What is Paralytic Polio?

It is an acute infectious disease caused by poliomyelitis virus, and its lesions are mainly in the motor neurons of the nervous system, especially the gray matter in the anterior horn of the bone marrow. In severe cases, the central nervous system can be involved. More common in fever, sore throat, limb pain. More common in children, and some patients can develop flaccid paralysis, so it is also called polio. Most patients can be cured, and severe cases can die due to difficulty breathing and swallowing. Only a few patients have the sequelae of paralysis.

Chinese name: Polio

Foreign name: poliomyelitis
Department: Department of Infectious Diseases, Neurology

Bone gray matter inflammation

Where polio exists, it is transmitted by individuals in contact with or eating contaminated food and diet. The early symptoms of polio are headache, sore throat and fever. Then there was pain in the neck muscles and back muscles. When the condition is severe, the muscles are weak and may eventually lead to paralysis.

What made the polio virus world famous was the President of the United States Franklin Roosevelt during World War II. After returning from an overseas trip, Roosevelt, who was already an adult, found himself infected with polio virus and became a misnomer "Polio". Roosevelt, then president of a New York bank, fought against polio with amazing perseverance and finally defeated the disease, but he could only sit in a wheelchair for life.

Roosevelt's victory over polio encouraged countless people, and some consortia and individuals donated money for the research of poliovirus. In 1945, human and monkey non-nerve tissue cultures were used to isolate poliovirus, and it could be passaged. Poliomyelitis virus was confirmed as RNA virus in 1953, and inactivated vaccine was successfully developed in 1954. Large-scale vaccination is essential to defeat poliovirus. However, scientists found that this vaccine, due to injection, only produces IgG antibodies in the blood of the human body, while polio is an enterovirus. Children's piles of play allow the virus to enter the digestive tract from the mouth and then be excreted in the feces. Infecting unvaccinated children, scientists have further invented polio sugar pills that can be taken orally, which can produce IgA antibodies in the intestine, and even if the virus enters by mouth, it is eliminated in the intestine. Now poliovirus may become The next virus to be wiped out.

Polio epidemiology

Humans are the only natural host for poliovirus. Recessive infections (accounting for more than 99%) and patients with mild paralysis are the main sources of infection. Paralysis is of little significance because of obvious symptoms. Fecal-oral infection is the main mode of transmission of this disease. The virus is excreted from the nasopharyngeal secretions and feces of patients from 3 to 5 days before the onset of disease to 1 week after the onset of disease. Close contact with life and poor health habits can spread it. The population is universally susceptible, and lasting rabbit virulent and type-specific after infection. Babies <4 months have antibodies from the mother, so they rarely develop disease, and the incidence gradually increases after 5 years, and then decreases after 5 years.

The disease is widely distributed throughout the world. The peak of epidemics in temperate regions is from May to October, and it is visible all year round in tropical regions. Due to the application of live attenuated vaccines, the incidence has decreased significantly, but China is still an endemic area. In 1988, the World Health Organization proposed the global eradication of myelitis in 2000, and the action plan for eradication of the disease in 1989. The Chinese government attaches great importance to this and has mobilized the country to do a good job in vaccination and carry out immune boosting measures. The eradication of this disease will be just around the corner.

Polio Pathogenesis and Pathology

The virus enters the body through the oropharynx of the host, and because of its acid resistance, it can survive in gastric juice, and proliferate in intestinal mucosal epithelial cells and local lymphoid tissues, and at the same time expel the virus. At this time, if the body's immune response is strong, the virus can be eliminated It is a recessive infection; otherwise, the virus enters the human blood circulation through the lymph, forming the first viremia, and then spreads to the lymphatic tissues throughout the body to proliferate, causing symptoms such as fever. If the virus does not invade the nervous system, the body's immune system can clear the virus The patient does not show neurological symptoms, which is a frustration type; after the virus has proliferated in large quantities, human blood can form again, forming a second viremia. At this time, the virus can break through the blood-brain barrier and invade the central nervous system, so about 1% of patients have Typical clinical manifestations, in which mild patients have neurological symptoms without paralysis, and severe patients are paralyzed, which is called paralytic.

Virus replication in the nervous system leads to pathological changes, and the speed of replication is an important factor determining its neurotoxicity. The lesions are mainly in the anterior horn of the spinal cord, cerebral medulla, pontine and midbrain, starting with Nissl degeneration of motor neurons, followed by nuclear changes, infiltration of polymorphonuclear cells and monocytes around the cells, and destruction by neurophagic cells. disappear. But not all affected neurons are necrotic, and the damage is reversible. After 3-4 weeks of onset, edema and inflammation subsides, and nerve cell function can gradually recover. High risk factors for paralysis include excessive fatigue, strenuous exercise, intramuscular injection, tonsillectomy, and genetic factors.

