Lecture of poliomyelitis

2021-03-23 12:00 AM

The disease often spreads, sometimes translated into small groups such as kindergartens, kindergartens, and junior high schools

Define

Polio is an acute infectious disease caused by the polio virus. The disease spreads through the respiratory tract and gastrointestinal tract.

The main clinical features are peripheral soft paralysis, without accompanying sensory disturbances.

Research history

The disease was first described by Jakob van Heine in 1840, then studied by Karl Oskar Medin in 1890, so it is also known as Heine - Medin disease.

Poliovirus was discovered by Landsteiner and Popper in 1909.

In the late 1940s and early 1950s, the team of Dr. John Enders at Children's Hospital Boston - USA successfully cultured Polio virus in human tissue, starting to make Polio and Jonas Salk vaccines. Vaccine was successfully developed in 1955, significantly reducing the incidence of the disease. By 1960 there was a vaccine Sabin (by Albert Sabin).

Epidemiology

In the years 2003-2004, polio epidemic appeared in a number of countries in West and Central Africa.

By the end of 2006, at least over 33 countries had used polio vaccines in more than 350 million children. The polio prevention program has also been strengthened and effective in 6 countries with the epidemic remaining, namely Nigeria, Niger, India, Afghanistan, Egypt and Pakistan. 

Pathogens

Group:

Group IV ((+) ssRNA)

Surname:

Picornaviridae

Like:

Enterovirus

Name:

Poliovirus

Poliovirus is a small globular virus 8-27 nm in diameter, made up of RNA and protein, and has no fat.

Polio virus has 3 different types of antigens and does not cause cross immunization.

Type I: Typically, the strain Brunhilde.

Type II: Typically, the Lansing strain.

Type III: Typically, the Leonoid strain.

In which, type I mainly causes disease in typical people, type II causes hidden disease and type III causes less disease.

Viruses are highly tolerant to external environments: In human feces, they live for a few days to several weeks, in water for up to 14 days. Easy to be destroyed by common disinfectants such as: Chloramin B, H2O2, purple and ultraviolet drugs ... at 60 ° C, the virus is killed in 30 minutes.

Inoculum

Are polio patients. The virus can be found in the throat and in the stool of an infected person before and after the onset can be up to 2 weeks or more.

In addition, carriers of the virus with no clinical symptoms are also an important source of transmission.

Infection

The disease spreads through the respiratory tract in the early stages of the disease (throat virus is isolated).

The disease is spread mainly by the digestive tract: Through hands and tools contaminated with vectors, flies. The virus is excreted in the stool of the patient for a long time (up to several months) and enters the digestive tract (mouth) of the healthy person.

Sense of the body

People with high susceptibility to polio virus.

Common age is children 2-8 years old, especially children 2-4 years old accounts for 60-80%.

Infants and adults can suffer but are less frequent and often atypical.

The disease often spreads, sometimes translated into small groups such as kindergartens, kindergartens, and junior high schools. It is more common in the city than in the countryside and occurs in late spring and early summer every year.

After polio, the patient usually has a stable immunity, rarely getting it again.

Mechanism of pathogenesis and pathology

Mechanism of pathogenesis

From the time it enters the body until it enters the central nervous system causing the typical clinical illness (paralysis), the polio virus must twice enter the bloodstream and be localized in some organs. The process progresses through 3 phases:

Infiltration and proliferation phase in the gastrointestinal tract: The virus enters the body through the pharynx, pharynx in the first 24 hours has reached the lymph nodes around the throat, into the lining of the rectum, the Peyer plaque and proliferates there (possibly stool). virus in the pharyngeal mucus and feces is established during this period).

Visceral stage: From the gastrointestinal mucosa, the virus enters the bloodstream (1st time) then to the internal organs (heart, liver, pancreas, adrenal, respiratory ...). Here they continue to proliferate and cause clinical manifestations of the prostate period.

The stage of invading and proliferating in the central nervous system: the virus from the internal organs enters the bloodstream (2nd time) and into the central nervous system, mainly motor neurons in the anterior spinal horn.

