Whooping cough – an infectious disease of the respiratory tract, which is caused by specific bacteria Bordetella pertussis (whooping cough stick, stick Bordet-Zhang), characterized by acute catarrh of the respiratory tract and the attacks of
The causative agent of whooping cough (Bordetella pertussis) is a short rod with rounded ends (0.2-1.2 m), Gram-negative, immobile, well stained with aniline dyes. The antigenically homogeneous. The antigen, which causes the formation of agglutinins (agglutinogen) consists of several components. They are named factors and denoted by numbers from 1 to 14. 7 is a generic factor, Factor 1 contains B. pertussis, 14 – 5.
Pertussis is widespread in the world. Every year about 60 million sick people, of which about 600,000 die. Pertussis occurs in countries where for many years widely held pertussis vaccination. For example, in the United States from 1980 to 1989. It registered 27,826 cases of pertussis, and 12% of them were persons 15 years and older [P. Lange, 1993]. Probably, adult pertussis is more common, but it is not detected, as occurs without the characteristic seizures. In a study of patients with persistent cough lasting at 20-26% serologically detected pertussis infection. The reservoir and source of infection is the only man (patients with typical and atypical forms of whooping cough, as well as healthy bacillicarriers). Especially dangerous in patients with early stage disease (catarrhal period). infections are transmitted by airborne droplets. Upon contact with the patients disease in susceptible individuals develops at up to 90%. Most sick children of preschool age. More than 50% of cases of whooping cough in infants is associated with lack of maternal immunity and possibly lack of transplacental transfer of protective antibodies specific. In countries where the number of vaccinated children is reduced to 30% or below, the level and dynamics of pertussis becomes the same as it was in dovaktsinalny period. Seasonality not expressed, there is a slight increased incidence in the fall and winter.
Infection atriums is the mucous membrane of the respiratory tract. Pertussis bacteria attached to the cells of ciliated epithelium, where they proliferate to the mucosal surface without penetrating the bloodstream. In place of the introduction of the pathogen evolving inflammatory process, inhibited activity of cilia of epithelial cells and increased secretion of mucus. Further there is ulceration of the epithelium of the airways and focal necrosis. The pathological process is most pronounced in the bronchi and bronchioles, less pronounced changes develop in the trachea, larynx and nasopharynx. Muco-purulent cork clog the lumen of small bronchi develops focal atelectasis, emphysema. There peribronchial infiltration. The genesis of seizures is important sensitizing the body to toxins pertussis bacillus. The constant irritation of the respiratory tract causes coughing receptors and leads to the formation in the respiratory center of the focus of excitation of the dominant type. As a result, the typical attacks of spasmodic cough may be caused by non-specific stimuli. From the dominant focus of excitation may radiate to other parts of the nervous system, such as vasomotor (increased blood pressure, vascular spasm). Irradiation of excitation is also due to the appearance of spasmodic contractions of facial muscles and torso, vomiting and other symptoms of pertussis. Transferred whooping cough (pertussis vaccination as) does not provide lifelong immunity busy, so there may be repeated pertussis (about 5% of cases of whooping cough accounts for adults).
Infectiousness period lasts from one week before the cough and 3 weeks after. Since before the characteristic whooping cough distinguish from other infections difficult, for one week the infected manage to infect their surroundings.
Pertussis toxin secreted rod acts directly on the central nervous system, irritates nerve receptors airway mucosa and actuates the cough reflex, resulting in the characteristic seizures occur whooping cough. If the process involves neighboring nerve centers, there is vomiting (typical for the end of the cough attack), cardiovascular disorders (drop in blood pressure, vascular spasm), neurological disorders (cramps).
The incubation period lasts from 2 to 14 days (usually 5-7 days). Catarrhal period is characterized by general malaise, slight cough, runny nose, low grade fever. Gradually the cough intensifies, children become irritable, moody. At the end of the 2nd week of the disease begins a period of spasmodic cough. Attacks of whooping cough begin suddenly, cough manifested by a series of aftershocks, followed by a deep whistling breath – whooping, followed by a series of short again convulsive tremors. The number of such cycles during an attack varies from 2 to 15. The attack ends with the release of a viscous glassy phlegm, sometimes at the end of the attack indicated vomiting. During the attack the child is excited, a person acquires a bluish color, dilated neck veins, bloodshot eyes, the tongue protrudes from his mouth, tongue frenulum often injured, can occur with the development of respiratory arrest suffocation. In young children reprise not expressed. Depending on severity of the disease attacks the number can vary from 5 to 50 per day.
Duration of attacks by an average of 4 minutes.Period whooping cough lasts for 3-4 weeks, then the attacks have become rarer and finally disappear, although “normal” cough continues for 2-3 weeks (the period of authorization). In adults, the disease occurs without attacks whooping cough, bronchitis with manifest long persistent cough. Body temperature remains normal. The general state of health is satisfactory. Erased form of pertussis can occur in children who underwent vaccination.
The most common complication is pneumonia, caused by pertussis stick or a secondary bacterial infection. Among other complications observed acute laryngitis (inflammation of the larynx) with stenosis of the larynx (false croup), bronchiolitis, nosebleeds, respiratory arrest, umbilical, inguinal hernia. It may also occur encephalopathy – a non-inflammatory changes in the brain, which is due to the occurrence of seizures can lead to death or leave behind a persistent damage: deafness or seizures.