Diphtheria is an acute infectious disease of bacterial nature characterized by the development of fibrinous inflammation in the area of the introduction of the pathogen (mainly the upper respiratory tract, the mucous membrane of the oropharynx is affected). Diphtheria is transmitted by airborne droplets and airborne dust. The infection can affect the oropharynx, larynx, trachea and bronchi, eyes, nose, skin and genitals. Diagnosis of diphtheria is based on the results of bacteriological examination of a smear from the affected mucosa or skin, examination data and laryngoscopy. If myocarditis and neurological complications occur, a cardiologist and a neurologist should consult.
ICD 10
A36 Diphtheria
Causes
Diphtheria is caused by Corynebacterium diphtheriae, a gram-positive immobile bacterium that looks like a stick, at the ends of which there are grains of volutin, giving it the appearance of a mace. Diphtheria bacillus is represented by two main biowars and several intermediate variants. The pathogenicity of the microorganism consists in the release of a potent exotoxin, second only to tetanus and botulinum in toxicity. Bacterial strains that do not produce diphtheria toxin do not cause disease.
The pathogen is resistant to the effects of the external environment, is able to persist on objects, in dust for up to two months. Tolerates low temperature well, dies when heated to 60 ° C after 10 minutes. Ultraviolet irradiation and chemical disinfectants (lysol, chlorine-containing agents, etc.) have a detrimental effect on Diphtheria bacillus.
The reservoir and source of diphtheria is a sick person or a carrier that secretes pathogenic strains of Diphtheria bacillus. In the vast majority of cases, infection occurs from sick people, the most epidemiological significance is erased and atypical clinical forms of the disease. The release of the pathogen during the convalescence period can last 15-20 days, sometimes extending to three months.
Diphtheria is transmitted by an aerosol mechanism mainly by airborne droplets or airborne dust. In some cases, it is possible to implement a contact-household path of infection (when using contaminated household items, dishes, transmission through dirty hands). The pathogen is able to multiply in food products (milk, confectionery), contributing to the transmission of infection by alimentary means.
People have a high natural susceptibility to infection, after the transfer of the disease, antitoxic immunity is formed, which does not prevent the carrier of the pathogen and does not protect against repeated infection, but contributes to a lighter course and the absence of complications in case of its occurrence. Children of the first year of life are protected by antibodies to diphtheria toxin transmitted from the mother transplacentally.
Classification
Diphtheria differs depending on the localization of the lesion and the clinical course into the following forms:
- oropharyngeal diphtheria (localized, widespread, subtoxic, toxic and hypertoxic);
- diphtheria croup (localized laryngeal croup, common croup when the larynx and trachea are affected, and descending croup when it spreads to the bronchi);
- diphtheria of the nose, genitals, eyes, skin;
- combined lesion of various organs.
Localized oropharyngeal diphtheria can occur in catarrhal, insular and filmy variants. Toxic diphtheria is divided into the first, second and third degrees of severity.
Diphtheria symptoms
Oropharyngeal diphtheria develops in the vast majority of cases of infection with Diphtheria bacillus. 70-75% of cases are represented by a localized form. The onset of the disease is acute, the body temperature rises to febrile numbers (subfebrility is less often preserved), symptoms of moderate intoxication appear (headache, weakness, loss of appetite, paleness of the skin, increased pulse rate), sore throat. The fever lasts 2-3 days, by the second day the plaque on the tonsils, previously fibrinous, becomes denser, smoother, acquires a pearlescent sheen. The raids are removed hard, leaving areas of bleeding mucosa after removal, and the next day the cleaned place is again covered with a fibrin film.
Localized oropharyngeal diphtheria manifests itself in the form of characteristic fibrinous plaque in a third of adults, in other cases, the plaque is loose and easily removable, leaving no bleeding behind. Such are typical diphtheria attacks 5-7 days after the onset of the disease. Inflammation of the oropharynx is usually accompanied by a moderate increase and sensitivity to palpation of regional lymph nodes. Inflammation of the tonsils and regional lymphadenitis can be both unilateral and bilateral. Lymph nodes are affected asymmetrically.
