Haemophilus influenzae meningitis in children
Introduction
Brief introduction of pediatric haemophilic influenza bacillus meningitis Hemophilic influenza bacillus meningitis (hemophilus influenzalmeningitis) is more common, the incidence of which is second only to meningitis and pneumococcal meningitis, more common in infants from 3 months to 3 years old. The clinical manifestations of various brains caused by various bacteria are similar, which can be summarized as central infection manifestations, symptoms of increased intracranial pressure and meningeal irritation. basic knowledge The proportion of illness: 0.34% (the above is the probability of illness in infants and young children) Susceptible people: children Mode of infection: respiratory transmission Complications: hydrocephalus, intracranial hypertension syndrome, brain abscess, septic shock, phlebitis, deafness
Cause
Causes of pediatric haemophilic influenza bacillus meningitis
(1) Causes of the disease
The blood-thirsty influenza bacillus is a Gram-negative short bacillus, which is 1 to 1.5 m long and 0.3-0.4 m wide. The tip is round and is spherical or double-spherical in the cerebrospinal fluid of the patient, sometimes arranged in a short chain. Oxygen bacteria, which are incomplete due to the oxidoreductase system, require two growth cofactors of "X" and "V" during growth. The "X" factor is present in hemoglobin and is resistant to high heat. The "V" factor exists in In the serum, the heat resistance is poor, and the "V" factor in the blood is suppressed. When the temperature is 75 to 100 ° C for 5 to 10 minutes, the inhibitor is destroyed and the chocolate medium is best. Influenza bacilli and Staphylococcus aureus are cultured on the same blood agar plate. Since Staphylococcus can synthesize more "V" factor and diffuse into the medium, it can promote the growth of influenza bacillus. The colonies of influenza bacilli that can grow around the colonies of staphylococcus are slightly larger. The smaller the colony of influenza bacilli, the farther away from the colonies of staphylococci, is called the satellite phenomenon, which is helpful for the identification of this bacterium.
There are onset in the whole year, but it is more common in winter and spring, and there are very few in summer. One child has two children at the same time. There are many reports in the literature, which means that it can account for 3%, which shows that it is contagious.
(two) pathogenesis
According to the different polysaccharide antigens contained in the capsule of influenza bacillus, it is divided into a-f6 type, and the bacterial type of meningitis is about 90%, which is a type B with strong virulence. It has been confirmed that the antigen is polyribose phosphate. (PRP), followed by f-type, non-capsular can not be classified is generally non-pathogenic bacteria, often present in the nasopharynx, bacterial endotoxin plays an important role in the pathogenesis, does not produce exotoxin.
Influenza bacilli invade the nasopharynx first, causing sepsis, recurrence of meningitis. The vast majority of sick children have a small amount of serum antibody in the recovery period, but few people have influenza bacillus meningitis. The reason has not yet been elucidated. It is believed that the antibody of capsular antigen plays a major role in immunity. Most people have no obvious symptoms of nasopharyngeal infection, but they have immunity. The newborn has specific antibodies from the mother, which can be protected. Mostly infants from 3 months to 3 years old.
Prevention
Prevention of meningococcal meningococcal meningitis in children
Because influenza bacilli may cause secondary cases, and the brain is a serious infection, it is advocated that the close contacts of children under 6 years old in the family or child care institutions should be prevented from taking drugs. Rifampic 20mg/(kg · d), 2 times orally, each dose does not exceed 60mg, for 4 days, can have a preventive effect.
There are 6 types of vaccines in foreign countries, which are used for children aged 2 to 60 months. They are safe and reliable. The anti-Hib lipopolysaccharide envelope-phospho-polyribosome (PRP) antibody is a protective antibody, and the immunity of PRP is higher. Poor, protein-bound PRP vaccine is more immune, can produce protective antibodies in children over 2 months. There are currently 4 protein-binding PRP vaccines. In 1987, the United States began to inoculate combined bacteria for children over 18 months. Miao, inoculated in infants of more than 2 months in 1990, the initial age of China is 7 to 11 months, intramuscular injection of 0.5 ml of bacterin in the hips, intensive injection 1 time after 2 months, inoculation of Hib combined vaccine There were few side effects, 25% of the vaccinates had a partial local mild pain, and the injection site was red and swollen and disappeared within 24 hours.
The main measure for prevention of this disease is vaccination with active immunization. Initially, the capsular polyphosphate phosphate (PRP) of the simple b-type bacteria was used as a vaccine, and the immune effect was not satisfactory. Later, a variety of conjugate vaccines were used, namely, PRP and diphtheria toxoid or tetanus toxoid, or pertussis, outer membrane protein of Neisseria meningitidis B group, and the like, which significantly improved the immune effect and improved the protection rate. 80% to 90%. Granoff et al. injected a diphtheria and tetanus vaccine into the newborn, and then vaccinated with a combination of PRP and tetanus. The obtained antibody was 2 to 3 times higher than that of the conjugate vaccine alone. Englund et al. vaccinated the third pregnant woman: PRP and diphtheria toxoid conjugate vaccine, the blood antibody was 171g / L during childbirth, the control group was 1.2g / L, the cord blood was 29.3g / L and 0.29g / L This method of immunization is beneficial to both pregnant women and newborns.
