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

Meningitis: older children

Kernig’s sign

Brudzinski’s sign

Septicaemia

Rash

• Blotchy red rash that

doesn't fade or

change colour upon

pressurepressure

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

Diagnosis

CSF findings

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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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