely started from bats to humans³. Since then it has spread all over the world, transmitting from person to person, resulting in 237 countries, areas or territories reporting confirmed cases of COVID-19¹.

Symptoms of COVID-19

COVID-19 a respiratory disease with the following symptoms⁴:

• Fever
• Tiredness
• Dry cough
• Shortness of breath
• Aches and pains
• Sore throat
• Diarrhea, nausea or a runny nose (less common)

Most infected people develop mild to moderate symptoms and recover without needing special treatment. However, some people, including the elderly and people with previous medical issues (such as diabetes, cardiovascular disease, chronic respiratory disease, cancer) are at higher risk of developing severe symptoms that could ultimately lead to death.

Prevention

The SARS-CoV-2 virus spreads primarily through droplets of saliva and mucus from the ​mouth and ​nose when an infected person coughs or sneezes. To prevent the spread of this virus, social distancing is highly encouraged. When in contact with other people, proper respiratory etiquette is essential (sneezing/coughing into a tissue or a flexed elbow). An infected person can lessen the viral spread by wearing a medical mask. The goal of a mask covering the nose and the mouth of an infected person is to block the infected droplets ​from spreading. However, it does not completely protect an uninfected person from catching the disease – only a respirator equipped with a proper filter can properly protect from the infection^5,6.

Recent research shows that this virus could survive for several days on various surfaces⁷. To avoid contracting the virus, it is crucial to avoid touching your face and wash your hands regularly with soap or alcohol-based hand-rub.

References

• ¹ - https://covid19.who.int/ (updated March 21st 00:00 UTC+0)
• ² - Chen, Y, Liu, Q, and Guo, D (2020). Emerging coronaviruses: Genome structure, replication, and pathogenesis. J Med Virol 92, 418–423.
• ³ - Li, Q et al. (2020). Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus–Infected Pneumonia. N Engl J Med 328, 1199–1207.
• ⁴ - https://www.who.int/health-topics/coronavirus#tab=tab_3 (cited on 04/01/2020)
• ⁵ - https://www.who.int/health-topics/coronavirus#tab=tab_2 (cited on 04/01/2020)
• ⁶ - https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public/when-and-how-to-use-masks (cited on 04/01/2020)
• ⁷ - van Doremalen, N et al. (2020). Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. N Engl J Med, NEJMc2004973.