In the week following the relaxed measures in the Netherlands, from Wednesday 26 January to 1 February 2022, the number of reported positive COVID-19 tests spiked, rising to 530,015 (+45%). This significant increase was observed despite a backlog of over 81,000 positive GGD tests reported to RIVM since 18 January 2022**. More than 1,019,496 people were tested by the Municipal Public Health Services (GGDs), 7% more than in the week before that. This is the highest number of tests in one week since the start of the epidemic. 

The highest number of reported positive tests per 100,000 inhabitants was seen in the age group of 13-17 years old. The biggest increase in reported positive tests in the past week was seen in the age groups of 0-12 and 13-17 years. Compared to other age groups, the number of people aged 60 years and older who tested positive for COVID-19 has continued to be low in recent weeks (Figure 1). 

Figure 1: Number of reported positive tests per 100,000 inhabitants, by age group (20 December 2021 to 30 January 2022).

Hospital admissions and reason for admission

In the past week (24 to 30 January 2022), 1,056 new patients with COVID-19 were admitted to hospital nursing wards (last week: 951, +11%), and 78 of those patients were admitted to ICU (last week: 66, +18%).

Reason for hospital admission of new patients with a SARS-CoV-2 infection

Since 25 January 2022, the NICE records have been expanded to record the reason for hospital admission of new patients with a confirmed SARS-CoV-2 infection who are admitted to nursing wards and to the ICU. This will allow better differentiation between patients admitted due to COVID-19 and patients who tested positive for COVID-19 but were admitted to hospital for another reason. Because this change is very recent, incomplete data is available for the past seven days (admission dates 25-31 January). The NICE Foundation is receiving more data from hospitals every day.

The admission reason for patients with SARS-CoV-2 has been divided into 4 categories.

1. Due to COVID-19: COVID-19 is the reason for the patient’s admission and the patient is treated for that disease.
2. Combination with COVID-19: COVID-19 is one of the reasons for admission: the patient is admitted because COVID-19 has exacerbated a pre-existing health condition, such as diabetes or heart failure. The patient would not have needed to be admitted without COVID-19.
3. Other reason for admission: The reason for admission is not related to COVID-19: The patient is admitted for a different and does not need treatment for the SARS-CoV-2 infection.
4. Unknown: It is not (yet) known whether the reason for admission is related to the SARS-CoV-2 infection.

Figure 2: Admission reason for 548 of the 922 patients with SARS-CoV-2 admitted to nursing wards between 25 and 31 January 2022, as recorded by 0.00 on 1 February 2022.

In the past seven days, 922 patients with a SARS-CoV-2 infection were admitted to hospital in the Netherlands. For 41% of these patients, the reason for hospital admission was not (yet) known; for 548 of the patients with a SARS-CoV-2 infection, the reason for hospital admission was known. COVID-19 was the main reason or one of the relevant reasons for hospital admission in 75% of the patients with known admission reasons (see Figure 2). For 57%, COVID-19 was the main reason for hospital admission. In 18% of admitted patients with a known admission reason, the SARS-CoV-2 infection had exacerbated a pre-existing health condition. Without COVID-19, these vulnerable patients would not have needed to be admitted to hospital. 

In all age groups, COVID-19 was the most common reason or trigger for hospital admission (“Due to COVID-19” + “Combination with COVID-19” : 54% – 88%). In patients aged 40 years and older, COVID-19 was more likely to be the main reason for hospital admission (78% – 88%), compared to patients younger than 40 (54% – 67%). 

Figure 3: Admission reason for 68 of the 73 patients with SARS-CoV-2 admitted to intensive care units between 25 and 31 January 2022, as recorded by 0.00 on 1 February 2022.

In the past seven days, 73 patients with a SARS-CoV-2 infection were admitted to ICU in the Netherlands. For 7% of these patients, the reason for ICU admission was not (yet) known; for 68 of the patients with a SARS-CoV-2 infection, the reason for ICU admission was known. COVID-19 was one of the relevant reasons for ICU admission in 78% of the patients with known admission reasons (see Figure 2). For 65%, COVID-19 was the main reason for ICU admission. In 13% of patients admitted to ICU with a known admission reason, the SARS-CoV-2 infection had exacerbated a pre-existing health condition. Without COVID-19, these vulnerable patients would not have needed to be admitted to ICU. In all age groups, COVID-19 was the most common reason or trigger for ICU admission (“Due to COVID-19” + “Combination with COVID-19” : 60% – 100%). 

In this first week of data collection (ICU admission date 25-31 January 2022), it is not yet possible to show a clear age distribution based on reasons for ICU admission. More and more information will become available from the hospitals over the next few weeks.

Separate care protocol for patients admitted for a different reason 

A separate care protocol applies to patients who have a different reason for admission, but also have a SARS-CoV-2 infection for which they do not require treatment. These patients will receive nursing care in isolation. Nurses, doctors and other hospital staff must wear special protective clothing while caring for these patients and during contact with these patients. 

Reproduction number R

The most recent reproduction number for SARS-CoV-2 (17 January 2022) was 1.20 (1.19 – 1.21)**. That is a stabilisation compared to the week before that (1.19 on 10 January 2022). That means that 100 people who had COVID-19 on 17 January 2022 will collectively infect another 120 new people. 

Measures

Prevent the spread of the virus and help to prevent more hospital admissions by following the current measures, even if you are vaccinated. Get vaccinated if you have not yet done so, and get the booster to refresh your protection.

* Positive tests reported to RIVM between 25 January 2022 at 10:01 and 1 February 2022 at 10:00. The number of GGD tests, hospital admissions and ICU admissions are shown by calendar week.
** Due to a technical malfunction in the data flow as of 18 January, not all reported positive tests and data from the test lanes have been fully transmitted to RIVM at this time. Therefore, the figures on reported positive tests and the number of tests displayed in this update are lower than the actual number of reported positive tests. The reproduction number based on reported infections may temporarily be too low due to the backlog, which will be corrected when the delayed reports have been incorporated.