Poliomyelitis is an acute viral infection that occurs with a predominant lesion of the gray matter of the brain, which causes the development of paresis and paralysis. Signs of poliomyelitis can be found in children under the age of 7 years, but the risk of contracting it, under certain circumstances, remains for adults.
A bit of history
Polio is characterized by acute infectious damage to the spinal cord and brain stem, resulting in the development of paresis and paralysis, bulbar disorders. Polio disease, the signs of which were known for a very long time, spread widely in the 19th and early 20th centuries. During this period, massive epidemics of this infection were recorded in the countries of America and Europe. The causative agent of poliomyelitis was discovered in 1908 by Vienna by E. Popper and K. Landstein, and the lively inactivated vaccines created by A. Seybin and J. Solk made it possible to significantly reduce the number of cases when signs of poliomyelitis were detected in children by the age of 50 years of the last century.
The positive dynamics in the fight against this infection continues due to active immunization, frequent signs of poliomyelitis persist only in some countries - Pakistan, Afghanistan, Nigeria, India, Syria - while in 1988 their number reached 125. The number of cases during this period decreased from 350 thousand cases (of which 17.5 thousand are fatal) to 406 cases detected in 2013. The countries of Western Europe, Russia and North America today are considered territories free from this disease and signs of poliomyelitis are detected here only as sporadic cases.
Pathogen
Poliomyelitis is a viral disease. The cause of it is the poliovirus, which refers to enteroviruses. Three types of virus are determined (I, II, III). For humans and monkeys, pathogens of types I and III. II can affect some rodents. The virus contains RNA, its size is 12 mkm. It is stable in the environment - in water it can be stored up to 100 days, in milk - up to 3 months, up to 6 months - in the patient’s secretions. Conventional des. funds are ineffective, but the virus is quickly neutralized by autoclaving, boiling, exposure to ultraviolet light. When heated to 50 ° C, the virus dies within 30 minutes. When infected during the incubation period, it can be found in the blood, the first 10 days of the disease in swabs from the pharynx and very rarely in the cerebrospinal fluid.
Transmission mechanism
The source of infection in polio can be both a sick person and an asymptomatic virus carrier (in some cases, carriage can persist for three to five months after recovery). The virus is released into the external environment with feces of the patient and nasopharyngeal mucus. The following transmission routes are relevant for polio:
contact;
airborne droplet;
fecal-oral.
The most common route of transmission is fecal-oral - the virus enters the body through contaminated hands, cutlery, food, and water. Also, mucus is excreted by the patient from the nasopharynx from the 2nd day of illness during the first 2 weeks.
The susceptibility of the virus is 0.2–1%, most of the cases are children under 7 years of age. The peak incidence occurs in summer and autumn.
Risk factors
Factors contributing to the spread of infection include:
lack of hygiene skills of the child;
crowding of the population;
poor sanitary and hygienic conditions, including violation of the sanitary regime in child care facilities;
frequent diseases (more than 4 times a year) in a child;
immunodeficiency states;
low vaccination rates.
Classification
Poliomyelitis is classified by the nature of damage to the nervous system:
non-paralytic forms - occurring without pronounced lesions of the nervous system - meningeal, abortive (visceral), non-apparatus (asymptomatic and represents a virus carrier that can only be determined by laboratory means) forms;
paralytic form.
In turn, the paralytic form is classified according to the location of the lesion. Allocate:
spinal form - characterized by flaccid paralysis of the limbs, trunk, diaphragm, neck;
pontine form - proceeds with complete sludge with partial loss of facial expressions, sagging of the corner of the mouth on half of the face, lagophthalmos;
bulbar - characterized by impaired speech, swallowing, respiratory disorders and cardiac activity;
encephalitis - focal and cerebral symptoms ;
mixed form - pontospinal, bulbospinal, bulbopontospinal.
In the course, there are mild, moderate, severe and subclinical forms.
Incubation period
The incubation period, when the first signs of poliomyelitis are not yet manifested, lasts from 2 to 35 days. Most often, its duration is 10-12 days, depending on the individual characteristics of the child's body. At this time, through the entrance gate (they are the pharynx and digestive tract), the virus enters the lymph nodes of the intestine, where it multiplies. After that, it enters the bloodstream and the stage of viremia begins, during which the infection spreads throughout the body and affects the most vulnerable parts of it. In the case of polio, these are the anterior horns of the spinal cord and myocardial cells.
Symptoms of the meningeal form
Meningeal and abortive forms are nonparalytic forms of poliomyelitis. The first signs of poliomyelitis in children with a meningeal form always appear acutely. The temperature rises to 38–39 ° in a few hours. Symptoms characteristic of a cold appear - coughing, serous or mucous discharge from the nose. When examining the throat, hyperemia is noted, there may be a plaque on the tonsils and palatine arches. At a height of temperature, nausea and vomiting are possible. In the future, the temperature decreases and the condition of the child stabilizes for two to three days.