In atypical form (without paralysis), the virus only penetrates the lymph nodes, gastrointestinal mucosa or to the bloodstream without entering the central nervous system, then excreted in the feces.

Pathological anatomical injury 

Lesions are mainly in the anterior spinal horn. In addition, the lateral and posterior horns can also be inflamed, but usually mild and atypical. The cervical and lumbar segments are the most common lesions, followed by the brain stem, motor nuclei, vestibular, reticulum, cerebellum and cranial nerves.

General: Meningeal - spinal cord edema congested, gray matter in the anterior horn of the spinal cord is pink or yellow-gray in color, white matter is congested and there are scattered hemorrhages.

Micro: The earliest damage to nerve cells is the destruction of nissl bodies in the protoplasm, leading to degeneration of the neurons and an inflammatory response around neurons, blood vessels and stroma. At the same time, there is an invasive phenomenon of polymorphonuclear leukocytes, lymphocytes, and macrophages. As a result of neuron degeneration, inflammatory response and cell invasion, atrophy of the anterior spinal horn, fibrosis of the stroma and vascular wall. However, the majority of the lesions are reversed and the nerve functions can also be restored after 1-2 months. Some neurons are irreversibly damaged (clinically indicated by sequelae).

Organs outside the nervous system can also be attacked by viruses such as the respiratory system, heart, liver, kidneys, digestive system, etc. but the lesions are usually mild and heal quickly.

clinical

Divide the clinical form

Asymptomatic form: up to over 90%.

Typical conventional form

Paralytic poliomyelitis accounts for 0.1-2% of the disease.

Spinal cord: Account for 60-70% can be paralyzed.

The practice of the spinal cord: A damage to the practice of the spinal cord is rare but often associated with spinal cord damage

Spinal-medullary body: is a combined damage of the two above bodies, accounting for 15-25% of the paralysis.

Cerebral type: Can be alone or combined with damage to the spinal cord, spinal cord

Mild form (Abortive poliomyelitis)

Account for 4-8%.

Non-paralytic poliomyelitis

Account for 1-5%.

Symptoms study according to the clinical form

Typical conventional form

(Paralytic poliomyelitis)

Incubation period: About 5-35 days, average 6-20 days.

Onset (or prostate stage): 3-7 days with rich manifestations:

Fever: Sudden onset, most mild fever, in some cases 39-40 ° C high for 3-4 days.

Inflammation of the upper respiratory tract: Dry cough, sneezing, runny nose, watery eyes, hoarse voice.

Gastrointestinal disturbances: Vomiting, nausea, apple or loose stools.

Nervous and vegetative disorders: Children sweating a lot, facial expressions at pink time, slow pulse (in contrast to rapid pulse when high fever).

Mental state: Lethargy or struggling, or crying or crying.

Muscle pain and spasticity are very early signs and common. These are very valuable signs for early diagnosis because the sore muscles will develop paralysis, often pain and stiffness in the muscles of the neck, torso and thighs making the child tired, weak muscle strength, muscle tone. decreased, sometimes mild twitching in the muscles that will later become paralyzed. Accompanied by signs of reduction or loss of reflexes (when the abdominal skin reflex up to 80% with paralysis).

Meningeal syndrome: Severe headache (accompanied by vomiting, nausea). Examination of physical signs: Nape (+), Kernig (+), Brudzinski (+). In children under 18 months, you can see bulging bulging or Hoyne sign (+): Let the child lie on his back, use 2 hands of the physician to gently lift the child's shoulders, the baby's head cannot rise.

Cerebrospinal fluid test can show a slight increase in cells, normal or slightly elevated proteins, normal glucose and NaCl.

Full-blown period (or paralysis):

Features of paralysis:

Peripheral paralysis, asymmetry.

Paralysis is not in a certain order.

Paralysis occurs suddenly and quickly, usually appears on the 4th - 7th day of illness, when the temperature has returned to normal or the fever is gone 1-2 days earlier. From the onset of paralysis until paralysis does not progress, within 48-72 hours.

Paralyzed muscles are often weak, muscle tone decreases, loss or decrease in tendon reflexes and skin reflexes, muscles rapidly atrophy. The remarkable point is that in these muscles there are no accompanying sensory disturbances.

