Polio and Polio Virus
Polio is a disease caused by Polio virus. It is also called as poliomyelitis or infantile paralysis. In 20th century it was dreaded childhood disease in United States. In 1955 Polio vaccine was introduced. The polio immunization programme worldwide is run by UNICEF, World health organization and rotary International with technical support from the United States center for disease control and prevention. Besides normal immunization, in India pulse polio programme is conducted twice a year.
In 20th century polio was wide spread in United States. Polio vaccination was done extensively because of which USA and other western countries are free of poliomyelitis. Some African and south Asian countries are still working on Polio eradication program.
Polio virus only affects humans and it is more common in summer months. This virus cannot be destroyed by heat, formaldehyde or ultra violet rays. Once the person is affected with the virus, it can easily transmit to the surrounding people, mainly to children and adults as well. It is mainly transmitted by Oral-fecal rout. After the polio virus transmission person does not show symptoms immediately, it takes 7-10 days. The transmitted virus resides in the intestinal tract and mucus in the nose and throat.
Polio can spread with one of the way from following -
- Eating or drinking food / water from sewage contaminated water.
- Getting in contact with the person who is already contaminated with polio virus.
Once the person is infected by virus, it begins to multiply within the cell membrane. Almost 90% of people who are affected do not show any symptoms. Minor symptoms include - fever, sour throat, nausea, vomiting, abdominal pain, constipation etc. people with minor symptoms have no paralysis, these symptoms last for 2-3 days. And recovery is complete.
About 1-2% infected people develop meningitis, which is recovered within 2-10 days. 1% cases result in paralytic polio with symptoms such as fever, muscle ache, loss of reflexes. Paralysis of leg is common in children under the age of five.
Polio is spread with oral – fecal rout. So, first and foremost prevention is to have public sanitation and careful personal hygiene. Polio vaccine is the major preventive step in Polio eradication program.
Oral Polio Vaccine is highly effective and inexpensive. In India vaccination was started in 1978. Vaccination is given to children below age of 5 years.
Children get four doses of Polio during the schedule.
- 1st at the age of two months
- 2nd at four month
- 3rd dose when they are 6 to 18 months old
- Last dose at 4 to 6 year