With predictions of coronavirus causing almost two million cases and up to 120,000 deaths in Ireland, it is understandable that public concern is growing.
However, it is important to appreciate that these are modelling exercises subject to all the shortcomings of any theoretical work. Since we have yet to see the full details of these estimates, we do not know what assumptions are made and whether proper account is being taken of any control measures taken to limit the spread of the disease.
In the real world, public health doctors have to base their actions on the information available about the virus – how it spreads, how lethal it is, how it behaves in the community and so on. The measures they take can have a significant impact on outcomes.
Since our knowledge of Covid-19 dates back only a few months, there are understandable limits to what we know, even if new research data is coming in daily.
What we do know – or think we know – suggests that some measures we could take work better than others. We know, for example, that coronavirus is highly transmissible. Within two months, it has spread virtually around the entire world.
That suggests that in trying to contain its spread we should take steps to limit the kinds of environments that facilitate this transmission. On an individual level, this means social distancing; to maintain 1-2m from others, beyond coughing and sneezing distances.
On a societal level, it suggests we have to limit gatherings of large numbers of people in confined spaces. This is why the St Patrick’s Day parades have been cancelled – as much due to the after-parade festivities as any proximity that might occur during the outdoor events themselves.
It is also why, for a time, we will have to cancel or postpone many other events that bring people too closely together, thereby facilitating the spread of the disease.
Within families
It is worth noting, however, that the data from China indicates relatively little transmission of the disease in the community; instead, most cases, especially in the early stage, spread within families.
Equally, there does not seem to be much evidence of infected travellers transmitting the disease to large numbers of fellow travellers or, as one scientist put it: “We’re not seeing whole plane-loads of people come down with this.”
This should give cause for some optimism about our ability to control the spread of the disease, provided people practise proper hygiene and keep out of the way of others showing flu-like symptoms.
The limited evidence available also suggests it may not be necessary to shut schools unless the situation deteriorates seriously. We know already that young people are largely spared the ill-effects of Covid-19.
That does not mean they could not play a role in passing it on to other, more vulnerable people. But World Health Organisation (WHO) experts who visited China found that, more often, it was parents who passed the virus to their children, rather than the other way round.
However, schools may still be affected if large numbers of teachers fall ill.
And while thousands of healthcare workers in China caught the virus and many died, often the WHO found this happened after they were infected at home rather than in hospitals. So this, too, gives us hope the spread of disease in hospitals can be controlled.
Hot theory
Many people are banking on the arrival of warmer weather to see the virus off. This ignores the fact that substantial Covid-19 outbreaks have occurred in hot countries such as Singapore.
On the other hand, the flu is worse in winter as much because we’re cooped up together when the days are short because of the outside temperature.
"We have no reason to believe that this virus would behave differently in different temperatures, which is why we want aggressive action in all countries to make sure that we prevent onward transmission, and that it's taken seriously in every country," WHO head of emergencies Dr Mike Ryan said last week.
The point of these shards of information is that there are measures we can take that may make a difference, while other possible options could be deferred for now.
Most of all, we need to test people quickly and isolate confirmed cases as quickly as possible. That needs a huge effort in tracing contacts of those cases.
We know the virus is going to hit us hard in the coming weeks, as it has other countries. The more we do in terms of effective countermeasures, the shorter and smaller this peak will be. We can “flatten the curve” and push it forward a bit into the future.
After all, China is well past the worst, and the virus seems to have peaked in South Korea and perhaps Italy, too. There is hope.