RIVM has found the Omicron variant in test samples taken in the Netherlands earlier in November. These samples were taken in the GGD test lanes on 19 and 23 November 2021. Saltro, the lab that analysed the tests, submitted the samples when requested by RIVM.
In a special PCR test, the samples showed an abnormality in the spike protein. This raised the concern that the Omicron variant of the coronavirus SARS-CoV-2 might be involved. The samples were sent to RIVM for confirmation. On 29 November, two samples were confirmed as the Omicron variant. It is not yet clear whether these people had also visited southern Africa. RIVM has alerted the Municipal Public Health Services (GGDs) in the regions where the samples were taken. The GGD will notify the people involved and start source and contact tracing.
On 26 November 2021, 624 people returning from South Africa were tested for the coronavirus SARS-CoV-2. The passengers were tested at Schiphol Airport; 61 of them tested positive for COVID-19. In total, the Omicron variant was found in 14 of those people. Laboratory tests identified several different strains of the Omicron variant. This means that the people were very probably infected independently from each other, from different sources and in different locations.
Tracking the spread in the Netherlands
There will be various studies in the near future to monitor the spread of the Omicron variant in the Netherlands. For example, the test samples from people who tested positive after returning from southern Africa will be subjected to further analysis by RIVM. Also, RIVM will be retroactively examining older samples from laboratories that routinely perform the special PCR test. That is the first rapid diagnostic test that shows the abnormality in the spike protein. Finally, RIVM will working closely with 31 Dutch laboratories to monitors the occurrence of coronavirus variants via the National Pathogen Surveillance.
International exchange of information
The spread of the Omicron variant is being monitored closely around the world. Experts are eager to learn more as soon as possible in order. How infectious and virulent is the variant? And how well do the existing vaccines work against this variant? All over the world, experts are in daily contact to answer these questions. For example, experts from RIVM are represented in weekly meetings of the World Health Organisation (WHO) and the European Centre for Disease Control (ECDC), and there is a special European network where signals about the coronavirus and variants are exchanged on a daily basis.
Update next week
The reference laboratories at RIVM and Erasmus MC are working closely with various laboratories and the Municipal Public Health Services to gather more information on the Omicron variant. On Tuesday 7 December, RIVM will post an update on the situation on the website.