Localized diphtheria rarely occurs in the catarrhal variant. In this case, subfebrility is noted, or the temperature remains within the normal range, intoxication is not pronounced, hyperemia of the mucous membrane and some swelling of the tonsils are noticeable when examining the oropharynx. Pain when swallowing is moderate. This is the mildest form of diphtheria. Localized diphtheria usually ends in recovery, but in some cases (without proper treatment) it can progress into more common forms and contribute to the development of complications. Usually, the fever goes away for 2-3 days, the tonsils are attacked for 6-8 days.
Widespread oropharyngeal diphtheria is observed quite rarely, in no more than 3-11% of cases. In this form, the raids are detected not only on the tonsils, but also spread to the surrounding mucous membrane of the oropharynx. At the same time, the general intoxication syndrome, lymphadenopathy and fever are more intense than with localized diphtheria. The subtoxic form of oropharyngeal diphtheria is characterized by intense pain when swallowing in the throat and neck area. When examining the tonsils, they have a pronounced purple color with a cyanotic tinge, covered with plaque, which are also noted on the tongue and palatine arches. This form is characterized by swelling of subcutaneous tissue over compacted painful regional lymph nodes. Lymphadenitis is often unilateral.
Currently, a toxic form of oropharyngeal diphtheria is quite common, often (in 20% of cases) developing in adults. The onset is usually violent, body temperature rises rapidly to high values, an increase in intense toxicosis, lip cyanosis, tachycardia, arterial hypotension is noted. There is severe pain in the throat and neck, sometimes in the stomach. Intoxication contributes to the disruption of central nervous activity, nausea and vomiting may occur, mood disorders (euphoria, excitement), consciousness, perception (hallucinations, delirium).
Toxic diphtheria of the II and III degrees can contribute to intense oropharyngeal edema that prevents breathing. The raids appear quickly enough, spread along the walls of the oropharynx. The films thicken and roughen, the plaque persists for two or more weeks. Early lymphadenitis is noted, the nodes are painful, dense. Usually the process captures one side. Toxic diphtheria is characterized by the existing painless swelling of the neck. The first degree is characterized by edema limited to the middle of the neck, in the second degree it reaches the collarbones and in the third degree it spreads further to the chest, face, back of the neck and back. Patients note an unpleasant putrid smell from the mouth, a change in the timbre of the voice (rhinophony).
The hypertoxic form is the most severe, usually develops in people suffering from severe chronic diseases (alcoholism, AIDS, diabetes mellitus, cirrhosis, etc.). Fever with tremendous chills reaches critical figures, tachycardia, low-filling pulse, drop in blood pressure, pronounced pallor in combination with acrocyanosis. With this form of diphtheria, hemorrhagic syndrome may develop, infectious and toxic shock with adrenal insufficiency may progress. Without proper medical care, death can occur as early as the first or second day of the disease.
Diphtheria croup
With localized diphtheria croup, the process is limited by the mucous membrane of the larynx, with a common form, the trachea is involved, and with descending croup, the bronchi. Often, croup accompanies oropharyngeal diphtheria. More and more recently, this form of infection has been observed in adults. The disease is usually not accompanied by significant general infectious symptoms. There are three consecutive stages of croup: dysphonic, stenotic and asphyxia stage.
The dysphonic stage is characterized by the appearance of a rough “barking” cough and progressive hoarseness of the voice. The duration of this stage ranges from 1-3 days in children to a week in adults. Then aphonia occurs, the cough becomes soundless – the vocal cords are stenosed. This condition can last from several hours to three days. Patients are usually restless, when examined, they note the pallor of the skin, noisy breathing. Due to the difficulty of air passage, there may be retractions of intercostal spaces during inhalation.
The stenotic stage turns into an asphyxic one – the difficulty of breathing progresses, becomes frequent, arrhythmic up to a complete stop as a result of obstruction of the respiratory tract. Prolonged hypoxia disrupts the brain and leads to death from suffocation.
Diphtheria of the nose
It manifests itself in the form of difficulty breathing through the nose. With a catarrhal variant of the course – discharge from the nose of a serous-purulent (sometimes hemorrhagic) nature. Body temperature, as a rule, is normal (sometimes subfebrile), intoxication is not pronounced. The nasal mucosa is ulcerated during examination, fibrinous deposits are noted, which are removed like shreds in the film version. The skin around the nostrils is irritated, maceration, crusts may occur. Most often, nasal diphtheria accompanies oropharyngeal diphtheria.
