History taking and risk factor identification
The first stage of diagnosis consists of a thorough collection of epidemiological and clinical data. Special attention is paid to contact with sick individuals, visits to endemic regions, and winter-spring seasonality.
The risk group for severe disease includes:
- Patients with a burdened premorbid background (including a previously suffered infection).
- Unvaccinated individuals and those who have not received chemoprophylaxis.
- Patients after traumatic brain injury or neurosurgical interventions.
- Individuals with immunodeficient states (due to radiation, chemo-, or hormone therapy).
Clinical presentation of the mixed generalized form
The disease starts acutely: severe chills, fever, intense headache, nausea, and vomiting appear. Rapid progression of meningeal (and sometimes encephalitic) symptoms and potential impaired consciousness are characteristic.
Hemorrhagic exanthema is a key sign occurring within the first day (usually in 6–18 hours). The rash is asymmetrical, irregularly shaped, of various sizes, with central necrosis. Most often, it is localized on the distal parts of the legs and arms, buttocks, around large joints, and on the trunk. Hemorrhagic rash on mucous membranes is possible.
Severe complications can develop rapidly: infectious-toxic shock, cerebral edema, or acute renal failure.
Laboratory confirmation of diagnosis
Laboratory diagnosis includes a set of methods to detect the pathogen itself or its antigens:
- CSF analysis: reveals cyto-biochemical changes characteristic of purulent meningitis.
- Immunology and genetics: rapid latex agglutination tests (in CSF), countercurrent immunoelectrophoresis, and PCR (in CSF and serum).
- Bacteriology: microscopy and culture of blood and cerebrospinal fluid (detection of diplococci resembling Neisseria meningitidis).
- Serology: rising antibody titers in indirect hemagglutination assay (IHA) by the second week.
- Complete blood count: marked neutrophilic leukocytosis with a left shift and accelerated ESR.
Diagnosis formulation and management tactics
A detailed clinical diagnosis must reflect the clinical form, severity degree (assessed by the severity of intoxication, meningeal syndrome, hemodynamic status, and presence of complications), and the method of laboratory confirmation.
Management tactics depend on the severity of the condition, presence of shock or cerebral edema, and the sensitivity of the isolated N. meningitidis strain to antibiotics. Criteria for successful treatment include relief of intoxication, regression of neurological symptoms, stabilization of hemodynamics, and normalization (sanation) of the CSF.
Briefly: answers to topical questions
Which specific biochemical parameters of the CSF (protein, glucose, chlorides) change in purulent meningococcal meningitis?
In purulent meningococcal meningitis, protein and glucose concentrations in the cerebrospinal fluid change; data on changes in chloride levels are absent. Biochemical analysis of the CSF reveals the following characteristic shifts:
- Protein — elevation up to 2–8 g/L, accompanied by cellular-protein dissociation and a positive Pandy's test.
- Glucose — pronounced decrease in concentration.
- Lactate — elevated levels.
Which antibacterial drugs are the drugs of choice for treating meningococcal infection?
Drugs of choice and alternative agents for etiotropic antibacterial therapy of meningococcal infection according to sources:
- Chloramphenicol (levomycetin) — 80–100 mg/kg of body weight per day; in severe meningococcemia or threat of infectious-toxic shock, administration of levomycetin succinate is preferred.
- Ciprofloxacin — 0.8–1.2 g/day.
- Carbapenems (meropenem).
- Ampicillin.
- For primary purulent meningitis of unknown etiology, including meningococcal, third-generation cephalosporins are used: ceftriaxone 4 g/day intravenously.
For generalized forms of MI, sources also indicate: initiate etiotropic therapy immediately upon the first suspicion; a single dose of penicillin is administered immediately after the initial examination.
Class and exam questions
When does the rash appear in meningococcal infection and what does it look like?
The rash appears during the first day (usually 6–18 hours from the onset of the disease). It is hemorrhagic, asymmetrical, stellate (irregularly shaped), with areas of necrosis in the center.
What material should be collected for rapid diagnostics?
Cerebrospinal fluid (CSF) is used for rapid tests (e.g., latex agglutination) for meningococcal antigens.
What is characteristic of the complete blood count in this infection?
The complete blood count shows marked neutrophilic leukocytosis with a strong left shift and a significant acceleration of ESR.
What else to study on this topic
- Focus control measures: examination and isolation of contacts
- Specific prophylaxis: indications and target groups for vaccination
- Management tactics for meningococcal carriers
- Quarantine measures in organized groups
- Treatment of acute nasopharyngitis at home and in the hospital
Master the complete topic in the «Infectious Diseases» course
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