Meningitis causes bacterial Viral

MENINGITIS

CAUSES

• Bacterial

• Viral

• Fungal

Bacterial Meningitis - Organisms

• • Birth - 4 wks: GBS, E.coli

• 4 - 12 wks: GBS, E.coli, Pneumococcus Salmonella, Listeria, H. Influenza

• 3 mths - 3 yrs: Pneumococcus, Meningococcus

• H. Influenza

• 3 yrs+ adult: Pneumococcus, Meningococcus

Bacterial Meningitis - Pathogenesis

• Infection of upper respiratory tract

• Invasion of blood stream (bacteraemia)

• Seeding & inflammation of meninges

Meningitis: Clinical features

• Newborn & Infants: non-specific

• Fever

• Irritability

• Lethargy

• Poor feeding

• High pitched cry, bulging AF

• Convulsions, opisthotonus

Kernig’s sign

Brudzinski’s sign

Meningitis: older children

Acute Meningococcaemia

• Neisseria meningitidis: serotype Grp B commonest

• Endotoxin causes vascular damage vasodilatation, third spacing, severe shock

• Severe complication:

• Waterhouse-Friderichsen syndrome: massive haemorrhage of adrenal glands secondary to sepsis: adrenal crisis-low B.P, shock, DIC, purpura, adreno-cortical insufficiency

Septicaemia

Purpura fulminans

Clinical features

Clinical features

Clinical features

Clinical features

Tumbler (glass) test

DIAGNOSIS

• Hx & PE

• Investigations:

• FBC

• R/L/B

• CRP

• Coag

• Blood gas

• Glucose

Diagnosis

CSF FINDINGS

Bacterial Meningitis Management

• •  Medical emergency

• •  Early diagnosis essential

• Immediate optimum treatment

• Intensive supportive therapy

• Rehabilitation

• Prophylaxis to family

• Notification to GP & Public Health

Bacterial Meningitis/Meningococcaemia Management

• ABC

• PICU

• Fluid management: aggressive resuscitation

• Dexamethasone: only in Pneumococcal and HiB, given before antibiotics

• Inotropes: increasing aortic diastolic pressure and improving myocardial contractility

Antibiotics

• Less than 2 months of age:

• Ampicillin + Cefotaxime+/- Gentamicin

• Treat for 3 weeks (neonate)

• Over 2 months:

• Cefotaxime

• Treat for 7-10 days

Prophylaxis

• Rifampicin:

• Children 5mg/kg bd x 2/7

• Adults: 600 mg bd x 2/7

• Pregnant contact:

• Cefuroxime IM x 1 dose

• OR

• Just do T/S and await result

Meningitis - Complications

• Septic shock - DIC

• Cerebral oedema

• Seizures

• Arteritis/venous thrombosis

• Subdural effusions

• Hydrocephalus . Abscess . Brain damage

• Deafness

Meningococcaemia - poor prognosis

• • Onset of Petechiae within 12 hrs

• • Absence of meningitis

• • Shock (BP 70 or less)

• • Normal or low WCC

• • Normal or low ESR

Subdural Effusion

• Failure of temp to show progressive reduction after 72 hours

• Persistent positive spinal cultures after 72 hr

• Occurrence of focal/ persistent convulsions

• Persistence/recurrence of vomiting

• Development of focal neurological signs

• Clinical deterioration after 72 hr especially ICP

Partially treated meningitis

• 50% cases prior antibiotic - alters the findings in bacterial meningitis -

• Accurate history vital

• CSF mainly lymphocytic [not usual polys]

• Can have normal glucose

• +ve cultures reduced by 30%

• Gram stain reduced by 20%

Viral meningitis

• Most common infection of CNS especially in <1yr

• Causes: enterovirus (commonest, meningitis occurring in 50% of children <3mth ) herpes, influenza, rubella, echo, coxsackie, EBV, adenovirus

• Mononuclear lymphocytes in CSF

• Symptomatic treatment. Complications associated with encephalitis and ICP

TB Meningitis

• Usually insidious: difficult to diagnose in early stages (fever 30%, URTI 20%)

• Rare in children in developed countries

• If untreated is usually fatal

• Meningitis usually occurs 3-6mths after primary infection

• 1 stage-lasts 1-2wk, fever malaise, headache

• 2 stage-+/- suddenly, meningeal signs

• 3 stage-worsening neurological condition, death

Mortality/Morbidity

• Bac meningitis: Overall mortality 5-10%

• Neonatal meningitis: 15-20%

• Older children: 3-10%

• Strep. pneumonia: 26-30%

• H. influenza type B: 7-10%

• N. meningitidis: 3.5-10%

• 30% neurological complications

• 4% Profound b/l hearing loss (sensorineural) in all bac meningitis

Mortality/Morbidity

• Viral meningoencephalitis: Enteroviral fewer complications

• Tuberculous meningitis: related to stage of disease

• Stage I-30% morbidity

• Stage II- 56%

• Stage III-94%

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