Meningococcal infection
The content of the article:
- Causes and risk factors
- Forms of the disease
- Disease stages
-
Symptoms
- Meningococcal nasopharyngitis
- Meningococcemia
- Waterhouse-Friederiksen syndrome
- Meningococcal meningitis and meningoencephalitis
- Features of the course of meningococcal infection in children
- Diagnostics
- Treatment
- Possible complications
- Prevention
- Video
Meningococcal disease is caused by meningococci and can take a variety of forms, from asymptomatic carriage to severe meningococcal sepsis (meningococcemia). Children get sick more often.
The causative agent of meningococcal infection refers to diplococci, bacteria that form pairs
Causes and risk factors
The causative agent of meningococcal infection is the gram-negative microorganism Neisseria meningitidis, which belongs to diplococci, i.e., round bean-shaped bacteria that form a pair. Meningococcus does not have flagella and cannot move, but it has a capsule that protects it from phagocytosis when it enters the body. Does not form a dispute. This type of infection is anthroponous, which means transmission only from person to person. Meningococcus is very unstable in the external environment, its life outside the human body is about half an hour. It is transmitted by airborne droplets, the source of infection is a sick person or an asymptomatic carrier. There are 12 known serotypes of the pathogen, some of which (A, B, C, W, X and Y) can cause epidemic outbreaks.
Susceptibility to meningococci is quite high and the infection is widespread, however, when infected, not everyone gets sick, but only people with weakened immunity - for this reason, children are more susceptible to the disease, due to insufficient maturity of the immune system.
In most patients, meningococcal infection causes acute nasopharyngitis, which in its course differs little from the usual acute respiratory infections. Inhalation of aerial suspensions containing Neisseria meningitidis enters the nose and / or mouth, spreads through the nasopharynx and causes inflammation, which, although acute, usually resolves within a few days. However, in some people, the infection penetrates into other organs and systems, affecting them, and in severe cases it takes a severe generalized form. Meningococci are able to cross the blood-brain barrier, entering the brain and affecting the meninges (meningitis), and sometimes the brain tissue itself (meningoencephalitis).
The main risk factor, therefore, is a decrease in the body's defenses. The complicated epidemic situation and overcrowding are also important, especially in children's institutions.
There is some seasonality of the incidence - the risk of getting sick increases in the spring months, although it is not zero throughout the year.
After the transferred disease, a fairly stable immunity is formed, but it has a group-specific character, which means resistance to only one serotype of the pathogen. Repeated cases of the disease are extremely rare, however, they are not excluded when infected with meningococcus of a different serotype.
Forms of the disease
The disease can occur in a latent form - the carrier of bacteria. Carriage of bacteria occurs when the immune system is not strong enough to prevent infection, but strong enough to prevent disease from developing.
The most common form of meningococcal infection that most people infected with is acute nasopharyngitis. However, if the pathogen manages to overcome the local barrier, it enters the bloodstream and spreads throughout the body, acquiring a generalized character. In this case, they speak of meningococcemia, which can lead to meningitis, meningoencephalitis, or the development of combined forms (any combination of one or more generalized forms). Generalized forms of meningoinfection account for 0.5% of all cases of infection with Neisseria meningitidis
Meningococci, spreading through the body with blood flow, can infect not only the nasopharynx or brain tissues, but also distant organs and tissues - the heart (myocarditis), joints (arthritis), the iris of the eyes (iridocyclitis), etc., but this happens seldom.
Forms of meningoinfection:
| Localized | Generalized | Rare |
| Carrier bacteria | Meningitis | Arthritis |
| Nasopharyngitis | Meningoencephalitis | Pneumonia |
| Meningococcemia | Myocarditis, etc. |
Disease stages
Like most infectious diseases, meningoinfection has four main stages: latent, disease onset, peak and resolution, but in some forms not all of them are expressed. For example, transient bacteremia is an asymptomatic form of meningococcemia that has only one, latent stage, and is detected by chance.
In other cases, the latent period is not visible, the disease has an acute onset.
The heat stage in most cases ends with convalescence, or recovery. However, in severe generalized forms of the disease, such as Waterhouse-Friederiksen syndrome, there is a high risk of death.
Symptoms
The manifestations of meningococcal infection vary depending on the location and severity of the lesion, from the complete absence of bacterial carriage or local inflammation (for example, inflammation of the joints) to infectious toxic shock.
Meningococcal nasopharyngitis
Nasopharyngitis caused by Neisseria meningitidis begins acutely - the body temperature rises to subfebrile values (37.5-38 ° C), pain appears during swallowing, sore throat, stuffy nose, later a runny nose occurs. The general well-being worsens. The disease develops as nasopharyngitis of any other etiology, and lasts the same amount - 5-7 days, after which the patient usually recovers.
Sometimes the disease has mild symptoms, in particular, it proceeds without an increase in temperature or with a slight increase (37-37.2 ° C).
Meningococcemia
Meningococcemia, or meningococcal sepsis, can be acute or due to poor outcomes of meningococcal nasopharyngitis. More often, the disease begins suddenly, with the onset of malaise, which is rapidly increasing, the temperature rises to febrile values (38-39 ° C), the appearance of a severe headache. The skin becomes pale with a cyanotic shade, the patient becomes covered with cold clammy sweat. By the end of the first day of illness, a rash usually appears. At first, it looks like roseola of different sizes, is located throughout the body, disappears if you press on it. Later, foci of hemorrhage appear, they are bright or dark red, located above the level of the skin, mainly on the lower side of the body (back, buttocks, thighs, legs, heels). By the end of the second day, the roseolous rash disappears, and the hemorrhagic foci, on the contrary, increase and darken. If the focus is large, areas of necrosis can form in its center - dead and rejected tissue, subsequently, after recovery, a scar forms in its place.
Foci of hemorrhage with meningococcemia
Waterhouse-Friederiksen syndrome
This is a fulminant form of meningococcemia, which is characterized by an extremely violent course, leading to the development of an infectious-toxic shock. This form is relatively rare - it accounts for 10-20% of generalized meningoinfection. Has a poor prognosis.
It starts suddenly, the symptoms grow very quickly, the general condition of the patient suffers significantly. The body temperature rises very quickly to 40 ° C and higher, blood pressure at first rises slightly, then decreases, tachycardia appears, breathing is disturbed. Consciousness becomes confused, subsequently the patient is lost. Convulsions may occur. Hemorrhagic skin rashes appear quickly, within a few hours. The elements of the rash quickly increase in size, merging into extensive hemorrhagic foci of a dark color, often this happens literally before our eyes. Subsequently, the body temperature decreases, which is an unfavorable sign indicating the depletion of adaptive mechanisms. If the patient does not receive timely qualified medical care, the disease ends in death.
Meningococcal meningitis and meningoencephalitis
Like most other forms of meningoinfection, it begins acutely - with a rise in body temperature to febrile values, deterioration of the general condition and the appearance of intense headache. The pain increases with any stimuli (noise, light, tactile), change in body position, head movements; accompanied by nausea and vomiting. Vomiting is not associated with food intake, it can be repeated, there is no relief after it. As the disease develops, the heart rate increases, shortness of breath occurs, consciousness is impaired, convulsions may appear, the patient falls into a coma. This form of meningoinfection, although it has a less rapid development than fulminant meningococcemia, without adequate medical care can have the same consequences due to the developed cerebral edema.
Features of the course of meningococcal infection in children
Children, especially the first year of life, constitute the most vulnerable group in relation to meningoinfection, and suffer from it more than adults. The most common generalized forms of the disease develops in young children (up to three years).
The onset of the disease is sudden, often parents can accurately name the time when the first symptoms appear. It begins with a rise in temperature to febrile values, vomiting, a sharp deterioration in general condition and the appearance of a severe headache. Babies react to this by crying, for which there is a special term - brain cry, it has a monotonous constant character. The child takes a forced posture, does not allow him to touch his head, reacts negatively to any stimuli. If you experience such symptoms, you should immediately consult a doctor.
Diagnostics
The main method for diagnosing meningoinfection is a bacteriological study, which confirms the presence of the pathogen, the bacterium Neisseria meningitidis, in the test material. With meningococcal nasopharyngitis, a scraping from the nasopharyngeal mucosa is taken for research, however, such a study is rarely performed, since the disease is not much different from nasopharyngitis of another etiology, has a mild or moderate severity and does not cause concern about the particular danger of the pathogen.
The primary diagnosis of generalized forms is based on clinical data (acute onset, high fever, meningeal symptoms, the presence of characteristic hemorrhagic rashes), a laboratory test is performed to verify the diagnosis. The diagnosis is confirmed by the detection of meningococci in the test material. The material for bacteriological research is cerebrospinal fluid, which is obtained by resorting to lumbar puncture, mucus of the upper respiratory tract, and blood. To determine the serotype of the pathogen, serodiagnosis (RNGA, ELISA) is performed, which is of epidemiological significance.
Treatment
Etiotropic, that is, eliminating the cause of the disease, treatment is antibiotic therapy. It is prescribed both for the detection of meningococcal nasopharyngitis, and for all other forms, including asymptomatic bacterial carriers. With generalized infection, antibacterial treatment is carried out by periodically checking the state of the cerebrospinal fluid.
Generalized forms of meningoinfection are treated in a hospital setting, where there is access to resuscitation equipment. In addition to etiotropic treatment, measures are taken to maintain life support in conditions of severe infectious intoxication, detoxification, rehydration, accompanied by forced diuresis, are prescribed antipyretic and sedative drugs. At the stage of recovery, nootropic drugs and other stimulants are prescribed.
Possible complications
Generalized forms of meningeal infection are characterized by a high risk of complications. Foci of necrosis that develop with meningococcemia can affect large areas, for example, limbs, which leads to their amputation. Previous meningitis can have long-term consequences in the form of various neurological disorders. The most formidable complication of generalized meningoinfection is infectious-toxic shock with adrenal insufficiency, which, with a high degree of probability, leads to the death of the patient.
Prevention
Specific and non-specific measures for the prevention of meningococcal infection have been developed. The first is vaccination. There are several types of vaccines that target the most epidemically unsafe serotypes of meningococcus. For example, in the so-called meningitis belt, which covers several African countries, a vaccine is used against serotype A, which most often causes epidemic outbreaks of meningitis in the region. In most European countries, the meningitis vaccine is not included in the mandatory vaccination schedule, but is recommended.
Menactra - meningitis vaccine
People who have had direct contact with a patient with meningoinfection or an identified carrier of bacteria are shown prophylactic antibiotics.
Non-specific prevention consists of general sanitary measures:
- avoiding crowded places during outbreaks of the disease;
- regular wet cleaning and airing of premises;
- careful adherence to the rules of personal hygiene;
- strengthening the body's defenses.
Video
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Anna Kozlova Medical journalist About the author
Education: Rostov State Medical University, specialty "General Medicine".
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
