Is your child free from polio? Polio (also called poliomyelitis) is a contagious, historically devastating disease that has plagued humans since ancient times. It is catastrophic for the individual and heartbreaking for the family.
Most polio victims are children under five years of age. A portion of the victims die or become permanently crippled. It is the main cause of childhood paralysis in South-East Asia. But only two drops of polio vaccine can prevent this serious disease.
In order to eliminate polio and create awareness about polio, National Immunisation Day will be observed in Bangladesh today. On this day children over 5 years of age will receive oral polio vaccine.
Polio virus can strike at any age, but affects mainly children under five. The virus enters the body through the mouth and multiplies in the intestine. Initial symptoms are fever, fatigue, headache, vomiting, stiffness in the neck and pain in the limbs.
Once established in the intestines, poliovirus can enter the blood stream and invade the central nervous system — spreading along nerve fibres. As it multiplies, the virus destroys nerve cells (motor neurons) which activate muscles. These nerve cells cannot be regenerated and the affected muscles no longer function. The muscles of the legs are affected more often than the arm muscles. The limb becomes floppy and lifeless – a condition known as acute flaccid paralysis (AFP). More extensive paralysis, involving the trunk and muscles of the thorax and abdomen, can result in quadriplegia. In the most severe cases (bulbar polio), poliovirus attacks the motor neurons of the brain stem — reducing breathing capacity and causing difficulty in swallowing and speaking. Without respiratory support, bulbar polio can result in death.
Amongst those paralysed, 5%-10% die when their breathing muscles become immobilised. Although polio paralysis is the most visible sign of polio infection, fewer than 1% of polio infections ever result in paralysis. Poliovirus can spread widely before cases of paralysis are seen.
As most people infected with poliovirus have no signs of illness, they are never aware they have been infected. After initial infection with poliovirus, the virus is shed intermittently in faeces (excrement) for several weeks. During that time, polio can spread rapidly through the community Poliovirus is spread through person-to-person, fecal-oral contact. Where hygiene and sanitation are poor, young children are especially at risk.
Young children who are not yet toilet-trained are a ready source of transmission, regardless of their environment. Polio can be spread when food or drink is contaminated by faeces. There is also evidence that flies can passively transfer poliovirus from faeces to food.
There is no cure for polio, it can only be prevented through immunisation. Polio vaccine, given multiple times, almost always protects a child for life. Full immunisation will markedly reduce an individual’s risk of developing paralytic polio. Full immunisation will protect most people, however individuals can still contract the disease due to the failure of some individuals to respond to the vaccine.
Dr Abu Sayeed Shimul
Source: The Daily Star, November 29, 2008
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