Numbers presented in charts
The two charts below show the number of reported positive tests per 100,000 inhabitants per week (tab one). The figures are presented by age and age group (see other tab). It is also possible to compare the reported positive tests for the different age groups. The figure based on age groups can be used to compare different age groups, such as reported positive tests in children compared to adults.
The figure below shows the data from 6 January 2021 on. The chart shows the percentage of people who tested positive for COVID-19 for each age group, as a proportion of all the confirmed cases reported to the GGD. The corresponding percentages are also displayed.
Children aged 0 to 17 years old comprise 20.7% of the population. The chart shows that they represent a lower percentage of the people who tested positive for COVID-19.
Influence of changed testing policy
Since January 2021, all children can be tested if they have symptoms.
The figures below show the number of COVID-19 tests taken and the percentage of positive test results per age category. The total number of tests performed in the GGD test lanes per 100,000 inhabitants is divided into the number of negative tests (red column) and the number of positive tests (blue column). The green line shows the percentage of positive tests.
From 8 August on, testing decreased among children and adults. After 23 August, the number of tests increased again among children aged 4-11 and 12-17 years and remained the same among children aged 0-3 years and among adults (18≥). The percentage of positive tests decreased among children of all ages and among adults.
As of 1 July 2021, the Municipal Public Health Services (GGDs) also test people for travelling abroad. These test results are not included in the figures below.
Employees working in schools and childcare facilities
Employees working in schools were tested less often during the summer holidays. A person is considered a school employee if they worked on location in the past two weeks.
From 2 August to 12 September 2021, over 20,845 people working in education or childcare were tested. 7.4% of those tests were positive. This percentage is lower than the total of 11.7% of the over 600,000 thousand adults tested in the test lanes in the same period.
During the past week (6-12 September 2021), 8,504 people working in education or childcare were tested. 5.9% of those tests were positive. This percentage is lower than the total of 9.1% of the 113,891 adults tested in the test lanes in the past week.
If we look at all hospital admissions reported by the NICE Foundation in 2020, 0.4% were younger than 4 years old. 0.1% were aged 4-11 years and 0.2% were aged 12-17 years. The vast majority (99.3%) of all people admitted to hospital with COVID-19 were aged 18 years or older.
The same pattern can be observed in 2021 (1 January to 12 September). The percentage of children and adolescents admitted to hospital has not changed over time.
Mainly spread within the same age group
For many people who have COVID-19, it is also possible to trace which other person with COVID-19 is a probable source of the infection. The figure below shows that people mainly infect others around the same age. Infection between parents and children of all ages occurs somewhat less frequently.
The data has been updated to September 2021 and displays 541,789 linked pairs of infected people. It is clear that people in the age group of 15-19 years and older are more likely to be a source of infection than children in the age groups of 0-4, 5-9 and 10-14 years.
Infected contacts according to the age of the source
The Municipal Public Health Services (GGDs) do source and contact tracing. They monitor and test the contacts of the source person and investigate who else may have been infected. The first figure shows how many people in a particular age group were reported as the most likely source of infection. The second figure shows the percentage (%) in a particular age group reported as the most likely source of infection. Both figures display the data per week.
Number of infected contacts according to the age of the sourceSkip chart and go to datatable
Figure 1: The absolute numbers of people (in source and contact tracing) who tested positive for SARS-CoV-2 and infected another person, per age group, per week*.
Explanatory notes to figure 1
Since 5 July 2021, the number of sources increased among all age groups with the exception of children aged 0 to 3 years. This age group is rarely a source of infection. The numbers in this group remain fairly constant and are low. As children grow older, they are more likely to become a source. Compared to adults, children are still less likely to be a source of infection. Since 26 July 2021, the number of sources decreased among all age groups.
Percentage of infected contacts according to the age of the sourceSkip chart and go to datatable
Figure 2: The percentages of people (in source and contact tracing) who tested positive for SARS-CoV-2 and infected another person, per age group, per week*.
Explanatory notes to figure 2
The figure above shows that adults (>18) represent a significant majority as the most likely source of infection. The percentage of children as a source of infection decreases as the age of the children decreases. Children aged 0 to 3 years represent the lowest percentage.
* These figures only show data from source and contact tracing in which the source is known or mentioned. It has not always been possible to conduct comprehensive source and contact tracing. That is why the data is less comprehensive in some periods, such as from March 2021 on. Comprehensive source and contact tracing resumed in mid-May 2021.
Infected children in GP practices
There are around 40 GP practices in the Netherlands that keep track of how many patients visit the practice with flu-like symptoms. These are the Nivel monitoring stations. Using a cotton swab, a smear is taken from the nose and throat of some of these patients; the resulting culture is examined in the laboratory to detect viruses, including the coronavirus SARS-CoV-2. A COVID-19 infection was detected in 8 of the 322 patients under the age of 18 who were tested (2.5%). Of the 1,474 adults who were tested, 125 tested positive (8.5%). This is based on data from February 2020 to 13 September 2021.