2020-08-02

(polska wersja)

• The number of COVID-19 cases is not decreasing; it is actually growing worldwide

• In successive US states, the number of deaths is rising rapidly

• Some European countries record a significant increase in deaths

• In many European countries, the number of diagnosed cases is growing

For nearly two months, the number of COVID-19 cases in the world has been continuously growing. According to WHO data, a quarter of a million diagnosed infections have been registered in the last 24 hours and almost 7,000 people died.

One of the countries where the epidemic is accelerating most is the USA. The plot below clearly shows how the number of deaths is growing for selected states:

The plot above shows the death rate since the day of the 10th dead person for the states where the death rate dynamics are currently highest (a > 0.0075 - measure of the regression rate for the last 10 days): Alabama, Arizona, Arkansas, Florida, Idaho, South Carolina, Tennessee, Texas and Utah. For comparison, the curves for the state of New York and Lombardy were added to the plot to illustrate the number of deaths in the most affected areas of the world where the epidemic seems to be coming to an end. For these states the death rate increased. It is well illustrated by the parameter a, which quantifies the death rate - the greater the number, the greater the death rate:

Also in this plot the curve for the state of New York was added. Since the beginning of the epidemic it has been continuously falling down (the characteristic, ellipsoidal bubble is a single jump in the number of deaths, resulting from the correction of statistics). For the other states, the curves were falling down for about the first two months. In the course of the following month, the rate of fall has clearly slowed down, and in some cases it even stopped. Over the last month it started to rise significantly.

A similar course of the COVID-19 epidemic can be observed in other countries, e.g. Israel and the Czech Republic, where not long ago the end of the epidemic was celebrated:

As can be seen in the plots above, the number of deaths caused by COVID-19 in Israel has been increasing for more than a month, and in the Czech Republic for three weeks. For both plots the curves showing the situation in Poland was added, where the rate of increase of deaths is still slowing down, although noticeably slower last weeks. The same is happening in most European countries:

The plot above shows the change of parameter a for a 10-day regression for Poland comparing to the average value of this parameter (black stared-line) calculated for selected European countries where the epidemic is at a similar or more advanced stage than in Poland: Belgium, Czech Republic, Denmark, Germany, Finland, Spain, France, Norway, Italy, Portugal, UK, Sweden, Ireland, Switzerland and Austria.

It must be mentioned that the dynamics of the number of deaths describes the state of the epidemic with a roughly two-week delay. Currently in many countries, not only in Poland, there is a noticeable increase of the number of diagnosed infections and active cases:

see e.g. Belgium:

France:

Slovakia:

or Japan:

The increase, in many countries, have so far not been accompanied by a clear change in the death rate. This is most likely due to the increasingly effective detection of infected people and contact tracking, which makes it possible to diagnose more cases among the infected than at the beginning of the year, and more effective protection of vulnerable people - statistics in many countries show that a large proportion of the diagnosed and severe cases are young people. However, if this rate of infection will continue growing, SARS-CoV-2 will easily reach the elderly and the ones burdened with other diseases, for whom COVID-19 fatality is several orders of magnitude higher.

A higher number of infections is also a higher number of so-called superspreaders, person who infect many other people in particular, and superspreading events, during which a large number of people are infected. When this is compounded by factors resulting from the fall months, when generally more people fall ill and thus more easily infectious and more often alienate others, and when weather conditions and shorter days make it easier to transmit the virus, we can expect a further increase in the epidemic dynamics in Europe, including more deaths.

Given that there is virtually no chance of mass vaccination the coming fall and that there are tens of thousands of deaths between us and the achievement of population immunity, European communities will have to return to effective social distancing, which is the only way available today to mitigate the epidemic and to reduce the number of deaths and severely ill people. May social empathy, solidarity, and responsibility suffice.