London - The worst aspect of the spread of Covid-19, for those of us not infected, is the anxiety arising from our lack of knowledge about it.
Coronaviruses were first discovered in the Sixties. They tend to cause respiratory symptoms, and if you’ve ever had a heavy cold or flu-like episode, you’ve likely been infected with some type of human coronavirus.
The current epidemic involves the third strain to jump from animals - probably bats - to humans since 2000. The first was Sars (severe acute respiratory syndrome), then Mers (Middle East respiratory syndrome).
Knowing that some people die from the resulting disease, Covid-19, is frightening, and we worry for ourselves and for those close to us.
Currently we know that about one percent of those affected will die - but it will only be when we look back in six or 12 months that we’ll see informed and balanced evidence. We know the virus can be caught from someone who is infected, but not yet ill with symptoms, which is also the case with many illnesses.
Those with a low-grade infection will not be treated and will continue about their daily life unaware, potentially spreading the virus to others.
So who should worry? A virus that is a small risk to most people is a big risk to anyone dealing with other health problems, so the answer is: those already unwell, older people with existing conditions such as diabetes or heart disease, and smokers.
The virus targets cells lining the lower respiratory tract, which in smokers are already on the back foot as they battle the daily influx of toxins from tobacco or vape smoke.
You cannot help it if you are already ill, but if you smoke, you must stop immediately.