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MeningitisMeningitisMeningitisMeningitis
Dr. Michael A. Borg & Dr. Peter Zarb
Infection Control Dept
Mater Dei Hospital
Malta1
Clinical description
• Meningitis is a disease caused by the
inflammation of the meninges.
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• The inflammation is usually caused by an
infection of the cerebrospinal fluid (CSF)
surrounding the brain and spinal cord.
– Multivaried aetiology
Viral Meningitis
• Clinically compatible illness with no laboratory evidence of bacterial or fungal meningitis
• Most common type of meningitis
• Incubation period is about 3 to 6 days
• Usually mild and self limiting
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• Usually mild and self limiting
• Duration of the illness is approximately 7 to 10 days
• Infectious period can last several weeks after symptoms have resolved
• Seasonal pattern in some countries
– USA: late summer and early autumn.
Viral Meningitis
• Enterovirus is the commonest pathogen
– 50% of meningitis in children <3mth
• Enteroviruses are most often spread through direct contact with an infected person’s stool.
– Can also be spread through:
• direct or indirect contact with respiratory secretions (saliva,
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• direct or indirect contact with respiratory secretions (saliva, sputum, or nasal mucus) of an infected person.
• Other causative viruses
– herpes, influenza, rubella, echo, coxsackie, EBV, adenovirus
• Some viruses can be insect borne
- Arboviruses
Bacterial Meningitis - Organisms
• Newborns: Grp B Streps (GBS),
E. coli, Listeria
• Infants: Strep pneumoniae (pneumococcus)
N. meningitidis (meningococcus)
H. influenza H. influenza
• Adolescents: Pneumococcus,
Adults Meningococcus
• Elderly: Pneumococcus,
Meningococcus,
Listeria
Acute Meningococcaemia
• Neisseria meningitidis: esp serotype Grp B
• Endotoxin causes vascular damage vasodilatation, severe shock
• Severe complication:• Severe complication:
Waterhouse-Friderichsen syndrome: massive haemorrhage of adrenal glands secondary to sepsis: adrenal crisis-low B.P, shock, DIC, purpura, adreno-cortical insufficiency
Bacterial Meningitis
• Not spread by casual contact or by simply breathing
the air where a person with meningitis has been.
• Spread through the exchange of respiratory and
throat secretions (i.e., coughing, kissing).
• Droplet spread
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• Droplet spread
– Direct coughing within 1 metre of patient
– Contact with respiratory secretions
• Less contagious than common cold or influenza.
• Listeria is food borne
– esp pregnancy and immunocompromised
Bacterial Meningitis -
Pathogenesis
• Infection/colonisation of upper respiratory
tract
• Invasion of blood stream (bacteraemia)
• Seeding & inflammation of meninges
Meningitis: Clinical features
Newborn & Infants: non-specific
• Fever
• Irritability• Irritability
• Lethargy
• Poor feeding
• High pitched cry, bulging AF
• Convulsions, opisthotonus
Tumbler (glass) test
• Press the side of a clear glass firmly against the skin.
• Spots/rash may fade at • Spots/rash may fade at first.
• Keep checking
• Fever with spots/rash that do not fade under pressure indicative of meningococcaemia.
Purpura fulminans
• Acute, often fatal, thrombotic disorder resulting from coagulation in small blood vessels within the skin
• Rapidly leads to skin necrosis and disseminated intravascular coagulation
Bacterial Meningitis Management
• Medical emergency
• Early diagnosis essential
• Immediate optimum treatment
• Intensive supportive therapy• Intensive supportive therapy
• Rehabilitation
• Prophylaxis to family
• Notification to Public Health
Meningococcaemia –
poor prognosis markers
• Onset of petechiae within 12 hrs
• Absence of meningitis• Absence of meningitis
• Shock (BP 70 or less)
• Normal or low WCC
• Normal or low ESR
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• 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%• 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
Prophylaxis for HCWs
• ONLY required for meningococcal disease in the following circumstances:– performed mouth-to-mouth resuscitation
– had prolonged close face to face contact • e.g. intubation and tracheal suction or the patient coughed
into their face.• e.g. intubation and tracheal suction or the patient coughed
into their face.
– When a case has only been diagnosed after a period of hospitalisation and HCW stayed in room with patient for a period > 6 hours.
– HCW who have had only brief contact with the patient should NOT be offered prophylaxis
• potential hazards of antibiotic therapy – side effects, the encouragement of resistance and the eradication
of non-pathogenic protective organisms.
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