Polio is a disease that has been eradicated in Belgium, yet it is still rife in other parts of the world. For as long as the polio virus is in circulation, unvaccinated children, from any country of origin, will run a risk of contracting polio. There is no treatment against polio, vaccination is the only means of prevention.
How is poliovirus transmitted?
The polioviruses that cause polio are transmitted between humans:
- principally by a faecal-oral route: ingesting water or food that is contaminated by faecal matter
- more rarely by saliva or droplet spread transmission (respiratory secretions emitted by coughing or sneezing).
The virus penetrates into the body and multiplies in the throat and the small intestine. In infected people, the virus can spread to the central nervous system where it can cause paralysis (in less than 1% of cases).
DID YOU KNOW? A person can carry the virus without presenting any symptoms: these are called “healthy carriers”. The poliovirus can be present in the stools and saliva of a healthy carrier. The healthy carrier can therefore transmit polio.
Contagiousness and factors that favour transmission of the poliovirus
The poliovirus is mainly transmitted between the patient and their close friends and family. A person who is infected by the polio virus is very contagious:
- 7 to 10 days before symptoms appear
- and 7 to 10 days after symptoms appear.
Transmission is possible for as long as the virus remains in the saliva and in faecal matter.
Polioviruses can survive in the environment for weeks or months depending on different factors such as temperature or humidity levels for example.
Poor hygiene conditions and physical proximity with an infected person or a healthy carrier favour transmission of the poliovirus.