Meningococcal infection (А 39) Infectio meningococcica

Acute infection of respiratory tract, which is caused by meningococcous (Neisseria meningitidis) and clinically represents in the forms of nasopharyngitis, sepsis or meningitis

Etiology Neisseria meningitidis Gramnegative diplococcus (0,6-1,0 mkm) Intracellular location in the blood smear, combined in pairs, cofee-grains-like A, B, C, D, X, Y, Z serotypes of infectious agents

Neisseria meningitidis

The source of disease: patients with meningococcal nasopharyngitis carriers (1 case per 2000 carriers) patients with meningococcal nasopharyngitis patients with generalized forms of infection

Mechanism of transmission – air-drop Seasonal occurrence – February-April Most of the patients are children under 10 Morbidity is sporadic, sometimes epidemic Immunity is type-specific, steady

Pathogenesis Entrance gate - upper respiratory routes Local inflammatory process (nasopharyngitis) Overcoming of a protective barrier (meningococcaemia) Penetration of the agent through hematoencephalitic barrier, irritation of receptors of soft cerebral membrane of the brain and systems, forming cerebrospinal fluid Hypersecretion of cerebrospinal fluid Disorders of circulation of the blood in the brain vessels and membranes, delay of resorbtion of cerebrospinal fluid Swelling-edema of the brain hyperirritation of the brain’s membranes and radices of cerebrospinal nerves Production of endotoxin, damage of endothelium of the vessels (capillary toxicosis, hemorrhagic symptoms, IDS, ITS)

Anatomic pathology changes

Classification: I. Primarily localized forms: - meningococcal carrier state; - acute nasopharyngitis; II. Hematogenic generalized forms: - meningococcemia; - meningitis; - meningoencephalitis; III. Mixed forms (meningococcemia+meningitis); IV. Rare forms (endocarditis, arthritis, irideocyclitis, pneumonia). Complications: severe brain edema, infectious-toxic shock

Rashes peculiarities: haemorrhagic; localization on buttocks, thighs, shins, trunk; a lot of elements; different sizes of elements – from patechial to the spread hemorrhages; non correct form, often star-like; different coloring and brightness of elements; necrosis in place of considerable hemorrhages with formation of defects; often combination of hemorrhages with roseolla and papules.

Haemorrhagic scleritis in case of meningococcemia

Typical position of patient with meningococal infection

Symptom Meningococal meningitis Second festering meningitis Serous (viral) meningitis Toubercoulous meningitis Beginning Sudden Acute Acute, rarer gradual Gradual, rarer subacute Fever High Of Long Duration Headache Very severe It Is Expressed Severe at the beginning of illness It is acute expressed, attack like in half of patients Vomits Often, without nausea Often Often, at the beginning of disease Rarely, gradually becomes more frequent Rigidity of muscles of the back of head Moderate Grows gradually Symptom Kernic It is expressed at the beginning of illness Grows gradually, expressed anymore than rigidity of muscles of the back of head

Laboratory diagnostics 1. Revealing of infectious agent in smears from pharynx, blood, liquor - the material for stain should be taken without touching of mucous membrane of cheeks and tongue. Microscopy: gram-negative diplococci with intracellular localization 2. Serologic tests: in dynamic with interval 5-7 days 3. Express-diagnosis: immunofluorescent method.

Liquor in case of meningococcal meningitis

Treatment Generalized forms: immediate hospitalization antibiotics in large doses (benzylpenicilline 200 000 – 500 000 U/kg, levomycetini succinatis) corticosteroids dehydratation therapy (in case of meningitis) desintoxication treatment of disseminated intravessel coagulation (heparin, contrical, human plasma) Sanation of meningococcus carriers: antibiotics in common doses (ampicillini, levomycetini, rifampicini) local sanation (ultraviolet, ultrasonic) desensibilisation therapy

Antiepidemic measures against the source of infection: - revealing of patients with meningococcal meningitis and sepsis and their hospitalization; - patients with meningococcal nasopharyngitis should be hospitalize in infectious hospital or isolate at home; - isolation of patients till their clinical convalescence and negative bacteriological investigation;

Ant epidemic measures contact persons should be observed during 10 days with their thermometry every day, skin and throat examination and bacteriological test persons with rash and inflammatory changes in the throat should be isolated and observed in child's institutions apply 10-days quarantine sanation of carriers by antibiotics (ampicillin, erythromycin) and discharging after double bacteriological investigation.