On 6 September, the Belgium authorities informed the European Commission, the Netherlands, ECDC and WHO about an incident that occurred 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, Belgium.
New! Accidental release of 45 litres of concentrated live polio virus solution into
the environment – Belgium
Opening date: 10 September 2014 Latest update: 11 September 2014
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 estimated viral rejection of
live virus Saukett (Salk) serotype 3 was of 10^13 cell culture infectious dose 50% (CCID50). 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
After being informed by GSK, the High Council of Public Health (HCPH) 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. The risk was estimated higher for the personnel of the water-treatment plant so they
received medical assistance/examination and polio vaccination. In addition, their risk assessment concludes that from the junction
of river Lasne with the river Dyle the dilution of the virus in the river water brings the risk to negligible. As a precaution, a booster
dose of polio vaccine was recommended to persons who have been in contact with the water of river Lasne from 2 September
until the date when the precautionary measures will be lifted.
Measures taken by the local health authorities include the molecular (PCR) testing of environmental samples from river water and
sludge, informing the population through a press release on 5 September and activation of a call centre at the Ministry of Health
for the general public, notification of the general practitioners and relevant local health authorities through a letter sent by HCPH
with recommendations. Relevant corrective measures are to be taken by GSK under the control of public authorities.
On 8 September 2014, the Federal Public Service (FPS) Health, Food Chain Safety and Environment in Belgium confirmed
that samples of mud and water taken from the Rosieres treatment plant, river Lasne and river Dyle, all tested negative for the
presence of polio virus.
Web sources: Belgium PHI on 5 September | Belgium PHI on 7 September | FPS on 8 September | RIVM | Eurosurveillance
The accidental release in the environment of large amounts of live polio virus represents a risk to public health in case susceptible
populations are exposed to contaminated waters or mud. The contamination of the rivers depends upon the effectiveness of the
treatment in the Rosiere treatment plan to prevent viruses from being released. 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.