Zones of paralysis:

Depending on the location of the lesion, there are:

Spinal cord: Account for 60-70% can be paralyzed.

Damage to the cervix: Paralysis of the neck muscles, shoulders, nape, upper extremities (shoulder muscles) and diaphragm.

Lumbar medullary injury: Paralysis of the lower abdominal muscles and lower extremities.

Lumbar medullary injury: Paralysis of the lower abdominal muscles and lower extremities.

The practice of the spinal cord: Damage to the practice of the spinal cord is rare, but often associated with spinal cord damage. The manifestations of damage to the medulla:

Respiratory disorders: Hiccups, shortness of breath, disturbed breathing.

Circulatory disorders: Pulse irregular or pulmonary, arrhythmia, fluctuation in blood pressure and a tendency to decrease.

Nervous and vegetative disorders: High fever, excessive sweating, cyanosis of the skin.

This is a very severe form, with high mortality (50-90%).

Spinal-medullary body: is a combined damage of the two above bodies, accounting for 15-25% of the paralysis.

Cerebral type: Can be alone or combined with damage to the spinal cord, spinal cord. A simple diffuse encephalopathy is often very difficult to distinguish from encephalitis caused by other viruses. This is a rare form, it progresses long and leaves many sequelae.

Other symptoms: Symptoms of muscle pain: increases with the onset of paralysis, lasts for a few days, then gradually decreases. Accompanying headache relief, more alertness, better sleep and eating, less fatigue.

Test:

Peripheral leukocytes are normal or may increase within a few days, then return to normal.

Cerebrospinal fluid test: Cell increase (usually a few tens to a few hundred leukocytes, but rarely up to 1000 leukocytes / mm3), the highest increase in week 2-3 weeks of disease. Cell formula: Initially mainly polymorphonuclear leukocytes, after a few days the lymphocytes gradually dominate and return to normal from the 4th week of disease. Protein in the cerebrospinal fluid can reach 1-2 g / l, peaks at 3 weeks and returns to normal after 1-2 months. About 10% of cases have normal cerebrospinal fluid. However, increased cell and increased protein were not related to disease severity.

Isolation of the virus: From blood (2-3 days before onset and 1-2 days after onset), from pharyngeal mucus (before onset and 10 days after onset), from feces (before onset and prolonged until recovery).

Diagnostic serum: Complement combination and neutralization reaction.

Recovery period and sequelae:

Early recovery: during the first 6 weeks of illness, the paralyzed muscles recover quickly, reducing and eliminating pain, leaving only a few muscles and muscle groups completely paralyzed. This is because most of the neurons that control paralysis muscles first experience edema and dysfunction, and then recover.

Late recovery: After 6 weeks to 2-3 years, some muscles are paralyzed slowly and not clearly, many muscles are completely paralyzed.

Sequelae: Are irreversible damage after 3 years.

Other clinical forms

Clinical asymptomatic form: Diagnosis is determined based on the isolation of the virus from the patient's stool and the presence of antibodies in the serum.

Mild form (Abortive poliomyelitis): Presented by the symptoms of inflammation of the upper respiratory tract, digestive disorders and some flu-like symptoms (fever, joint pain). Diagnosis must also be based on virus isolation and serological response.

Non-paralytic poliomyelitis: Patient has symptoms of the prostate period (in paralysis), prominent meningeal syndrome and signs of meningeal irritation but no paralysis.

Implementing the quadrants

clinical

High fever, myalgia, peripheral paralysis, asymmetry, sudden occurrence, decreased tendon reflexes and no accompanying sensory disturbances.

Test

Isolation of the virus from blood, pharyngeal mucus, feces according to each disease period. The neutralization or complement fusion reaction with the second antibody titer is higher than that of the first.

Epidemiology

Age is susceptible (2-8 years old) and many children in the same group suffer from it.

Differential diagnosis

Prostate period

Flu and respiratory viral infections caused by other viruses: High fever continuously for 4-7 days, often with cold, more severe poisoning, severe headache, rapid progression within 7-10 days.

