Poliomyelitis (polio) is a highly contagious infectious viral disease, which mainly affects young children below five years old. It is an acute and communicable disease.
Although approximately 90% of polio infections cause no symptoms at all, affected individuals can exhibit a range of symptoms if the virus enters the blood stream. In about 1% of cases, the virus enters the central nervous system, preferentially infecting and destroying motor neurons, leading to muscle weakness and acute flaccid paralysis. Different types of paralysis may occur, depending on the nerves involved. Spinal polio is the most common form, characterized by asymmetric paralysis that most often involves the legs. Bulbar polio leads to weakness of muscles innervated by cranial nerves. Bulbospinal polio is a combination of bulbar and spinal paralysis.
The cost of treatment for polio would range from P200-P2,600 per day, depending upon the degree of involvement. Polio can only be prevented by immunization.
This disease is caused by three types of poliovirus. Poliovirus is a member of the enterovirus subgroup, family Picornaviridae. Enteroviruses are transient inhabitants of the gastrointestinal tract, and are stable at acid pH. Picornaviruses are small, ether-insensitive viruses with an RNA genome.
There are three poliovirus serotypes (P1, P2, and P3). There is minimal heterotypic immunity between the three serotypes. That is, immunity to one serotype does not produce significant immunity to the other serotypes.The poliovirus is rapidly inactivated by heat, formaldehyde, chlorine, and ultraviolet light.
The polio virus leaves its reservoir, the feces of the person. The portal of exit is the anus. The virus is transmitted through contaminated food and water. Oral-oral transmission by way of an infected person’s saliva may account for some cases. The portal of entry is the mouth. The agent enters, and multiplies in the intestine, from where it can invade the nervous system.
The most important step in eradication of polio is interruption of endemic transmission of poliovirus. Stopping polio transmission has been pursued through a combination of routine immunization, supplementary immunization campaigns and surveillance of possible outbreaks. The four key strategies outlined by the World Health Organization for stopping polio transmission are: 1. High infant immunization coverage with four doses of oral polio vaccine (OPV) in the first year of life in developing and endemic countries, and routine immunization with OPV and/or IPV elsewhere. 2. Organization of “National immunization days” to provide supplementary doses of oral polio vaccine to all children less than five years of age. 3. Active surveillance for wild poliovirus through reporting and laboratory testing of all cases of acute flaccid paralysis among children less than fifteen years of age. 4. Targeted “mop-up” campaigns once wild poliovirus transmission is limited to a specific focal area.
APPLICATION OF DISEASE PREVENTION
• Polio vaccination
• Practice of personal hygiene
• Checking food and water is free of contamination
• Chlorination of the community’s water supply
• Inspection of restaurants and retail food markets
• Proper disposal of human waste
• Proper cooking of food
• Health screening
• Annual Physical Examination
• Drug treatments
• Physical therapy