As reported to ECDC by Belgian authorities, on 2 September 2014, following a human error, 45 litres of concentrated live polio virus solution were released into the environment by the pharmaceutical company, GlaxoSmithKline (GSK), in Rixensart city, Belgium. The liquid was conducted directly to a water-treatment plant (Rosieres) and released after treatment in river Lasne affluent of river Dyle which is affluent of the Escaut/Scheldt river. Belgium’s High Council of Public Health conducted a risk assessment that concluded that the risk of infection for the population exposed to the contaminated water is extremely low due to the high level of dilution and the high vaccination coverage (95%) in Belgium.
ECDC’s assessment is that the accidental release in the environment of large amounts of live polio virus represents a risk to public health if susceptible populations, such as areas with low polio vaccine coverage, are exposed to contaminated waters or mud. Particularly since the Lasne and Dyle rivers are joining the Escaut/Scheldt river which flows in the southwestern part of the Netherlands where various orthodox protestant communities present a lower polio vaccination coverage, before reaching the North Sea.