Whooping cough: photos, symptoms, treatment of pertussis
- Mechanism of pertussis
- Symptoms of pertussis
- Symptoms of atypical pertussis
- Complications of pertussis
- Treatment of pertussis
Pertussis is an acute infectious pathology caused by the parasitization of a specific bacterium in the airways of a person and characterized by bouts of severe dry cough. Cases of this infection are registered everywhere, children are more likely to develop it, especially at the age of 3-6. To date, the incidence of pertussis has been reduced to a minimum, thanks to vaccinations introduced into the mandatory vaccination calendar for humans in most countries of the world.
The development of pertussis is caused by a bacterium - Bordetella pertussis, which has a rod-shaped shape, small in size. This bacterium does not form spores and capsule, therefore it is unstable in the external environment and dies in it for several hours. The main feature of the bacterium pertussis causative agent is the development of a number of biologically active substances that determine the characteristic course of the disease:
- Pertussis toxin (lymphocytosis stimulating factor) plays a major role in the development of paroxysmal cough.
- Agglutinogenes are specific compounds on the surface of a bacterial cell that promote its adhesion (attachment) to the mucosa of the respiratory tract.
- Adenylate cyclase toxin - blocks a number of enzymatic systems of epithelial cells of the respiratory system, this compound determines the virulence (ability to lead to the development of the disease) of pertussis pertussis subspecies.
- Tracheal cytotoxin - a specific protein compound, which leads to the destruction of the epithelial cells of the trachea and bronchi with their subsequent sluschivaniem.
- Hemolysin - a bacterial toxin that can cause the death of red blood cells, takes a major part in the development of an inflammatory reaction in the field of parasitizing pertussis bacteria in the respiratory tract.
- Endotoxin is a lipopolysaccharide, which is released when a bacterial cell dies and causes the development of a general intoxication of the body.
- Histamine-sensitizing factor - a substance that leads to activation of allergic reactions in the development of pertussis infection.
All these substances and compounds determine the pathogenicity (the ability to lead to the development of the disease) causative agent of pertussis.
Pertussis belongs to anthropogenous infections. The main reservoir of the pathogen in nature and the source of infection is the human body. In epidemiological terms, people with an atypical form of infection, with no specific symptoms, are more dangerous, people are not isolated and continue to actively isolate the pathogen into the environment. Bovine pertussis is a highly contagious pathogen, which means its ability to rapidly spread and infect a large number of people. This epidemiological feature is especially likely to cause epidemics in children's organized groups (kindergarten, school). The index of contagiousness of bordetella reaches 75-100% - that is, if there is a source of infection, the contact person (under condition of lack of immunity) falls ill in 100% of cases. The incidence of pertussis is higher in childhood (3-6 years), with autumn-winter seasonality and a periodic increase in the incidence rate with a periodicity of 2-4 years. The path of transmission of airborne infection - the bacterium is released from a sick person or bacterial carrier (an infected person, without clinical manifestations of whooping cough) into the environment during a cough with the smallest droplets of sputum, which are suspended in air for a certain time (up to several hours). When this air is inhaled, the bordetelles enter the respiratory tract of a healthy person and lead to infection.
Mechanism of pertussis
The entrance gates (the place of entry into the body) of the infection is the mucosa of the upper respiratory tract. Bacteria attach to epitheliocytes (superficial cells of the mucous membrane) and later on the bronchi descend into the lower parts of the respiratory tract, where they multiply with the release of toxins and products of vital activity. The main factor in the pathogenesis of the infectious process and disease is exogenous pertussis toxin, which causes the development of a number of reactions in the body:
- Increase in systemic arterial pressure due to spasm of arteries and vessels of the microcirculatory bed.
- Inhibition of the functional activity of the immune system (secondary immunodeficiency) - toxins of pertussis bacteria primarily depress the cellular link of immunity (T-lymphocytes).
- The constant irritation of the nerve endings of the mucosa of the respiratory tract, which is the primary link of the cough reflex - this irritation leads to the formation in the cough center of the medulla oblonga of a stable dominant stimulus center that causes the development of a characteristic cough.
The main feature of the pathogenesis of whooping cough is the development of the dominant focus of excitation in the cough center, which is characterized by such signs:
- Summation - the development of cough when exposed to the mucosa of the respiratory tract, even minor irritants (dry air).
- The response of the cough center to irritants that are not specific - a coughing attack can develop as a result of exposure to loud sound, tactile or painful skin irritation;
- Irradiation (spread) of the nerve impulse to the neighboring centers of the brain is vasomotor (increased arterial pressure), vomiting (development of vomiting) and skeletal (the appearance of convulsions) center at the height of a coughing fit.
