What is polio?
Poliomyelitis is more commonly known as polio. Polio is a disease caused by a virus affecting the spinal cord. As a result of the viral infections plaguing the spinal cord, the muscles fall weak and may even undergo paralysis. Polio generally affects infants and young children. Older people might get infected though, and paralysis is more severe in their cases. The virus thrives in poor hygienic conditions.
The polio virus finds its way inside the human body through the mouth via contaminated hands. Contamination occurs via stool of those who housed the virus inside their bodies. After the polio vaccine was introduced nearly 60 years ago, in 1955, the number of polio cases rapidly declined. However, it is still present in certain parts of the world.
How is Polio Transmitted?
Mostly, polio is spread through the stool of infected people. If hands contaminated with the stool have contact with the mouth of another person, or, if someone consumes food and drink which are contaminated, the virus is transmitted. Some other cases may occur via oral to oral transmission, whereby the saliva of an infected person gets mixed with someone else’s.
When and for how much time is an infected person able to transmit the Polio virus?
The disease being contagious, it is important to know when is the infected person able to transmit the virus to others.
Generally, they are most infectious from 7 to 10 days before and after the symptoms begin appearing. But, basically, the person remains contagious throughout, as long as the virus is present in his throat and faeces. The virus remains in the throat for around 7 days after infection and it is expelled in faeces for three to six weeks.
Symptoms of Polio
Only 5 % of those infected actually have symptoms. (Though, symptoms or not, the infected persons can transmit the virus to others.) Otherwise, the symptoms, which appear around 3 to 35 days after infection, are as follows:
- Muscle weakness
Very rarely do people also experience severe muscle pain and stiffness in the neck and the back. Paralysis occurs in less than 1 % of the cases.
Complications Due To Polio
- Paralysis, mostly affecting the legs.
- Muscles involved in the breathing and swallowing processes might also become paralysed, resulting in death.
Treatment For Polio
No cure has been found yet.
Immunity Against Polio
Three strains of the virus exist; therefore, immunity depends on which type of virus infects the person the second time, though second times are rare.
Two types of vaccines have been developed:
- Trivalent oral polio vaccine (tOPV)
- Inactivated polio vaccine (IPV)
However, tOPV, which would be administered via the mouth, is no longer used.
Prevention of Polio
Apart from vaccination, no other method exists.