Then a repeated increase in temperature follows, and the signs of poliomyelitis become more distinct - drowsiness, lethargy, lethargy, headaches, and vomiting appear. Meningeal symptoms appear: a positive Kerning symptom (a patient lying on his back bends his leg in the knee and hip joints at an angle of 90 °, after which, due to muscle tension, it becomes impossible to straighten the knee joint), stiff neck (inability to lie on the back with your chin up to the chest )
Abortive form
Symptoms of polio in children with an abortive form also begin to manifest sharply. Against the background of high temperature (37.5–38 °), malaise, lethargy, and mild headaches are noted. Small catarrhal phenomena appear - cough, runny nose, redness of the throat, there may be abdominal pain, vomiting. In the future, catarrhal tonsillitis, enterocolitis or gastroenteritis may develop. It is the intestinal manifestations that distinguish abortive polio. Signs of the disease in children in this case most often consist of pronounced intestinal toxicosis by the type of dysentery or cholera. Neurological manifestations with this form of poliomyelitis are absent.
Paralytic polio
This form of poliomyelitis is much more severe than the above forms and is much worse treatable. The first neurological signs of poliomyelitis begin to appear on the 4th – 10th day from the moment of contact with the virus, in some cases this period can increase up to 5 weeks.
In the development of the disease, the following stages are distinguished.
Preparative. A rise in temperature to 38.5–39.5 °, headaches, cough, runny nose, diarrhea, nausea, and vomiting is characteristic. On day 2-3, the condition normalizes, but then a new rise in temperature begins to 39 - 40 °. Against her background, severe headaches and muscle pains appear, convulsive muscle twitches that can be noticed even visually, impaired consciousness. This period lasts 4–5 days.
The paralytic stage is characterized by the development of paralysis. They develop suddenly and are expressed in the absence of active movements. Depending on the form, paralysis of the extremities (most often the legs), trunk, neck develop, but sensitivity, as a rule, is not impaired. The duration of the paralytic stage varies from 1 to 2 weeks.
The successful recovery phase is characterized by the restoration of the functions of the paralyzed muscles. At first this process is very intense, but then the pace slows down. This period can last from one to three years.
At the stage of residual effects, the affected muscles atrophy, contractures form, and various deformities of the limbs and trunk develop, which are as widely known as signs of poliomyelitis in children. The photos presented in our review illustrate this stage quite clearly.
Spinal form
It is characterized by an acute onset (the temperature rises to 40 ° and, unlike other forms, has a constant character). The child is sluggish, dynamic, drowsy, but hyper-excitability is also possible (as a rule, its symptoms are more pronounced in very young children), convulsive syndrome. There are spontaneous pains in the lower extremities, aggravated by a change in body position, pain in the spinal and occipital muscles. On examination, symptoms of bronchitis, pharyngitis, rhinitis are revealed. Cerebral symptoms appear, hyperesthesia (increased reaction to various pathogens). When you click on the spine or on the site of the projection of the nerve trunks, a sharp pain syndrome occurs.
For 2-4 days from the onset of the disease, paralysis occurs. With polio, they have the following features:
asymmetry - the lesion is of the type of left arm - right leg;
mosaicism - not all limb muscles are affected;
decrease or absence of tendon reflexes;
decreased muscle tone up to atony, but the sensitivity is not impaired.
The affected limbs are pale, cyanotic, cold to the touch. Pain syndrome leads to the fact that the child is in a forced position, which, in turn, causes early contractures.
Restoration of motor functions begins with 2 weeks of illness, but this process continues for a long time and unevenly. Pronounced tissue trophic disturbances develop, lag in limb growth, joint deformities, bone tissue atrophy. The disease lasts 2-3 years.
Bulbar form
The bulbar form is characterized by an extremely acute onset. The preparative stage is almost absent. Against the background of a sore throat and suddenly rising to high numbers (39-49 °), neurological symptoms occur:
The course of the disease can be complicated by pneumonia, atelectasis, myocarditis. It is also possible the development of gastrointestinal bleeding, intestinal obstruction.
Pontine form
The pontine form occurs due to the defeat of the facial polio virus, abduction, and sometimes trigeminal nerves (V, VI, VII, pairs of cranial nerves). This leads to paralysis of the muscles responsible for facial expressions, and in some cases the masticatory muscles. Clinically, this is expressed in asymmetry of the muscles of the face, smoothness of the nasolabial folds, the absence of horizontal wrinkles on the forehead, ptosis (omission) of the angle of the mouth or eyelid, its incomplete closure. Symptoms become more pronounced when you try to smile, close your eyes or puff out your cheeks.
Treatment
There is no specific treatment for polio. When a patient is diagnosed, they are hospitalized in an infectious diseases hospital where they are provided with physical and mental peace. In the preparative and paralytic periods, painkillers and diuretics are used, according to indications, they give anti-inflammatory drugs or corticosteroids. In case of swallowing dysfunction - feeding through a probe, in case of respiratory failure - mechanical ventilation. During the recovery period, exercise therapy, massage, physiotherapy, vitamins and nootropic drugs, spa treatment are indicated.
Prevention
Polio refers to those diseases that are easier to avoid than to treat. This can be done with vaccination. In Russia, all newborns are vaccinated. Vaccination is carried out in several stages - at 3 and 4.5 months, the baby is inoculated with an inactivated vaccine. At 6, 18, 20 months, the procedure is repeated using a live vaccine. The last vaccination is carried out at 14 years old. And do not skip it, because, despite the fact that it is believed that polio is dangerous only for babies, this is not so, and in the case of a disease, the signs of poliomyelitis in adults are very pronounced and dangerous.
If an ailment is detected, an important element of prevention will be timely isolation of the patient, quarantine and observation of the contact group for 3 weeks, and personal hygiene.
Thus, we examined in sufficient detail what signs of polio exist, and what needs to be done to avoid this serious illness.