European Countries report a high Case Positivity Rate during the Second wave of COVID-19
Sai Krishna Muthyanolla
November 26, 2020
The European countries & the USA are currently experiencing a second wave of COVID-19. The number of daily cases being reported in each of these countries is way more than the numbers reported during the peak of the first wave. Along with increased testing, the Case Positivity Rates have also increased.
Few days ago, United Kingdom announced the phasing out of its month long lockdown which was in effect since the beginning of this month. The lockdown was announced as a response to the increase in the number of COVID-19 cases in the country.
Apart from UK, few other European countries have seen an increase in the number of COVID-19 cases being reported over the last month or so. These countries were among those which were the earliest ones to be hit by the COVID-19 pandemic earlier this year. Since then, the situation was brought under control and they are not witnessing a spike in the cases in the past couple of months. This is being considered as a second wave of the COVID-19 pandemic.
Over the past couple of months, while the buzz in USA has been around US presidential elections, there has also been an increase in the number of COVID-19 cases being reported.
In this story, we look at the trends relating to the second wave of COVID-19 infection across Europe & USA and ascertain the possible scenario in context of India.
We have considered the data provided on Our World In Data portal, where the information is collated based on the data provided by authentic & reliable sources of each country.
Number of cases significantly higher in the 2nd wave across Europe & USA
Western European countries were among the first to be hit with a higher number reported cases of COVID-19 outside of China.  Italy breached one thousand cases a day mark ( a high number in the initial days of COVID-19 pandemic) during the first week of March 2020 and peaked to around 5– 6 thousand daily cases by the last week of March 2020. The numbers fell gradually during April and by May, less than 1000 cases a day were reported. A similar trend was observed in other countries like Spain, UK, France and Germany where in significant numbers were reported during the first week of March with the daily numbers peaking during early April, followed by a gradual decline.
Post May, the number of daily cases largely subsided in these countries. The quantum of the numbers differ among these countries but the trends remained the same.
However, by Mid-July, Spain followed by France started to report higher number of daily COVID-19 cases, with the numbers peaking by the end of October & early November, indicating a second wave of COVID-19. The increase in the number of daily cases started comparatively late in UK, Italy & Germany. The number peaked in these countries during early November. The important aspect of the second wave is that  significantly greater number of are reported from each of these countries compared to that of first wave.
For instance, the highest number of cases recorded in Italy, Spain & France during the peak of first wave was around 5-6 thousand daily cases. However, during the second wave, the numbers range between 40-60 thousand daily cases during the peak period i.e. approximately 10 times more daily cases than during the peak period of the first wave.
Russia’s trajectory is different from the other countries. After peaking late than the other countries, the drop has also not been as significant as in the case of others. The second wave is also a gradual increase than the sudden spike observed in the other countries.
Over the past week however, there has been a steady decrease in the number of new daily cases reported from Spain, Italy, France & Germany.
Meanwhile in USA, the number of new daily cases being reported over the past two weeks are consistently over one Lakh. During the first wave of COVID-19, the number of daily cases in the USA peaked around mid-July with 60-70 thousand daily cases. This was after a gradual growth of higher number of cases being reported since the end of March’2020.
The peak was followed by a short period of decline, where in by mid-September around 30-40 thousand daily cases were being reported. Signs of a second wave were observed in early October followed by a gradual increase in the number of cases being reported daily. Since 05 November 2020, USA has recorded more than 1 lakh daily cases and this number is only increasing.  It is yet to be seen if this is the peak-phase for the second wave or if the cases continue to increase.
Increase in Case Positivity despite an increase in the number of tests
The number of daily cases is not the only measure for understanding the spread of COVID-19 infection and the intensity of the 2 wave.  The Case Positivity Rate (CPR) is a parameter which offers further insights about the spread of COVID-19.  It refers to the number of COVID-19 positive cases out of the tests that are conducted. A higher positivity rate generally indicates a higher prevalence of the infection.
The testing data for Spain and France during their peak phase of the first wave of COVID-19 infection is not available and hence limits the comparison between the two waves for these countries. However, what can be understood for both these countries is that the higher number of cases being reported in the second wave  also correlate with  higher CPR during this period.
In UK, Italy & Germany, there is a recent increase in the CPR which coincides with their second wave of COVID-19 though the current CPR is less than the CPR during the peak of the first wave.
The USA has a slightly different trajectory. As seen in the trends for number of new daily cases, USA took a longer time to reach its peak. The CPR during that peak period was less their initial CPR since a greater number of tests were being conducted. However, contrary to the trend in European countries which are also experiencing a second wave, the current CPR in USA is more than the one observed during its peak in terms of number of daily cases.
The case of Russia is similar to the Western European countries where in there is a recent spike in CPR but is still less than the CPR during the first peak. Overall, Russia has a lesser CPR compared to the other countries being discussed in this story, with the CPR ranging between 4%-5%.
This could be due to the fact that the first wave peaks of the European countries were during the initial phases of COVID-19 pandemic where the number of tests conducted was lower.
Over the last many months, the number of daily tests has increased significantly across countries. The CPR has increased with the increase in the testing numbers strengthening the claim about higher prevalence of COVID-19 in the 2 wave. The infection seems to be more widespread now compared to the first wave. Spain & Germany do not release data on the number of tests on a daily basis. However, the updates provided during various intervals indicate an increase in the number of tests and a corresponding increase in CPR.
Among the countries being discussed in the story, there is a decrease in the number of daily tests conducted in the France. During this period, there is also a decrease in the CPR of France.
The testing strategies could vary, with few countries conducting more tests and few others resorting to have a more targeted approach for the tests. Nevertheless, the common trend is that that there is an increase in the number of daily tests when compared to the first wave for all these respective countries.
CPR & Number of cases alone do not reflect the severity
While an increase in the number of cases along with an increasing CPR points to a widespread prevalence of COVID-19, they do not convey the complete picture especially with respect to severity. Fatality rate provides is a better indicator of the severity. One of the important aspects observed during the first wave of COVID-19 infections, especially in the Western European countries like Italy & Spain was the higher Fatality rates.
We would discuss about the same in the second part of this story. Furthermore, we would also look at the trend of COVID-19 infection spread in India and how it is different from the trend in these countries. Through this, we would also discuss the possibility of a second wave in India and its potential spread.
Featured Image: COVID-19 Case Positivity Rate