Poliomyelitis diagnosis:

1. The incidence is mostly in summer and autumn, and there is a susceptibility to the disease.

2. Laboratory examination: Cerebrospinal fluid shows increased cells and normal sugars and chlorides. Cell protein separation is helpful for diagnosis. Blood poisoning is separated. Virus isolated from nasopharynx and feces is helpful for diagnosis. Separated from blood and cerebrospinal fluid. A virus can confirm the diagnosis. The complement binding test was significantly increased, and the titer of the neutralizing antibody in duplicate serum was 4 times or more, which has diagnostic significance.

3. This disease should be distinguished from infectious polyradiculitis, which is more common in older children, not feverish, and dilatation paralysis gradually appears, ascending, symmetrical, more sensory disorders, and protein in the cerebrospinal fluid Increasing and decreasing cell protein separation phenomenon, paralysis generally recovers quickly, and there are few sequelae.

Poliomyelitis clinical manifestations

The incubation period of this disease is 5 to 14 days, and clinical manifestations of multiple types: recessive infection; frustrated type; non-paralytic type; paralytic type.

1 Poliomyelitis 1, prodromal stage

The main symptoms are fever, loss of appetite, sweating, irritability, and general hypersensitivity; nausea can also be seen. Vomiting, headache, sore throat, constipation, diffuse abdominal pain, rhinitis, cough, throat exudate, diarrhea, etc., last for 1 to 4 days. If the disease does not develop, it is frustrated.

2 Poliomyelitis 2, pre-paralysis

One to six days after the disappearance of the prodromal symptoms, the body temperature rises again, headache, nausea, vomiting are severe, the skin is red, there is a transient bladder sphincter disorder, posterior cervical muscle group, trunk and limb stiffness, burning pain, and often constipation. Physical examination shows: Tripod sign: when the patient sits up, they need to support with two hands on the bed, such as a tripod, to support the body position; Knee test positive, that is, the patient can not touch the knee when the lip is sitting and bending the neck; Head drooping sign, that is, placing the hand under the patient's shoulder and raising his torso, the head of a normal person is parallel to the torso. If the condition ends here, it will be non-paralyzed after 3 to 5 days. If the condition continues to develop, changes in key reflexes usually occur 12 to 24 hours before paralysis. The initial reflexes are shallow reflexes, and deep tendon reflexes are inhibited later. Therefore, early detection of reflex changes has important clinical diagnostic value.

3 Poliomyelitis 3. Paralysis

From the 3rd and 4th days of the pre-paralysis period, most of them appear paralyzed when the body temperature begins to decrease, and gradually increase. When the body temperature returns to normal, the paralysis stops developing without sensory disturbance. Can be divided into the following types:

1. Spinal type This type is most common. Presented as flaccid paralysis, asymmetry, disappearance of tendon reflexes, decreased muscle tone, lower limbs and large muscle groups are more susceptible than upper limbs and small muscle groups, but only single muscle groups may be involved or limbs may be paralyzed, such as involving the neck and back Muscles, diaphragm muscles, intercostal muscles, there are vertical head and sitting difficulties, respiratory movement disorders, paradoxical breathing and other manifestations.

2. The medulla oblongata, also known as the bulbar type, is caused by the violation of the motor nerve nucleus of the cranial nerve and the breathing and circulation centers of the medulla oblongata. This type accounts for 5% to 10% of the paralyzed type. Irregular breathing and apnea occur when the respiratory center is damaged; changes in blood pressure and pulse rate can occur when the vascular motor center is damaged, both of which are fatal lesions. When the cranial nerve is damaged, the corresponding symptoms and signs of neural palsy appear. The facial nerve and the Xth injury to the cranial nerve are more common.

3 This type of brain is rare; it is characterized by high fever, restlessness, convulsions, or lethargic coma, with spastic paralysis of upper motor neurons.

4. The performance of mixed types and above.

4 Poliomyelitis 4. Recovery

Paralysis begins from the distal limbs and lasts for weeks to months. Normal cases can be fully recovered within 8 months, and severe cases require 6 to 18 months or more.

