The polio virus was found last month in the sewage system of the Utrecht Science Park in Bilthoven, the Health and Youth Care Inspectorate reported. It is a variant that is used for the production of the polio vaccine.
Four organizations are located on the Bilthoven site that are allowed to work with the polio virus. Samples are taken from the sewer every three weeks to check whether the polio virus has entered it.
The inspectorate is investigating to find out where the virus comes from.
Two options
The virus can have ended up directly in the sewer through a drain, or through the toilet by an infected employee. In the first case, there is no danger to public health. The Netherlands has a closed sewage system that ends at purification plants that make the virus harmless.
In the event that an infected employee is the source, there is a risk. They can transmit the polio virus in their own circle to people who have not been vaccinated against polio.
For this reason, sewer systems throughout the Netherlands are checked for the presence of the virus. The inspectorate pays particular attention to sewer systems in the Bible Belt, since relatively many people there do not have themselves vaccinated for religious reasons.
Not first time
The polio virus was also found in the same sewer last year and last spring. The last time it was a weakened strain of the virus used to make the oral polio vaccine. The virus probably entered the sewer by an infected employee.
In 2017, two employees of a vaccine producer in Bilthoven were accidentally exposed to the polio virus. One of them was actually infected.
–