Why Are Covid-19 Cases High, But Deaths Remain Quite Low?

Every Monday we’ll answer your questions on Covid-19 and health in a feature published online. You can submit a question here.

This week, HuffPost UK reader Jason asked: “Why are cases rising, but the death rate remains so low?”
The UK has been witnessing around 50 deaths a day from Covid-19 (sometimes less) – and while this is already far too many, people have noticed the number of deaths seems disproportionate to the recent rise in cases, of which we’re now averaging about 9,700 a day.
For context, at the height of the pandemic, we saw more than 1,000 deaths in a day, but only 5,100 recorded confirmed cases. 
Over the past few weeks we’ve watched as cases have almost doubled on a weekly basis. Deaths have risen slowly and steadily, but – on the whole – remained relatively low. So, why is this?
There are a few factors at play here, say scientists. Let us break them down.Submit a Coronavirus health question to HuffPost UK.Related... Your Self-Care Toolkit For Dealing With The Tough Months Ahead Testing is more widely availableIn March, we saw lower levels of Covid-19 recorded to what we have now, says Dr Stephen Griffin, associate professor in the School of Medicine at University of Leeds. But back then, we were only testing those who were very unwell – predominantly those hospitalised with the virus. “So they were the tip of the iceberg and the most severe cases,” he says.
It’s likely we had far more cases in March than we do now – they just weren’t recorded, as testing wasn’t widely available. “Now, we have testing in the community, as well as at hospital,” says Dr Griffin, “so the number we have in tests is a greater proportion of the number of cases that we’re actually seeing.
“Proportionately, back in spring, it would’ve seemed as though there were far more fatalities in relation to the number of tests coming back positive.”
Now, we have a better grasp of data and a fairer picture of how the virus is impacting our communities broadly – not just those with the most severe symptoms. We’re getting better at protecting othersWe’re also seeing more precautions taken to protect the most vulnerable members of society. This includes regular hand-washing, wearing face masks in public settings and keeping 2m away from others. 
On top of that, some families will be limiting their contact with others in order to be able to spend time, safely, with vulnerable family members.Related... Why 'Chain Of Trust' Is The Next Covid-19 Term You Need To Know About We’ve actually got treatments nowDr Griffin points out there are better ways of treating people now. “You get admitted, you’re on a ward, there are measures we can now put in place to hopefully stop you developing a really bad disease and having to go to intensive care,” he explains.
“And of course, if you’re in a really bad way and you’re on a respirator in intensive care, we also have the option of treating you with steroids – but that only works when you’re at the nasty end of Covid.”
There are various treatment trials underway across the UK, meaning current Covid-19 patients can receive antibody rich blood plasma from previous Covid patients as well as other options. This might also be having some effect.
As cases rise, we will inevitably see more fatal cases, says Dr Griffin. Typically we’re seeing a lag of a few weeks between people testing positive for the virus, then a bump in hospitalisations, and then a bump in deaths.Related... What It's Like To Receive Blood Plasma To Treat Covid-19 The virus is spreading among younger peopleAnother factor likely contributing towards fewer deaths is that those testing positive have predominantly been young, wealthy white people. The rise appears to correlate with people going out and socialising more in pubs and restaurants, but also mixing at home. 
The chances of becoming severely ill with the virus is less likely the younger you are, so it would make sense there are fewer deaths as cases in this group rise. But Dr Griffin says we shouldn’t just look at fatalities – “we know this virus can cause profound, long-lasting issues,” he says, referring to the 600,000 people in the UK suffering with long Covid. So far, studies have shown the virus can cause damage to the heart, lungs, and other areas of the body. So there is still a risk among younger age groups.
One of the biggest worries is that young people may be fuelling the spread among their parents and grandparents. Data from September 30 showed the number of over-65s admitted to hospital or intensive care with coronavirus was rising sharply – and this is a worry.
There are concerns over what happens if the virus spreads through care homes again. Professor Rowland Kao, an expert in data science at the University of Edinburgh, points out that care homes drove the deaths in the early phase, but are not yet a factor in the more recent rise.
“The worry is that, as the epidemic now is increasing exponentially, we’ll see in a few months more deaths, but also a greater probability of infection jumping into the care homes,” he says, “and therefore higher death rates there as well.” Related... When Will Routine NHS Dentist Appointments Return To Normal? The virus is the same strengthThere are some theories that the virus has weakened in strength and is not as deadly anymore. As far as scientists can tell, this is not the case.
Speaking at a recent press conference, the government’s scientific adviser Sir Patrick Vallance said explicitly: “The virus has genetically moved a bit but it has not changed in terms of its propensity to cause disease and deaths.”
Dr Griffin fiercely agrees that the virus hasn’t mutated to become weaker or less deadly. While viruses do change gradually over time, he points out that coronaviruses don’t change as rapidly as, for example, the flu. There are no indications that there is less virulence of the virus, he says.
Experts are still learning about Covid-19. The information in this story is what was known or available at the time of publication, but guidance could change as scientists discover more about the virus. To keep up to date with health advice and cases in your area, visit gov.uk/coronavirus and nhs.uk.Related... What Are Super-Spreader Events – And How Can You Avoid Them? The Science Behind Why Singing Could Spread Coronavirus I’m Worried How Growing Up In A Pandemic Will Affect My Baby