- Persistence of excitation - the preservation of the focus in the cough center after the release of the organism from pertussis bacteria.
- Inertness - the formed hearth can periodically disappear (thus there are no coughing attacks) with the subsequent renewal.
- The possibility of a transition to a state of parabiosis - a transient excitation in the cough center leads to an end to the formation of impulses in the respiratory center, which explains the cases of respiratory arrest in children at the height of a coughing fit.
The pathogenesis of whooping cough, associated primarily with the impact of pertussis toxin on the human body, determines the clinical manifestations of the disease.
Symptoms of pertussis
Depending on the presence and severity of characteristic symptoms, a typical and atypical form of pertussis is distinguished. For the clinical course of whooping cough is characterized by the presence of periods that differ in their manifestations. These include:
- Incubation period.
- The preconditioned period.
- Period of seizures of a convulsive cough.
- The period of the reverse development of symptoms.
- The period of convalescence (recovery).
The incubation period
This is the time period from the moment of infection of a person with whooping cough, until the appearance of the first symptoms of the disease. Its duration in this case is from 3 to 14 days (an average of about a week). In the incubation period, there is practically no symptomatology of the disease, a person feels normal and does not make any complaints.
The preconditioned period
The main symptom of this period of whooping cough is the appearance and gradual increase of dry cough, against the background of normal body temperature and the absence of signs of general intoxication and other phenomena accompanying acute respiratory disease (runny nose, nasal discharge, sore throat). In the pre-convulsive period, people rarely seek medical help, but attempts to symptomatically treat dry cough with expectorants or mucolytics do not work. The duration of this period is 3-14 days.
Period of paroxysmal convulsive cough
This is the clinical and pathogenetic height of the disease, in which a dominant focus of excitation is formed in the cough center of the medulla oblongata. The main manifestation of this period is the development of an attack of cough that has several main characteristic features:
- A reprise is a condition at the height of a coughing attack, characterized by a series of several coughing jerks on exhalation followed by a wheezing breath. Reprises are a characteristic symptom that indicates the development of whooping cough.
- Deviations of a large amount of viscous transparent sputum at the end of an attack of cough. Sometimes the fit of a convulsive cough ends with vomiting (the result of irradiation of the focus of excitation to the emetic center of the medulla oblongata).
- The development of an attack is usually preceded by an aura that is accompanied by a feeling of anxiety, fear, sneezing or a sore throat.
- During a fit of coughing, a person has a characteristic appearance - reddening of the face with its subsequent cyanosis (bluish color due to worsening of the outflow of venous blood), swelling of the jugular veins, protrusion of the tongue during a cough throughout its length, the tip of the tongue at the same time rising up.
- Tear or ulcers of the tongue bridle are characteristic only for whooping cough (pathognomonic) symptom.
The duration of a coughing attack with pertussis is 2-4 minutes, as the pathology develops, the duration of the attack can be longer. During the interstitial period, a person's face becomes puffy, due to the swelling of his tissues, the skin becomes pale with cyanosis around the mouth. On sclera can develop small hemorrhages in the form of red spots. The duration of the convulsive paroxysmal cough is from 2-3 to 6-8 weeks, depending on the severity of whooping cough. The number and duration of seizures of convulsive cough increase in severe course of pathology to 25-30 times a day.
Period of inverse development of whooping cough
This period is also called early convalescence (recovery). It lasts from 2 to 6 weeks. At the same time, the frequency and duration of attacks of a convulsive cough decrease. The attack itself proceeds more easily, and the general condition and well-being of a person also improves.
The period of convalescence (recovery)
This is the longest period in the clinical course of whooping cough, which lasts from 2 months to 6 months. At this time, there is practically no coughing, but it is possible to periodically recuperate seizures of a convulsive cough, due to the very center of excitation in the cough center of the medulla oblongata.
Symptoms of atypical pertussis
Atypical form of pertussis is characterized by nonspecific symptoms of the disease or its absence. Depending on this, several types of atypical pertussis form are distinguished:
- Abortive appearance - the period of attacks of a convulsive cough is not long, on average, after a week passes into the period of early convalescence.
- Shabby form - throughout the disease there is a dry violent cough, but the development of convulsive seizures is absent.
- Asymptomatic form - characterized by complete absence or minimal development of cough during the course of all periods of whooping cough.
- Transient bacteriocarrier - entering the upper respiratory tract of bacteria without developing the disease and their subsequent destruction through the immune system.
Pertussis is diagnosed only on the basis of a positive result of a specific study, which includes:
- Bacteriological study of the method of seeding the material on a nutrient medium followed by growing and identification of the pathogen.
