Coronavirus: Big problem now a series of smaller ones and there could be nasty surprises
Crystal clear that physical distancing works as a mechanism for slowing spread of virus
A Defence Forces medic awaits arrivals at the testing site on Sir John Rogerson’s Quay, Dublin. File photograph: Niall Carson/PA
Public health officials tackling the Covid-19 pandemic are like firefighters trying to bring a large blaze under control.
What seems at first to be one large, uncontrollable fire is eventually, by dint of hard work, split into several smaller, more manageable fires.
But as firefighters try to completely extinguish one fire, they risk another roaring back into action because resources have been diverted away from tackling it.
In this vein, we started with a monolithic coronavirus challenge with an unpredictable trajectory.
Through the various measures brought in to restrict the spread of the disease, we can now see that what was formerly a single problem has become a collection of different but smaller challenges.
For example, we had a problem with imported cases of Covid-19, but with the curbs on travel that has now diminished in importance.
From the start, we have clearly had a problem with the spread of infection within hospitals. Hundreds of staff have been infected and hundreds more have been forced into self-isolation through contact with cases. This in turn put the remaining staff under even more pressure.
But only one-quarter of these cases among healthcare staff arose from transmission between workers and patients. The rest got the disease in the way everyone else did, through community transmission or travel abroad.
This means the restrictive measures imposed on everyone, and the reduction in foreign travel, will positively reduce cases among healthcare workers along with the rest of the population.
As for transmission between staff and patients, much of this arose because staff were insufficiently protected against infection during interactions with patients. This isn’t all about protective gear; it also relates to distancing and hand hygiene.
By now, awareness of the dangers of the virus being transmitted from patients without symptoms, or from surfaces, is much higher than it was a month ago. So again, the number of cases arising in this way should be reducing with time. The Mater hospital in Dublin, for example, has suffered comparatively few infections among staff thanks to strict personal protection equipment and patient cohorting policies.
Clusters account for about one-fifth of confirmed cases, and increasingly they are occurring in residential settings such as nursing homes, hospitals, residential institutions and community hospitals/long-stay units.
This is bad, because many residents are elderly or have underlying conditions. As a result, we will have more deaths.
However, residents, outside hospitals, are not generally mobile and are unlikely to transmit the disease further. Common sense suggests a closer look at the movements and practices of staff in these institutions will yield results.
In contrast to the problems in residential settings, public health officials have found just four clusters they classify as community outbreaks and only tiny numbers in workplaces, pubs and hotels.
It is abundantly clear from international evidence at this stage that social distancing works as a mechanism for slowing the spread of this virus.
Equally, it is clear that the widespread adherence to the social distancing measures implemented in Ireland has worked to curb the spread of disease here.
We have seen the rate of growth of new cases fall from 33 per cent a day to under 10 per cent since the restrictions were introduced. Counting new cases is an unreliable metric given its link to the amount of testing being done, and the problems that have arisen in this area, but at least it’s comforting that the trend is in the right direction.
A better way is counting admissions to intensive care. However, published figures on intensive care unit (ICU) admissions have been scant so far; indications are that this number has stabilised after passing the 138 mark.
Another way of measuring our progress is counting deaths. These hit 22 last Friday, but totals for the last three days have been lower. While it is hard with such small numbers to start mapping a curve there is no sign as yet of an exponential rise in deaths, and this despite the problems in nursing homes where the oldest and most exposed population are at risk.
So where does this leave us? Well, we know the big problem is now a series of smaller problems. We know where a lot of the issues are. One caveat: the lack of general testing means there could be nasty surprises out there that we just haven’t yet found.
On Tuesday, researchers in the US estimated Ireland had already passed its peak for ICU admissions and deaths, a finding that may surprise many. Our own National Public Health Emergency Team has held its projections closely to its chest so far. Perhaps, early on in this crisis, it did not want to scare people; now, it may not want to breed complacency.
The public health emergency team has also done modelling on the economic impact of the nationwide shutdown relative to health benefit but again it hasn’t yet released its findings.
We don’t need a forecaster to tell us how big this impact is, but we do need a road map for reducing it – particularly if other trends are pointing the right way.