Since 28 January 2020, it is mandatory for health professionals to report COVID-19 cases and suspected cases to the Public Health Services. COVID-19 is considered an A-disease, which enables the government to take far-reaching measures to prevent the spread of the disease, such as isolation, mandatory quarantine, mandatory treatment or prohibition of professional practice. Other A-diseases are for instance MERS, SARS, smallpox and polio. However, because of the relatively mild symptoms for the majority of cases and the limited testing capacity at the start of the pandemic, not all suspected cases could be tested. Therefore, since 12 March 2020, only confirmed (tested) cases have to be reported to the Public Health Services (see: https://lci.rivm.nl/richtlijnen/covid-19).
Forty GP practices of the Nivel Primary Care Database regularly take sample swabs from people with influenza-like symptoms. Since 7 February, these swabs are also tested for COVID-19. The aim is to provide a good overview of how the virus is spread over the Netherlands. In week 12 (2020), 11% of the swabs contained the coronavirus. The positive swabs were mainly coming from patients living in the highly affected areas (https://www.nivel.nl/sites/default/files/algemene-content/NIVELsurveillance_2020_wk12b.pdf).
Since the first confirmed case, contact tracing was in place for confirmed cases. Since 12 March 2020, contact tracing is focussed on groups of vulnerable patients. Contract tracing is done to inform contacts of confirmed cases, especially those in high-risk groups, and highlight the importance of maintaining high hygiene standards and staying at home when symptomatic. (see: https://lci.rivm.nl/richtlijnen/covid-19).
As of 1 June 2020, contact tracing will be conducted in case of a positive test.
Due to the combined factors of increasing infection rates and capacity problems, several (10 of the 25) regional public health services have announced limits to contact tracing in the middle of September 2020. These public health services will only call persons living in the same home and those at high risk, and otherwise infected people are asked to inform their contacts themselves. The regional public health service in which the national airport is situated announced that people arriving at the airport in a plane with an infected person are called, but not monitored anymore. If they cannot be reached by phone, they receive an email (https://nos.nl/artikel/2349001-tien-ggd-s-beperken-contactonderzoek.html).
The Dutch government developed an app to help contact tracing in case of an infection. The ‘Coronamelder’ app is working in a few regions (as of 17 August 2020) in a testing phase. Originally, the app was planned for a national launch on 1 September, but the Act that should regulate the legal basis for the app has not yet passed the Senate. A special Act was deemed necessary to prevent the possible misuse of the app and provide options for fines in those cases. This is expected to be the case in the beginning of October. The use of the app is voluntary and infections can be reported anonymously (https://www.tweedekamer.nl/kamerstukken/detail?id=2020Z14921&did=2020D32120).
The national launch of the app took place on 10 October 2020, after endorsement of the special Act for the app in the Senate.
The monitoring of the virus in waste water will be slightly changed and become more accurate. Since November 2020, the Corona dashboard published by the government will report the number of virus particles per 100,000 inhabitants. This could not be done earlier, because it was unknown how many people were connected to the waste water sampling points. The waste water can now be measured without the effect of rain water and the sampling frequency will increase from once a week to twice or even more often.
As of 1 December 2020, the quarantine advice for persons without symptoms has shortened to 5 days. If the corona app or contact tracing revealed a suspected contact, a test can be requested after five days. Until then, the person should remain in quarantine. If the test is negative, the person can go out of quarantine. People without COVID-19 related symptoms, but who have been in contact with an infected person, can be tested as well.