The ups and downs of Covid-19
What do the numbers in the US tell us, how can we explain them?
YACA — Yet Another Covid Article? The reason I am writing one today is that there is a mysterious phenomenon that seems to have left many experts — even the US administration — puzzled. This week (end of June 2020) the number of infections in the US is rising steeply in a majority of the states. But at the same time the number of hospitalizations and especially of deaths is sinking. How can this be explained?
Well, I discussed this question a day ago with a virus research expert, a good friend who has been doing AIDS research for ten years, and is now working full time on trying to develop a vaccine for the new coronavirus. We discussed a number of possible explanations.
Testing
Is it the current increase in testing, in the US and elsewhere, that is inflating the numbers? Is increased testing simply revealing that many more people have contracted the disease than was previously assumed? Sure, that makes the stats look more threatening, but let us compare:
Germany has a population of 83 million, and has a very high level of testing (you can get a same-day test if you call 116-117 and report suspicious symptoms or contacts). In the city of Hamburg, Germany, where I live (population 1.9 million), the number of new infections per day now varies between zero and nine. This is a graph for the total number of infections in the whole of Germany:
South Korea, population 52 million, has done the most rigorous testing and tracking in the world. The country has recorded 12,650 infections and 282 deaths since the start of the pandemic (full stats for all countries are available here). In the same period the US, which is six times larger, has reached 2½ million infections with 130,000 deaths. That is 200 times more infections and 461 times more deaths.
Italy suffered the earliest and most severe coronavirus infection in Europe. It has a population of 60 million and has suffered a total of 34,716 covid deaths. But things have become better. Today today (June 27, 2020 ) Italy recorded 175 new infections and just eight deaths. On the same day Florida, which has a population of 20 million, had 9,585 new infections and 3,392 deaths. Here is a comparison of country of Italy and the state of Florida since the beginning of the pandemic:
All experts confirm; the gigantic and soaring US numbers cannot be explained as “Well, that comes from increased testing.” In Europe and Asia the rise in testing has not shown a rise in the number of people infected. In the US it hadn’t either — until the current time.
Infections vs deaths
Currently, in the US the number of infections is certainly rising, while the number of people dying from Covid-19 is sinking, slightly. Let us speculate why that isn the case:
- After the Memorial Day loosening of restrictions in the US four weeks ago, it was young people who most readily abandoned caution. They are stronger and for reasons we don’t yet fully understand are better able to deal with the new coronavirus. They seldom need hospitalization and very rarely succumb to the disease. That means they can increase the number of infections while not increasing the fatality numbers. The percentage of deaths in the total number of infections sinks.
- We must consider the fact that the quality of treatment has, over the months, most likely improved. Doctors now know better how to save the lives of people infected with Covid-19. So a larger percentage of people who show dangerous symptoms are being saved.
- We must also consider the following: it is possible that the virus has now decimated the most vulnerable segments of the population (e.g. elderly people in care homes), or has driven people to implement special measures to protect them. This could reduce the initial fatality numbers.
- Another factor we discussed was the role of evolution. We need to remember that the less harmful a virus is, the better it can be passed on. Viruses that cause serious sickness or death, ones that kills you quickly, have very little time to spread. People who are infected are rapidly isolated, or they die and are buried — together with the virus. It is the ones that cause mild symptoms, or none at all, at least for a while, that can spread merrily. There are in fact many beneficial viruses that actually improve human health. That makes them especially capable of spreading, even becoming a permanent part of our genetic code.
- It is conceivable that the novel coronavirus, SARS-Cov-2, is mutating and that a less virulent, asymptomatic strain is infecting a greater percentage of people, while the deadlier strain is being better isolated. My virus researcher friend considers this unlikely, since, he says, we would have genetically identified the new strain by now.
Delayed consequences
There is another explanation for the sinking deaths in the face of rising infections. Why are they not also rising? The answer is: they are not rising yet! They are still sinking. Let me explain:
On Memorial Day the country was “opened,” the lockdown revoked, social distancing eased. This effort to “return to normal” naturally led to the virus spreading faster, and the number of people catching it rose. Exact trends for the US and world-wide can be followed on the NYT page Coronavirus Map: Tracking the Global Outbreak.
So now there is a clear and undeniable rise in the number of infections, but we do not see an increase in the death rate for a simple reason: it is a matter of time. Covid-19 deaths always lag behind the infections.
The spread
Say you hold a rally, and 6,000 people from all over the country attend, most of them unmasked, shouting and screaming. Say, as some studies have suggested, 800 people become infected. They will go home, to different parts of the country, taking the virus with them. After five or six days some will begin coughing, feeling unwell (as happened to the daughter of a dear friend of mine, here in Germany). But they may not immediately seek medical attention. At the end of two weeks a certain number will have done so, and, for the first time, been identified as covid-infected. Maybe a couple of dozen will be hospitalized, and a week later a few will be dead.
These are tiny numbers in the overall picture, and will hardly register. But: all 800 will have had encounters, met friends and families, been to bars and supermarkets. Many will recover without medical assistance — but will still pass the virus on to others. In total maybe a few thousand new people have been infected, and they will start showing mild symptoms five or six days later, starting the new cycle. The number of new corona-victims will still be comparatively small, and the ones that die will still not turn the death stats around, upwards. But now we have thousands to spread the virus even further. And on it goes, until you have hundreds of thousands of new cases, and thousands of deaths.
So it takes roughly a week for first symptoms to present, two weeks, on average, for the infection to register, and further weeks for first deaths to occur. And it takes a few more weeks for the surge to become noticeable in the statistics. You should actually look at each infection surge, then go back four to six weeks, and check what was going on then. Whatever it was, there is a good chance it was at least partially responsible for the surge.
The orange section on the left of the graph is very roughly the situation today: the infections (blue) are climbing at an alarming rate, while the death rate (red) is still sinking, after many weeks of caution and lockdown. I am predicting that things will change in the coming weeks (green section).
The deaths will start rising again, while the infection rates may (hopefully) have started to decline. The death numbers rise and fall in lock step with the those of the infections, only with an eight to ten weeks time lag.
So I am predicting that the effects of opening society in the US on Memorial Day (May 31), with the bar and home parties, the gatherings, political conventions and rallies that followed, as well as the abandoning of masks, will become fully visible in the course of July and early August. Especially in states like Arizona, Texas and Florida which reopened early and now are recording runaway infection rates. The death rates have still to catch up. After that the surges caused by the Tulsa and the Phoenix megachurch rallies (can this be good?). Infection and then the death rates will spiral.
I sincerely hope I am wrong.
Addendum:
09 July 2020: Today we see first reports of an infection surge in Tulsa, where Trump held his rally on June 20, two and a half weeks ago. Not all of the 6,500 people that attended the rally were from Tulsa. A large number came from other towns and states — and returned home after the rally. The corresponding numbers are hard to track.