Meningitis: Meningitis syndrome appears earlier and more loudly, the cerebrospinal fluid is cloudy, the cells increase very high, mainly neutrophils, high protein, reduced glucose. Peripheral leukocytes increased, mainly N.

Other viral meningitis: Mainly based on rapid disease progression after 1-2 weeks.

Paralysis period

It should be differentiated from multi-rooted - nerve inflammatory syndrome (Gullain - Barre), which is common in adults, with symmetrical paralysis of the extremities, the disease rarely leaves sequelae.

Treatment

Treatment of polio

The principles of treatment

Comprehensive treatment, closely combining symptomatic treatment (anti-inflammatory, analgesic, respiratory resuscitation, circulation ...) with improving the body's resistance.

Actively prevent complications and sequelae, create all conditions for patients to restore function and psychology.

Prostate stage

Immobilize the patient for 1-2 weeks.

If you have a high fever, you need to cool down, prevent seizures with cold compresses or medications (paracetamol, efferangan, aspegic).

Pain relief, sedation: Analgin, aspirin, dimedrol (intramuscular or oral), Valium.

If cerebral edema: Glucose 30% injection, intravenous infusion combined with magiesulfate, diuretics.

Injections of calcium gluconate intramuscularly for 7-10 days.

Paralysis stage

Place the patient in a malformation room position.

Actively resuscitate circulation and respiration if due to severe damage in the medullary body: Lay lying on its side in a drainage position, absorb phlegm, breathe oxygen, breathe artificially. Rehydration water, electrolytes, cardiovascular support (Spartein, Coramin) raise blood pressure (Dopamin ...), anti-edema.

Drugs to restore movement in paralyzed muscles:

Proserin is injected intramuscularly with a solution of 0.05% 0.1-0.2 ml / day for 10-15 days.

Dibasol 1-5 mg / day orally for 20 consecutive days, combined with B vitamins.

Antibiotic superinfection of the respiratory and urinary tract.

Gamma globulin for the first 7-10 days.

Early therapy (from the second week of illness), a few days after the fever is gone, should not be left until the pain goes away because the patient with severe pain often has rapid muscle atrophy.

It is possible to apply the following measures: Paraffin bundles, electrolysis, high frequency electrical impulses ... divided into several times, each time for 10-15 days, lasting for 1-2 years.

Combine physical therapy (massage, local movement ...) with psychotherapy.

Recovery period and sequelae

Actively improve the body's resistance.

Continued therapies and physical therapy. Give the patient gentle exercise, practice of walking and other movements.

If there are sequelae can use orthopedic surgery to intervene.

Treatment of mild polio

Pain relief, sedation, hypothermia.

Treatment of digestive disorders.

Increase nutrition, improve resistance.

Follow up closely to detect paralysis.

Treatment of polio cannot be paralyzed

Mainly sedative, analgesic, anti-edema brain.

Therapy can be used if persistent muscle spasm is observed and monitored for two months.

Prevention

General prevention

During the outbreak, the patient must be isolated for at least 2-4 weeks.

Children with fever, respiratory secretion inflammation, and unexplained digestive disorders should be kept at home and monitored daily.

Persons in contact and in patient care duties must be closely monitored. If there are suspicious symptoms: Signs of meningitis, pain along the spine and neck, hypotonia in some muscles, etc. Cerebrospinal fluid must be tested and isolated.

Consider adenectomy or VA curettage for children in epidemic zones.

For patients with mild form or non-paralysis need to limit movement, avoid pain stimulation until clinical symptoms are gone.

Specific

The inactivated vaccine Salk is a pharmaceutical vaccine made from an indestructible polio virus strain using Formalin. This type is used by injection, so it only produces antibodies that do not cause immunity in the intestine. Currently the Salk vaccine is used only when the oral vaccine is ineffective.

The virulent live vaccine Sabin has many more advantages: It is taken by mouth, causes long-lasting immunity, prevents the invasion of wild viruses (due to the creation of immunity in the intestine), is 90-100% effective, low price.

All children (especially babies from birth to 60 months) get 2 drops of Sabin vaccine once and every year. Thanks to this vaccine, many countries have repelled and eradicated polio.