5 Poliomyelitis 5, sequelae

In severe cases, the affected muscles atrophy and nerve function cannot be restored, causing deformities of the affected limbs. Partial paralytic cases develop progressive neuromuscular weakness and pain several decades after infection, and paralysis of the affected limbs becomes worse, known as "post polio muscular atrophy syndrome". The cause is unknown.

Poliomyelitis

Peripheral or central respiratory paralysis can cause aspiration pneumonia, atelectasis, suppurative bronchitis, and respiratory failure to cause severe bleeding; long-term bedridden can cause bedsores and negative balance of nitrogen and calcium, manifested as osteoporosis, urinary tract Stones and renal failure.

Polio treatment

Management principles are to reduce fear, reduce bone deformity, prevent and manage comorbidities, and rehabilitate.

1 Poliomyelitis 1, prodromal and pre-paralysis

1. Bed rest The patient stays in bed for 1 week, and avoids physical activity for at least 2 weeks. When using a bed, use a footboard to make the feet and calves at the correct angle to facilitate functional recovery.

2. For symptomatic treatment, antipyretic analgesics and sedatives can be used to relieve the discomfort and pain of muscle spasms in the whole body; apply hot and humid compresses every 2 to 4 hours for 15 to 30 minutes each; hot water baths are also effective, especially for young children , Synergistic effect with analgesics; slight passive exercise can avoid deformities.

2 Poliomyelitis 2, Paralysis

1. Correct posture When the patient is in bed, the body should be in a straight line, the knees should be slightly bent, the hips and spine can be straightened with a plate or sandbag, and the ankle joints are 90 °. Immediately after the pain disappears, take active and passive exercises to avoid bone deformities.

2, proper nutrition should be given a nutrient-rich diet and a lot of water, such as high temperature or sweat caused by hot compresses, you should add sodium salts. Anorexia can be used to ensure the intake of food and water.

3. Drugs that promote nerve conduction functions, such as dobazole, are administered at a dose of 1 mg for 1 year old, 2 mg for 2 to 3 years old, 3 mg for 4 to 7 years old, 4 mg for 8 to 12 years old, and 5 mg for those over 12 years old, orally once every other day; Drugs that improve muscle tone, such as galantamine, 0.05 ~ 0.1mg / kg daily, intramuscularly, are generally used after the acute phase.

4, bulbar paralysis keep the airway unobstructed: use a low head position (bed feet raised to 20 ° ~ 25 °) to prevent saliva, food, vomit and other people from sucking, avoid gastric tube feeding for the first few days, and use intravenous routes to supplement nutrition; Measure blood pressure twice a day. If there is hypertensive encephalopathy, it should be handled in time. Patients with vocal cord paralysis and respiratory muscle paralysis need tracheotomy, and those with impaired ventilation need mechanical assisted breathing.

3 Polio 3, recovery and sequelae

After the body temperature returns to normal, muscle pain disappears and paralysis stops developing, active functional recovery treatment should be performed, such as massage, acupuncture, active and passive exercise, and other physical therapy measures.

Polio prevention

Vaccinations must be universal, and the following are commonly used:

IPV Poliomyelitis inactivated vaccine IPV

The advantage is safety, it is generally used for immunodeficiency patients and their family members, and can also be used for immunosuppressive therapy; the disadvantages are that the price is expensive, the immune maintenance time is short, and repeated injections are needed, and the intestinal tract cannot produce local immunity .

OPV OPV live attenuated polio vaccine

The advantage is that it is easy to use, and more than 95% of the vaccinators have long-term immunity, and can produce specific antibodies sIgA in the intestine, so that contacts can also get immune effects; but because it is a live virus, it is used for immunodeficiency patients or People who are immunosuppressive can cause paralysis. In China, live attenuated polio vaccines have been made since 1960. One type is a monovalent sugar pill of type III; the other is a mixed polyvalent sugar pill, which is a type I, II, and III mixture. This type of vaccine is commonly used and can be stored at -20 ° C for 2 years and at 4-8 ° C for 5 months. Generally, the first immunization starts from 2 months of age, and is taken 3 times, with an interval of 4 to 6 weeks, and the immunization is strengthened once at the age of 4 years. Do not drink hot water or beverages within 2 hours after taking sugar pills, and do not breastfeed, so as not to affect the effect. Very few children can develop vaccine-associated paralytic polio after use.

Once the patient is found, it should be isolated for at least 40 days from the date of onset. The patient's clothing should be boiled or exposed to sunlight for 2 hours for disinfection. Close contact should be observed continuously for 20 days. Those who have not taken the vaccine can be injected with gamma globulin 0.3 ~ 0.5ml / kg.