As Nigeria continues to battle with the outbreak of the deadly coronavirus, researchers say the deadly bug could already have infected more people than have been reported.
This has left many people wondering whether they might have actually already had coronavirus – particularly when they show symptoms of cold or respiratory illness.
There are also some lesser-known mild symptoms that a number of those later diagnosed with coronavirus have reported experiencing.
Here, we take you through some of the signs that may indicate you already had coronavirus earlier this year…
1. A dry cough
A dry persistent cough is a ‘classic’ symptom of coronavirus, according to Dr Sarah Jarvis, GP and Clinical Director of Patientaccess.com.
She says a dry persistent cough is normally new for you (or different from your normal cough if, for instance, you have a ‘smoker’s cough’).
It’s also persistent – not just because you’re clearing your throat or because you have something caught in your throat – and it needs to last for at least half a day.
A dry (rather than ‘fruity’ cough) is more likely to be due to coronavirus, but you need to self-isolate regardless of whether your cough is dry or productive.
A “dry cough” is a cough where no phlegm or mucus is produced, which is also irritating and usually associated with a tickly throat.
2. A high temperature
A fever is a key symptom of coronavirus, experts say.
They say you don’t need to fixate on a number, but know it’s really not a fever until your temperature reaches at least 100 degrees Fahrenheit (37.7 degrees Celsius) for children and adults.
They say you can tell if you have a fever when you feel hot to touch on your chest or back.
3. Shortness of breath
Shortness of breath can be a third – and very serious – manifestation of Covid-19, and it can occur on its own, without a cough.
If your chest becomes tight or you begin to feel as if you cannot breathe deeply enough to get a good breath, that’s a sign to act, experts say.
Patients who are usually older or have a pre-existing health condition are normally the people who experience difficulty breathing – known as dyspnea.
Signs that a person is experiencing dyspnea include shortness of breath, feeling smothered or suffocated, tightness in the chest, rapid, shallow breathing, heart palpitations and wheezing.
4. Stomach ache
If you had a bad stomach earlier this year you might have just had a bug like norovirus.
But some Covid-19 patients have reported experiencing tummy ache just before developing the other known symptoms.
A new study, published in the American Journal of Gastroenterology, suggests people might experience digestive issues, such as diarrhoea, when they are infected with coronavirus.
Researchers analysed data from 204 patients with Covid-19 in China’s Hubei province and they discovered that 48.5 per cent of these patients arrived at the hospital with digestive symptoms such as diarrhoea, vomiting or abdominal pain.
5. Loss of taste/smell
If you previously lost your sense of taste and smell you could have already had coronavirus.
The British Association of Otorhinolaryngology says patients who do not have a fever or a cough could show a loss of smell or taste after contracting the deadly bug.
In a statement, the docs said: “Evidence from other countries that the entry point for the coronavirus is often in the eyes, nose and throat areas.
“We have also identified a new symptom (loss of sense of smell and taste) that may mean that people without other symptoms but with just the loss of this sense may have to self-isolate – again to reduce the spread of the virus.”
It’s thought that losing the ability to smell or taste could be due to the virus destroying cells in the nose and throat.
6. Brain fog
Some people may experience brain fog, also known as mental fatigue, as another symptom of coronavirus.
It’s not been officially looked into as a symptom but it’s another indicator that those who have experienced the illness have reported experiencing.
Thea Jourdan, 50, said she didn’t experience a cough or fever – instead, her introduction to Covid-19 began with a tickle in her throat and a dull headache.
The mum-of-three, from Hampshire, UK says she then started to experience brain fog.
She told the Daily Mail: ” I had brain fog. I was unable even to fill out forms from the children’s schools. I just wanted to sleep.”
Another symptom that coronavirus patients have reported is feeling extremely fatigued before symptoms develop.
According to a report in the Journal of the American Medical Association, up to 44 per cent of those hospitalised with Covid-19 reported exhaustion and fatigue.