- Serological diagnosis based on the determination of the increase in titer of antibodies to pertussis bacteria by the agglutination test (RA) or by enzyme immunoassay (ELISA).
To determine the structural changes and the presence of hypoxia (insufficient intake of oxygen into the blood and body tissues), additional instrumental and laboratory research methods are used:
- Radiography of the lungs or their computed tomography.
- Determination of the oxygen saturation of the blood (determination of the presence of hypoxia).
- Common blood and urine tests.
- Blood chemistry.
Complications of pertussis
Pertussis is pathology with severe course and development of a number of specific and nonspecific complications, which often develop in severe form of pathology with frequent and prolonged attacks of convulsive cough. To the specific, directly related to the pathogenesis of whooping cough, the complications include:
- Emphysema of the lungs is characterized by stretching of alveoli due to cough and their increased airiness.
- Emphysema of the mediastinum or subcutaneous tissue in the chest area is the result of the rupture of the airway segment with the accumulation of air in the tissues.
- Severe respiratory failure with a delay of up to 30 seconds or a stop (apnea) for a period of more than 30 seconds.
- Bleeding from the nose, bleeding in the skin of the face and head, sclera of the eyes, brain and spinal cord - can develop due to a violation of outflow of blood from the upper half of the body during an attack of convulsive cough.
- Hernias of the anterior wall of the abdomen (umbilical, inguinal hernia) or prolapse of the rectum, associated with increased intra-abdominal pressure during coughing.
Nonspecific complications of pertussis develop due to the attachment of secondary bacterial infection against the background of a decrease in the functional activity of the immune system. In this case, pneumonia (pneumonia), bronchitis , tracheitis, angina , lymphadenitis (infection in the lymph nodes) or otitis media (inflammation of the middle ear) can develop. Residual (residual effects) in the form of chronic bronchitis or pneumonia, various speech disorders can also remain without complications, children may develop enuresis (night incontinence), visual and hearing impairments, paralysis of certain muscle groups.
Treatment of pertussis
In severe and moderately severe course of the disease, treatment of whooping cough is carried out only in the conditions of a medical hospital, in which it is possible to ensure a minimal impact of various factors provoking the development of an attack of convulsive cough. Also, children from organized groups are subject to hospitalization to prevent the spread of infection. Pertussis therapy includes several mandatory groups of therapeutic measures - a gentle regimen, etiotropic therapy, pathogenetic and symptomatic therapy.
Gentle mode and general activities
During treatment, there are restrictions on the effects on the body of factors that can trigger an attack of convulsive cough - noise, sharp sounds, dry air, emotional stress. Also common recommendations include a diet rich in proteins, carbohydrates and vitamins. Admission of fatty foods is not recommended. It is necessary to keep the relative humidity in the room at a level of 60%.
This therapy is aimed at destroying the causative agent of whooping cough, for which from the first days after the diagnosis, antibiotics of the macrolide group (azithromycin, roxithromycin) or semisynthetic penicillins ( amoxicillin ) are prescribed. The course of antibiotic therapy is about 7-10 days. In the case of a severe course of the disease with frequent coughing and vomiting, antibiotics are injected into the body parenterally - intramuscularly or intravenously in the form of injections.
The main group of medical measures that are conducted to reduce the intensity of the focus of excitation in the cough center of the medulla oblongata. The drugs of the group of neuroleptics (aminazine) and anticonvulsants (seduxen, phenobarbital) are used in the age-related dosages. In addition, antitussive drugs of the group (pertussin, paxeladin), antispasmodics (no-shpa) are used. Pathogenetic therapy includes dehydration (elimination of fluid from the body) to reduce swelling (furosemide).
This additional treatment, which reduces the severity of the main manifestations of pathology. It includes sucking off mucus from the upper respiratory tract, aerosolotherapy, breathing in moistened air, oxygen therapy (breathing air, saturated moistened oxygen). For the prevention of secondary bacterial infection, immunomodulators (metacil, sodium nucleate, eleutherococcus) are used.
The ingestion of pertussis bacterial antigens into the body causes the formation of persistent immunity (subsequent immunity to repeated infection). Therefore, to prevent disease in almost all countries, mandatory vaccination against whooping cough (introduction of bacterial wall antigens into the body, to cause the formation of immunity). A vaccination against whooping cough is performed several times in life, gives a high result in respect of immunity to infection. Even in the case of the development of the infectious process, in vaccinated people the disease proceeds in a mild form without the development of coughing attacks.
The relevance of pertussis remains significant for today, which is associated with its severe course, a periodic rise in the incidence rate in 2-4 years, and the predominant lesion of children aged 3-6 years.