Diphtheria of the eyes
The catarrhal variant manifests itself in the form of conjunctivitis (mainly unilateral) with moderate serous discharge. The general condition is usually satisfactory, there is no fever. The filmy variant is characterized by the formation of fibrinous plaque on the inflamed conjunctiva, swelling of the eyelids and separable serous-purulent character. Local manifestations are accompanied by subfebrility and mild intoxication. The infection can spread to the second eye.
The toxic form is characterized by an acute onset, rapid development of general intoxication symptoms and fever, accompanied by pronounced swelling of the eyelids, purulent hemorrhagic discharge from the eye, maceration and irritation of the surrounding skin. The inflammation spreads to the second eye and surrounding tissues.
Diphtheria of the ear, genitals (anal-genital), skin
These forms of infection are quite rare and, as a rule, are associated with the peculiarities of the method of infection. Most often combined with oropharyngeal or nasal diphtheria. They are characterized by edema and hyperemia of the affected tissues, regional lymphadenitis and fibrinous diphtheria deposits. In men, diphtheria of the genitals usually develops on the foreskin and around the head, in women – in the vagina, but it can easily spread and affect the small and large labia, perineum and anus. Diphtheria of the female genital organs is accompanied by hemorrhagic secretions. When the inflammation spreads to the urethra area, urination causes pain.
Diphtheria of the skin develops in places of damage to the integrity of the skin (wounds, abrasions, ulceration, bacterial and fungal lesions) in case of contact with the pathogen. It manifests itself as a gray plaque on the area of hyperemic edematous skin. The general condition is usually satisfactory, but local manifestations can exist for a long time and slowly regress. In some cases, asymptomatic carriage of diphtheria bacillus is registered, more often characteristic of persons with chronic inflammation of the nasal cavity and pharynx.
Complications
Diphtheria is most often and dangerously complicated by infectious-toxic shock, toxic nephrosis, adrenal insufficiency. Possible lesions from the nervous (polyradiculoneuropathy, neuritis) cardiovascular (myocarditis) systems. Toxic and hypertoxic diphtheria is the most dangerous from the point of view of the risk of fatal complications.
Diagnostics
The blood test shows a picture of a bacterial lesion, the intensity of which depends on the form of diphtheria. Specific diagnosis is made on the basis of bacteriological examination of a smear from the mucous membranes of the nose and oropharynx, eyes, genitals, skin, etc. Back-sowing on nutrient media must be carried out no later than 2-4 hours after the material is taken.
The determination of the increase in the titer of antitoxic antibodies is of auxiliary importance, it is performed using RNG. Diphtheria toxin is detected by PCR. Diagnosis of diphtheria croup is made by examining the larynx with a laryngoscope (there is swelling, hyperemia and fibrinous films in the larynx, in the glottis, trachea). With the development of neurological complications, a patient with diphtheria needs to consult a neurologist. When signs of diphtheria myocarditis appear, a cardiologist’s consultation, an ECG, and an ultrasound of the heart are prescribed.
Diphtheria treatment
Patients with diphtheria are hospitalized in infectious departments, etiological treatment consists in the administration of anti-diphtheria antitoxic serum according to a modified method Occasionally. In severe cases, intravenous administration of serum is possible.
The complex of therapeutic measures is supplemented with drugs according to indications, with toxic forms, detoxification therapy is prescribed with the use of glucose, cocarboxylase, the introduction of vitamin C, if necessary – prednisolone, in some cases – plasmapheresis. With the threat of asphyxia, intubation is performed, in cases of obstruction of the upper respiratory tract – tracheostomy. If there is a threat of secondary infection, antibiotic therapy is prescribed.
Prognosis and prevention
The prognosis of localized forms of diphtheria of mild and moderate severity, as well as with timely administration of antitoxic serum, is favorable. The prognosis may be aggravated by the severe course of the toxic form, the development of complications, and the late onset of therapeutic measures. Currently, due to the development of patient care and mass immunization of the population, the mortality rate from diphtheria is no more than 5%.
Specific prevention is carried out on a planned basis for the entire population. Vaccination of children begins at the age of three months, revaccination is carried out at 9-12 months, 6-7, 11-12 and 16-17 years. Vaccinations are carried out with a complex vaccine against diphtheria and tetanus or against whooping cough, diphtheria and tetanus. If necessary, adults are vaccinated. Patients are discharged after recovery and a double negative bacteriological examination.