The short answer is yes, it is possible to be a ‘silent carrier’ of the coronavirus. But scientists aren’t yet sure how common this is, nor exactly how it’s affecting the spread of the disease.
Here’s what you should know
A dry cough. A sore throat. Fever and shortness of breath. These are the most common signs that you might have contracted the novel coronavirus that’s spreading rapidly across the globe. However, not everyone who catches the virus develops this neat list of symptoms.
In fact, some people may have symptoms so mild they don’t even notice. And others won’t show any symptoms at all.
“The complete clinical picture is still not fully clear,” explains South Africa’s National Institute for Communicable Diseases (NICD). Because this coronavirus' presence in humans is only a few months old (the first case was reported in China in December 2019), scientists are still gathering the data they need to build a clear picture of how it spreads and behaves. So we don’t yet know for sure why some people with the virus experience no symptoms, although studies have shown that this is the case for other viruses, such as the flu.
How many people are ‘asymptomatic’?
We also don’t yet know what percentage of people are ‘asymptomatic’, which means they are infected by the virus, but display none of the telltale signs. Because it’s not widely feasible to test large groups of people without symptoms (the strain on healthcare facilities is simply too high), and because COVID-19 science is still in its early days, any number is at best an area-specific estimate.
A study from China indicated that as many as six out of 10 people who contracted the virus in Wuhan were asymptomatic. In Iceland, where more of the population has been tested for COVID-19 than in any other country so far, 50 percent of people who were positive showed no symptoms at the time of their tests.
Based on these numbers, it seems likely that a fairly significant number of people who catch the coronavirus might never even know about it. However, it’s also important to note that many people initially believed to be asymptomatic just hadn’t developed their symptoms yet.
What is the difference between ‘asymptomatic’ and ‘pre-symptomatic’?
Asymptomatic people test positive for the virus but never go on to develop symptoms. ‘Pre-symptomatic’, on the other hand, defines those who don’t have symptoms at the time they test positive but do later get sick. This is because the virus has an incubation period of about two weeks – the time after it has infected your body but before you start to show symptoms.
Can you spread the virus if you don’t have symptoms?
“The risk of catching COVID-19 from someone with no symptoms at all is very low,” reports the World Health Organisation (WHO). This is because the main way the virus spreads is via respiratory droplets expelled by someone who is coughing or sneezing. If you’re not coughing or sneezing, you’re not likely to pass it on. But take heed: ‘very low’ is not the same as ‘impossible’. You might sneeze without feeling sick and think nothing of it. Your droplets might carry the virus, whether you’re asymptomatic or pre-symptomatic.
This is why it’s so important to practice good ‘respiratory hygiene’ and social distancing even if you’re feeling quite well. Cough and sneeze into the inside of your elbow or a tissue, dispose of the tissue immediately, and wash your hands.
What if I did have a mild or asymptomatic case of COVID-19?
Speaking to The Guardian in an article dated 5 April, 2020, Dr William Hillmann, associate inpatient physician director at Massachusetts general hospital, explained that there is currently no test to establish if you’ve had the virus in the past. Scientists are working on an antibody test to establish prior infection, but they’re not yet available to the public.
If you did have an asymptomatic or very mild case of the virus without ever knowing, there’d be no real risk to your health. Your body would simply have flushed it out as it does with many other viruses on a fairly regular basis.
If you suspect you might have the COVID-19 virus, call your healthcare provider. Calling ahead prevents you from spreading – or being infected by – the coronavirus and allows your healthcare provider to direct you to the right facility.