Published 13 March 2020
You’ve got a cough. Not surprising: it’s one of the most common health complaints around the world and can have a seemingly endless list of causes – from allergies to lung cancer to pneumonia. And when an infectious disease is involved, pinpointing the exact cause is critical to not only determine the right treatment but also to understand how contagious the infection is and how it can be spread.
In China, the COVID-19 outbreak also started with a cough as one of its main symptoms. But its specific cause was something never before seen in humans. Existing laboratory tests weren’t able to identify the virus, which meant doctors could only guess which treatments to prescribe and the preventive measures to take. Health authorities weren’t even sure exactly where and how the virus originated.
Research eventually determined that the disease was a new (novel) strain of coronavirus – a large family of viruses that cause illnesses ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV). Coronaviruses are zoonotic, meaning they are transmitted between animals and people.1
From initial outbreak to global pandemic
Because this was a new virus, nobody knew exactly how quickly the disease could be transmitted or how severely it would affect those infected. But as the outbreak unfolded, its lethal potential quickly became apparent. With no effective treatment, isolation became the most common form of containment. These measures helped but didn’t stop COVID-19’s inexorable march from city to city, then region to region, and ultimately country to country.
This novel coronavirus outbreak has affected more than 120,000 people worldwide and has since been classified as a pandemic by the World Health Organization (WHO). And the number of known cases continues to rise − it can now be found on every continent except Antarctica.2
While the virus is deadly for some, causing pneumonia, severe acute respiratory syndrome or kidney failure, many who have it experience mild symptoms or no symptoms at all, making it much harder to detect and contain. It infects people of all ages. However, evidence to date suggests that two groups of people are at a higher risk of getting severe infections: older people and those with underlying medical conditions. WHO emphasises that everyone should protect themselves from COVID-19 in order to protect others.3
COVID-19 is now occurring in some countries more quickly than it did in China, meaning that minimising the disease’s reach and impact has become a race against time. Italy has had the greatest number of confirmed cases − and deaths − in Europe; the number of confirmed cases in the US has exceeded 1,000. However, public health experts have voiced their concern that the current number of cases, particularly in the US, is inaccurate because too few people have been tested.
Keeping coronavirus in check
Broad access to reliable COVID-19 testing is essential to accurately identify who has been infected and to contain the disease. “All countries must aim to stop transmission and prevent the spread of COVID-19, whether they face no cases, sporadic cases, clusters or community transmission,” said Dr. Tedros Adhanom Ghebreyesus, WHO Director-General.4
Medical researchers and health system authorities have been collaborating together closely to ensure that tests are developed, reviewed and made available to as many people in as many countries as possible. Because COVID-19 attacks the respiratory system, test samples need to be collected via a nasal or throat swab. The tests also need to ensure that the samples can be handled safely and not contaminate the testing equipment or put laboratory staff at increased risk of catching the disease themselves.
As healthcare professionals and regulatory authorities gain more knowledge about the disease, lessons have emerged that can be applied to future disease outbreaks. Infectious diseases don’t respect national boundaries − everyone needs to work together to understand, contain and treat the outbreaks. Information needs to be shared early and freely. And, importantly, accurate and reliable diagnostic tests are essential to determining the extent of the outbreak and to identify those most vulnerable.
“You can’t fight a virus if you don’t know where it is. That means robust surveillance to find, isolate, test and treat every case, to break the chains of transmission,” Dr. Ghebreyesus said.
If you want to find out more about COVID-19 and get the latest information on the pandemic, please visit the WHO website:
1. World Health Organization. Health Topics: Coronavirus. [Internet; cited 2020 Mar 12]. Available from:
2. World Health Organization. Novel Coronavirus (COVID-19) Situation. [Internet; cited 2020 Mar 12]. Available from:
3. World Health Organization. Situation Report - 51: Coronavirus Disease 2019 (COVID-19) [Internet; updated 2020 Mar 11]. Available from:
4. World Health Organization. Mission Briefing on COVID-19: WHO Director-General’s Opening Remarks. [Internet; cited 2020 Mar 12]. Available from: