Hemophilus infection( Hib infection) - Causes, symptoms and treatment. MF.

Hemophilus infection( Hib infection) is a group of acute infectious diseases caused by Pfeiffer's wand( Figure on the left), with an aerogenic mechanism of infection that affects primarily the children's age group and is characterized by inflammatory processes of the respiratory system, central nervous system with the possible formation of purulent foci in various tissuesand organs( sepsis).

Hemophilus infection is a fairly common disease in the children's age group. The incidence of hemophilic infection is high, but it is difficult to calculate it statistically. One of the reasons is poor registration, because clinically ARI of hemophilic origin differs little from, for example, pneumococcal or staphylococcal infection. Therefore, only severe cases with the development of pneumonia, meningitis and other manifestations can be considered.

The possibility of a healthy carrier during a hemophilic infection raises concerns, since it is an uncontrolled process from the epidemiological point of view. In a number of countries, the frequency of carriage in preschool children reaches 40%, which explains the high incidence of ARI in kindergartens. However, the presence of specific prophylaxis saves this situation up to a reduction in the incidence of cases in a number of European countries. For example, in the UK, the introduction of routine vaccination has reduced the incidence rate to 1-2x cases per year. In our country, a free vaccine has been introduced into the National Vaccination Schedule for only a certain category of children( oncology, HIV infection, immunodeficiencies, and children of the child's homes), so the vaccination company of the remaining children goes solely on the initiative of the parents and depends only on their awareness of the issue.

Pathogen of Hemophilus Infection

The causative agent of is the Haemophilus influenzae type B haemophilus( hence the name Hib).At present, about 16 types of hemophilic rod and 6 antigenically different types( from a to f) are isolated, but the most pathogenic for humans is type B. This gram "-" microorganism( with Gram staining and microscopy is not stained) is very small(diameter up to 1 μm), which can be converted to the S-form( to form a protective polysaccharide capsule).It is this capsule that allows the hemophilic rod to survive long in the human body, deviating from the immune system, as well as from the action of antibacterial drugs."Thanks to" capsule in the child's body, protective antibodies can not be produced for a long time or produced in small amounts, so babies can get sick of this infection many times. Hemophilus influenzae is a conditionally pathogenic microorganism, often a representative of the normal microflora of the human mucosal airway, therefore the frequency of healthy carriage of this pathogen is high.

Hemophilus influenza after staining according to Gram.

. Causes of spreading of hemophilic infection.

. The source of infection of is a patient with a clinically pronounced form of the disease( from ARI to pneumonia, meningitis and sepsis).Also the source of infection is the healthy carriers of the hemophilic rod. In the focus of hemophilic infection, carrier frequency can reach 70% in children and 30-40% in adults.

The infection mechanism is aerogenic, and the pathway is airborne( the spread of the pathogen occurs when sneezing, coughing, talking to the mucus of the bronchial tree - phlegm, and also mucus of the mouth and nasopharynx).The greatest probability of infection in persons in the immediate vicinity of the source of infection( 3 meters or less).The patient becomes contagious with the appearance of the symptoms of the disease. The carrier is externally healthy, hence, the most dangerous from the epidemiological side, however, in such people, the least infectious types of hemophilic rods are isolated. An additional way of infection - contact-household( through household items - towels, dishes, toys).

The season for this infection is winter-spring. Susceptibility to this infection is high among young children - from 6 months to 2 years, and sometimes 4 years. Up to 6 months due to "maternal protection" children are ill rarely. Older than 5 years and adults are ill in isolated cases.

Risk groups for susceptibility to hemophilic infection:

1) Age group of children from 6 months to 2 years.
2) The elderly are older than 65 years.
3) Children who are breastfeeding.
4) Immunodeficiencies( oncological diseases, blood diseases, HIV infection, etc.).
5) Persons after removal of the spleen.
6) Social immunodeficiency( chronic alcoholism, drug addiction).
7) Children from closed institutions( at home, children's homes).

The path of Pfeiffer's wand in the human body:

The entrance gate of the infection is the mucous membrane of the nasopharynx, where the pathogen can be for a long time. The further development of the process largely depends on the local resistance of the mucosa( a decrease in resistance can be caused by frequent colds, hypothermia, stress).With weak resistance, the rod multiplies, accumulates and penetrates into the blood( bacteremia).And then the infection spreads through the favorite organs and tissues( lungs, paranasal sinuses, bone system, central nervous system, and others) with the possibility of developing sepsis( multiple purulent foci).

Symptoms of Hemophilus Infection

The incubation period( from the moment of infection to the appearance of the first symptoms of the disease) is almost impossible to determine, because the hemophilic rod can stay on the mucous membrane of the nasopharynx for a long time without causing any changes( asymptomatic course) and only when the protective forces begin to multiply.

The onset of infection can be similar to acute respiratory disease( ARI), then generalization of the process occurs( the rod penetrates into the blood and spreads through the body) and one of the clinical forms arises.

Several typical forms of hemophilic infection are distinguished:

1) Purulent meningitis( inflammation of the dura mater)
2) Acute pneumonia( inflammation of the lungs)
3) Sepsis, in particular one of its forms - septicemia( systemic disease)
4) Cellulite orpanniculitis( inflammation of the subcutaneous tissue)
5) Epiglottitis( epiglottitis)
6) Acute arthritis( joint damage)
7) Rarer forms( otitis, sinusitis, pericarditis, respiratory tract infection and others).

Purulent meningitis of the hemophilic etiology is the most common cause of meningitis in the children's age group from 6 months to 4 years. The younger the patient's age, the harder the disease goes. The percentage of neurological complications is high - up to 40%, lethality slightly more than 10%.Symptoms are combined into three syndromes:
- infectious-toxic syndrome ( feature is a gradual onset with ARI, high fever up to 38-39 ° and more, redness of face and neck);
- cerebral symptomatology ( headaches expressed, nausea, vomiting, often repeated, hypersensitivity to all kinds of irritants);
- meningeal syndrome ( rigidity of the occipital muscles - impossibility of passive head bending in the prone position, symptoms of Kernig, Brudzinsky).The course of hemophilic meningitis is long, wavy.

Features in children of the first year of life:

1) Equivalent headache - "brain cry" - a long, even constant piercing cry of a child, like a high-tilt howl.
2) Due to the expressed hypersensitivity of the skin, it is impossible to identify meningeal signs. It helps the Lessage symptom( when the child is suspended from the arms under the armpits, the legs are first clamped, and then they do not straighten them, as healthy ones, but keep them in a tight state for a long time).
3) Due to high temperature, a high risk of convulsive syndrome.
4) Children of the first year of life quickly fall into the unconscious state.
5) Bulging of the large fontanel( on the crown of the child).The smaller the size of the large fontanel, the faster the loss of consciousness.
6) Equivalent of vomiting - regurgitation.
7) The indication for the lumbar puncture is the high temperature without other symptoms and the shrill cry of the baby.
Cerebrospinal fluid with lumbar puncture flows under pressure( frequent drops), cloudy, greenish, pleocytosis or an increase in the cellular composition of the CSF of several hundred in 1 μl, neutrophils predominate.

With persistent preservation of the symptoms of meningitis, as well as the attachment of seizures, the second wave of fever, psycho-motor excitement of the patient, one should think about adherence of ventriculitis( inflammation of the ventricles of the brain), as well as subdural suppuration.

What should I call a doctor? Persistent high fever, headache or constant crying of the child, vomiting or regurgitation, muscle twitching. Do not wait, urgently call an ambulance.

Acute pneumonia. One of the common causes of pneumonia in children is a hemophilic rod. Pneumonia can be focal or croupous( with a loss of a lobe or a few lobes), often complicated by pleurisy( inflammation of the pleura - lung membranes) - up to 70% of cases in children. The patient has a high fever, weakness, lethargy, cough, first dry or unproductive, and then becomes wet( sputum purulent with a yellowish tinge).Often disturbances of a respiratory excursion, which is manifested by shortness of breath. The course of pneumonia is protracted, difficult to treat, it can be wavy.

Hemophilus pneumonia

To the doctor will force: high fever, child lethargy, refusal to eat, drowsiness, regurgitation, coughing and vomiting.

Septicemia is a systemic disease caused by the penetration of the hemophilic rod into the blood, which has various clinical manifestations. More often hemophilic sepsis occurs among children 6-12 months. It flows like a gram of "-" sepsis - without the appearance of secondary purulent foci, it is difficult, even lightning fast. There is a high probability of septic shock and death.
It is characterized by high temperature( up to 40 °), enlarged spleen, rapid hemodynamic disturbances( blood pressure drop, increased heart rate), microcirculation disorders appear( hemorrhages on the skin of the trunk, limbs, face).Mortality is high.

Hemophilus sepsis

What will cause you to see a doctor? High fever, lethargic child refusal to eat, drowsiness, pale skin, blue lips, frequent palpitations, small to large bleeding on the skin, decreased frequency of urination. Urgently call an ambulance.

Cellulite often develops in children under one year. Against the backdrop of a picture of acute respiratory disease, there is a swelling in the affected area( usually a person, less often a limb).In the area of ​​the lesion lesion, reddening of the skin with a bluish tinge, swelling, soreness when probed. Sometimes it can be accompanied by other symptoms( for example, inflammation of the middle ear - otitis media).The temperature in most cases is small( 37-37.5 °).

Hemophilous orbital cellulite

Epiglottitis is mainly found in children from 2 to 4-5 years old and is characterized by severe course. Against the background of high fever, there are severe pains in the throat, swallowing problems, and breathing disorders due to the narrowing of the larynx in the area of ​​the inflamed epiglottis. The patient has a speech disorder( dysphonia), pale skin, excessive salivation, head tilting. When examining the throat and pressing the spatula on the root of the tongue, you can see a bright red epiglottis. When laryngoscopy - inflammation of the epiglottis, swelling in the subglottic space. If you do not help in time, you can completely block the larynx in the area of ​​inflammation, including loss of consciousness and death. The patient urgently needs intubation or tracheostomy.

To the doctor to apply when: the appearance of severe pain in the throat and tilting the child's head, shortness of breath on this background, inability to swallow a sip of water and utter a word, high fever.

Acute arthritis - rarely isolated. On the background of acute respiratory disease, one or more joints of the limbs become affected. Sometimes arthritis is complicated by inflammation of the bone tissue( osteomyelitis).

Complications of hemophilic infection

- Brain edema due to the development of hemophilic meningitis with a syndrome of wedging of the cerebellar tonsils into the large occipital foramen and death.
- Acute respiratory failure due to acute pneumonia.
- Asphyxia( obstruction of the respiratory tract) due to epiglottitis with the development of respiratory failure and death.
- Septic shock due to septicemia with the development of hemodynamic disorders, microcirculation and death.

After the infection, persistent long-term immunity is formed. Repeated diseases are possible only in immunocompromised individuals.

Diagnosis of Hemophilus Infections

Preliminary diagnosis is based on the patient's age( from 6 months to 4 years mainly), characteristic symptoms( appearance of the most common forms on the background of ARI - meningitis, pneumonia, sepsis, etc.).The similarity of clinical symptoms with virtually all bacterial infections reduces diagnostics to early laboratory confirmation. In the general analysis of blood - reduction of erythrocytes( anemia), an increase in leukocytes, neutrophils, ESR.

The final diagnosis is after a laboratory test. Materials for the study - nasopharyngeal mucus, sputum, spinal fluid, blood, purulent contents of lesions. Methods:
- bacteriological( seeding material on blood agar, chocolate agar);
- bacterioscopic( microscopy of Gram-doped preparations);
- detection of capsular antigen by the reaction of counter immunoelectrophoresis;
- serological tests( latex-agglutination reaction, micro-precipitation).

Treatment of hemophilic infection

1. Organizational-regime measures( hospitalization of children with moderate and severe forms of infection in hospital, bed rest for the entire febrile period, proper nutrition with the exception of heavily salted food, abundant drinking according to indications)

2. Etiotropic antibacterial therapyis assigned prior to the results of a laboratory study) in order to prevent severe complications of hemophilic infection. In severe form, the drugs of choice are cephalosporins of III and IV generations, carbapenems, ampicillin, aminoglycosides. With lighter forms - amoxicillin, cefaclor. With resistance to ampicillin, levomycetin is prescribed, but it is prescribed less often. The duration of treatment depends on the clinical form of the infection: from 7 to 14 days. Only the doctor prescribes the drug. Independent home use can lead to disastrous consequences( complications).

3. Pathogenetic therapy is carried out in a hospital and involves the restoration of impaired functions of vital organs and systems( detoxification infusion therapy, prevention of complications).

4. Asynchronous therapy
• antipyretic drugs( panadol, nurofen, efflergan and others);
• vasoconstrictive drops in the nose( aquamaris infants, nazivin, nazol, tizin, otrivin and others);
• expectorants( lazolvan, ambroxol, gedelix);
• for cellulite and epiglotitis the basis of treatment is antibacterial therapy.

Mild forms of the disease can occur under the mask of ARI, but in any case, later on, either sinusitis, or sinusitis, or bronchitis, or otitis will manifest. That is, when you see a doctor, antibiotics should be prescribed. If there is no etiotropic treatment, in most cases a clinical form of hemophilic infection will form, that is, the prognosis will be with the heavier disease.

Prevention of Hemophilus Infection

There is a specific prevention - a vaccine. In Russia, the Act-HIB( France) was registered. The vaccine contains a capsular polysaccharide of the haemophilic rod type b, combined with tetanus toxoid, in order to be able to administer it and develop immunity from a 2-month age of life. Requires 3x administration.

Vaccination in children's groups allows to significantly reduce the frequency of hemophilic infection among often ill children. The burden of vaccination may decrease from 40% to 3%, as can be seen in the example of vaccination of children in the Moscow region. Similar effects have been made public in other areas of Russia.

The doctor infektsionist Bykova N.I.