Haemophilus influenzae type b conjugate vaccines are very effective and safe for infants and young children. Finland began vaccination in 1988 until 1990 when the incidence dropped by 90%; Sweden inoculated in 1992, the incidence rate dropped by 92% in 1994; the United States since the use of Hib conjugate vaccine in 1988, 95% in 1993.
The World Health Organization has included Hib conjugate vaccines in the Expanded Immunization Program (EPI), which is used in more than 80 countries around the world. China introduced Hib vaccine in 1998, and it has been used in some provinces with significant preventive effects. In China, the initial age was 7 to 11 months, and 0.5 ml of bacterin was injected intramuscularly, and the injection was boosted once every 2 months. The side effects of inoculation with Hib-conjugated vaccine were few, 25% of the vaccinates had transient local mild pain, and the injection site was red and swollen and disappeared within 24 hours.
In addition, promoting breastfeeding, reducing close contact with patients with asymptomatic carriers or invasive diseases, regulating the use of antibiotics, and improving the sanitation of the living environment are also important steps that need to be taken seriously.
Complication
Complications of pediatric haemophilic influenza bacillus meningitis Complications hydrocephalus intracranial hypertension syndrome brain abscess septic shock phlebitis deafness
10% of children still have fever after 10 days of treatment, which is caused by viral infection. Another 20% to 50% of children with fever are other factors that cannot be ignored, such as drug fever, phlebitis, subdural effusion, followed by Focal arthritis, pleurisy, pericarditis, etc., especially <6 months infants are prone to ventriculitis, persistent convulsions may also be caused by local vascular obstruction, hydrocephalus, intracranial hypertension syndrome, brain abscess Endotoxin-induced septic shock has been reported, DIC is rare, 10% of children have unilateral or bilateral deafness, so should be used for hearing monitoring, other learning ability, mental retardation, vision loss, cranial nerve palsy, paralysis For the temporary, it is also expected to be cured.
Symptom
Children with bloodthirsty influenza, meningitis, meningitis symptoms, common symptoms, meningeal irritation, neck, strong appetite, lack of energy, angular bow, anti-face color, pale, easy to irritate, suffocating, full of heat, cold, hot, body aches
Symptoms vary depending on the age of the child and the morning and evening visits. There are more obvious prodromal symptoms, common hooliganism, cough, etc. After several days or 1 to 2 weeks, meningeal irritation occurs, and the clinical manifestations are mainly caused by various bacteria. The brain is similar to the central infection, the symptoms of increased intracranial pressure and meningeal irritation, but the performance of different age groups is also different.
1. Childhood meningitis: similar to adult clinical manifestations, acute onset, high fever, headache, vomiting, loss of appetite, apathetic, conscious when onset, progression can be found drowsiness, paralysis, even convulsions, coma, severe Frequent convulsions, coma within 24h, visible disturbances during physical examination, neck stiffness, angular arch reversal, Kellyig sign, Bruzinski sign, Babinski sign positive.
2. Infant meningitis: Because the baby is not anterior, the suture can be split, the intracranial hypertension and meningeal irritation can be atypical, the first to irritate, irritability, vomiting, pale, followed by lethargy, crying sharp Eyes are dazed, binocular gaze, the most prone to frequent convulsions, full sputum, and Bruzinski positivity is an important sign.
3. Neonatal meningitis: often lacks typical symptoms and signs, sometimes similar to sepsis, fever is optional, even body temperature does not rise, crying is weak or high-profile, vomiting, refusal to eat, irregular breathing, cyanosis, jaundice, Drowsiness, local or systemic occult convulsions, physical examination showed that the anterior sputum was full, neck resistance, and there were few other meningeal irritation signs. Sometimes only the lumbar puncture examination of cerebrospinal fluid can confirm the diagnosis. Some sick children are detected until autopsy.
Examine
Examination of pediatric haemophilic influenza bacillus meningitis
1. Cerebrospinal fluid: Cerebrospinal fluid is purulent, smear examination can be seen very short Gram-negative bacilli, some similar to cocci, if different forms of bacteria are found on the same smear, or long or round, or single or double is not easy to determine All of them should be suspected to be influenza bacilli. Except for -mimapoly morpha, other bacteria have no such polymorphism.
2. Antigen diagnosis: Rapid antigen diagnosis method for influenza type 6 bacteria, including CIE, LA, ELISA, etc., the minimum detectable concentration of PRP by CIE method is 5 ng% to 10 ng%, so 75% to 90% of influenza bacillus meningitis This method can be used to confirm the diagnosis. The LA method is also very sensitive, but it is easy to have false positives. The ELISA and radioimmunoassay methods are more sensitive, but all require certain equipment, which is difficult and time-consuming to promote. Should be X-ray, ECG, B-ultrasound and brain CT examination.
Diagnosis
Diagnosis and diagnosis of pediatric haemophilic influenza bacillus meningitis
According to the clinical characteristics, combined with epidemiological data, the characteristics of the newborn, infants, and the incidence of older children, plus the results of laboratory tests, can make a diagnosis.
Escherichia coli K100 and Haemophilus influenzae may have cross-reactive antigens, should be identified, and should be differentiated from meningitis caused by other pathogens.
