Dutch COVID-19 data: worrying, and still too positive?

In the first weeks of September, before the pandemic took a faster track in The Netherlands, the country reported similar numbers of new corona cases as Italy. At the same time, Italy’s death toll in that period was much higher. Was Italy not testing enough? That could have explained the difference. Italy would simply miss many cases, and the true ratio of deaths over cases would be similar for both countries.

It is actually the other way around. On average, Italy tests 3 times more than the Netherlands. It is the Netherlands, with its much higher positivity rate, which would miss many cases. This became painfully visible from September 20 onwards: the Dutch number of infections grew much faster than the Italian one. Of course the death toll always lags behind the number of those fallen ill. But even until now, the daily number of deaths in the Netherlands remains systematically lower than in Italy, as the graph below shows.

We signaled this for the first time on September 25*. As it so happens, RIVM, the Dutch institute for Public Health and Environment, corrected its COVID-19 mortality data on September 26. That day, it included 21 people who all had died of the virus between April and June, and who had never been taken into account. In the Netherlands, there is no obligation to report corona deaths. It shows in the data: deaths are underreported.

Another remarkable difference between the 2 countries concerns hospitalization. The total number of corona patients in hospitals is in Italy 3 times higher. Over the four weeks period considered, nearly twice as many people were hospitalized in Italy, while it had 25% less new cases.

Could it be that the Netherlands also underreport hospitalizations? Could it be that they have higher thresholds for hospitalizing people? Perhaps (twice). A comparison with other European countries suggests in any case that this time Italy is the odd one out. Whereas the Netherlands seems to follow the same trend as Austria, Switzerland, Belgium and the UK, Italy has a much higher ratio of hospitalizations over new cases.

Meanwhile, the Netherlands announced stricter corona rules, like drastically limiting the number of social contacts per individual. On September 30, as one of the last countries in Europe, the government strongly recommended its citizens to wear face masks in public spaces. The country needs to buckle up. Not only is the number of infected people rapidly rising, but all data suggest that their hospitalizations and deaths will even grow faster.