Wednesday, June 1, 2011

Polio

Poliomyelitis (infantile paralysis or polio motor before) is an enteroviral infection that manifests in four different forms: inaparenta infection, polio nonparalitica, abortive disease, and paralytic disease. Before the 19th century, polio was sporadic. In the 19th century is seen more frequently and 20 polio epidemic.The prevalence of this disease worldwide has decreased significantly through the introduction of aggressive immunization programs. Eradicating the disease is first priority today for the World Health Organization.
The poliovirus is an RNA virus that is transmitted by fecal-oral route or through ingestion of contaminated water. Three serotypes can cause human infection. Incubation is 5-35 days. Initial viral particles replicate in the nasopharynx and alimentary tract and then invade the lymphoid tissues with secondary hematologic extension. After a period of viremia, the virus is neurotropic and causes destruction of the horn spinal motor neurons previously. Destruction of motor neurons leads to the development of flaccid paralysis with bulbar or spinal distribution.
There are two types of vaccines to prevent polio: the inactivated and the attenuated parenterally administered orally. Inactivated vaccine was first available in the market and managed since 1950.Or major advantage is that it contains inactivated virus and is therefore not associated with the outbreak of polio postvaccination. This vaccine is administered when the individual is age 2 months, 4 months and 6-12 months. Today is included in various combinations of vaccines. Trivalent oral polio vaccine used in 1960. Immunization with this type of vaccine is responsible for lower prevalence of disease worldwide. The advantages of this formula is to induce mucosal immunity and low cost. The disadvantage is the association with paralytic polio after vaccination.
Physical therapy plays an important role in rehabilitation of patients with polio. Patients with muscle paralysis benefit from physical activity schemes and attaching passive splint to prevent stiffness of their joints. Gymnastics therapy helps patients with severe bulbar chest to prevent pulmonary complications, such as atelectaziile.Frequent repositioning of the paralyzed patient to help prevent pressure sores.
There is no specific treatment for polio out special gym that helps survival, change and improve the prognosis of disability.Prevention is the key to treatment of poliomyelitis. The development of effective vaccines in tissue culture of human embryonic kidney cells and monkey are the main achievements.Bulbar paralytic poliomyelitis is associated with the highest rate of complications and a mortality of 60%. Patients with abortive polio or inaparenta recover without sequelae. Among acute poliomyelitis infection shows only 4-8% and 1-2% nonspecific disease cause neurological symptoms. Incidence of paralytic disease increases with young age, advanced age, recent exercise, tonsillectomy, pregnancy and diseases with impaired B lymphocyte acute paralytic polio mortality is 5-10%, but may reach 20-60% in casesbulbar involvement.
Signs and symptomsMost cases of polio occurring in pediatric patients. Cause infection or immunization against poliovirus protection for life. Most patients with polio infections are asymptomatic or have only mild symptoms such as pharyngitis or gastroenteritis. These cases are considered minor or abortive poliomyelitis. Mild symptoms associated with viral load and immune response against virus dissemination. Only 5% of patients have damage to the nervous system different from polio nonparalitica the most severe form of paralytic polio.Polio nonparalitica or preparaliticaProdromal symptoms include headache, generalized, mild, 38-40 C fever, pharyngitis, anorexia, nausea, vomiting and muscle cramps. These symptoms may or may not resolve in 1-2 weeks.Headache and fever occur as nerve damage and the signs and symptoms (irritability, anxiety, grip strength, emotional instability, stiffness of neck and back) and kerning and Brudzinski signs of meningitis. Children mild systemic symptoms than adults.Symptoms develop the paralytic paralytic form.Paralytic polioIncubation of exposure until the neurologic phase but extends you 4-10 days to 4-5 weeks. develop muscle cramps and weakness.Muscle weakness tends to be maximal at 48 hours but may develop over a week. No one should detect the progression of weakness after low temperature for 48 hours. Weakness is asymmetric lower limbs being more affected than higher ones.Muscle tone is flaccid, and then absent reflexes are fast becoming.Occasional transient or persistent fasciculations are frequently observed in patients with paralytic polio. Patients accused paresthesia in the affected limbs without real loss of sensitivity.Paralysis remain for days or weeks before recovering slowly over months or years. What factors favor the development of paralytic disease remains uncertain, but some evidence suggests that physical activity and intramuscular injections during the prodrome may be important factors.Paralytic poliomyelitis with bulbar involvement.Purely bulbar form of poliomyelitis without memrelor weakness occurs in children, especially those whose tonsils and adenoid formations were removed surgically. Bulbar paralysis with spinal injury is more common in adults, affecting more frequently the spinal cord and leading to dysphagia, dysphonia, respiratory failure and vasomotor disturbances. Patients may have signs and symptoms such as cough, slow breathing, cyanosis, restlessness and anxiety.When paralysis of the diaphragm and intercostal muscles develop, patients need respiratory assistance and intensive care due to life-threatening respiratory failure. Bulbar cranial nerve impairment and cause obstruction by excessive mucus direct throat and lung weakness. Loss of vasomotor control with circulatory collapse also contributes to increased mortality.Form polio encephalitisIt is very rare and is manifested by agitation, confusion, stupor and coma. Autonomic dysfunction is common and has a high mortality rate.Postpolio syndromeDiagnosis of this syndrome is made when there is a new history of muscle weakness and atrophy with asymmetrical distribution compatible with previous polio. Slow but progressive weakness occurs decades after the first attack of polio. Develop muscle weakness is already affected and those previously considered unaffected. November symptoms are accompanied by fasciculations or atrophy. Patients report fatigue, muscle and joint pain and cold intolerance.
This syndrome is an infectious origin. It is associated with increased motor dysfunction in neurons that survive. The prognosis is generally good, with slow progression of weakness rarely forcing disability or death. The etiology of the syndrome is unclear. Several mechanisms have been suggested. Development depends on the severity of acute disease than the patient's age. Immunological mechanisms are involved and because the affected muscles were described inflammatory changes.Orthopedic complications result from abnormal skeletal deformation under stress: osteoporosis, fractures, joint instability, osteoarthritis and scoliosis. Neurological complications tend to be caused by skeletal deformities and duration of use of adaptive equipment.
Complications of PolioUrinary tract infections are transient in the acute phase of poliomyelitis. Other infections (atelectasis, pneumonia, pulmonary edema, myocarditis) may also occur. Respiratory failure can result from respiratory muscle paralysis or respiratory obstruction by brain damage or respiratory center nuclei.
Evolution polioBulbar paralytic poliomyelitis is associated with the highest rate of complications and a mortality of 60%. Patients with abortive polio or inaparenta recover without sequelae. Among acute poliomyelitis infection shows only 4-8% and 1-2% nonspecific disease cause neurological symptoms. Incidence of paralytic disease increases with young age, advanced age, recent exercise, tonsillectomy, pregnancy and diseases with impaired B lymphocyte acute paralytic polio mortality is 5-10%, but may reach 20-60% in casesbulbar involvement.

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