Understanding Meningitis

Question 1

Understanding Meningitis

Answer 1

 inflammation of the meninges
 The meninges are the 3 membranes which enclose the brain and spinal
cord
 Meningism refers to the signs and symptoms that accompany the
inflammation

Question 2

Causes – meningitis can be caused by a variety of microbial agents:

Answer 2

 Bacteria
 Viruses
 Fungi
 Protozoa

Question 3

People at risk

Answer 3

 Babies and young children
 Teenagers and young adults
 Elderly people
 People with a weak immune system – e.g. those with HIV and those having
chemotherapy

Question 4

How is meningitis acquired and spread?

Answer 4

 Often caused by organisms which colonise the back of the nose and throat
 Sometimes acquired during birth e.g. Group B streptococci
 Can be present in amniotic fluid – contaminated by organism and be passed through
to the baby
 Meningitis can be spread by close contact, coughing and sneezing

Question 5

Bacterial meningitis

Answer 5

 Usually more severe than viral meningitis
 High fatality rate unless treated immediately
 Even with antibiotic therapy, many sufferers are left with disorders, most commonly
hearing loss
 Endotoxin release initiates organ dysfunction and blood disturbances
 Blood leaks from capillaries causing a purple rash

Question 6

Meningitis and meningococcal septicaemia

Answer 6

 N. meningitidis causes both meningococcal meningitis and meningococcal
septicaemia (collectively meningococcal disease)
 Gram negative diplococci, various virulence factors
 Meningococci colonise the oropharynx in some healthy people – these are the
carriers
 In these people, transition from carrier state to invasive disease occurs due to unknown factors
 Men A, B, C W and Y most commonly cause the disease (antigenic structure of the polysaccharide capsule – differentiated by the antigenic properties of the capsule)
 Bacteria can enter the bloodstream and cross the BBB to cause meningitis – bacteria can contain type 4 pili which attach to epithelial cells and pass through the brain side of the membrane
 May get meningitis – bacteria enters the bloodstream and reach the meninges and cause the meningitis
 Septicaemia results when bacteria enter the blood and multiply uncontrollably
 Patient may get one or the other or both
 MenW
 Cases of Men W are rising
 ST-11 is causing severe disease in healthy teenagers and young adults
 The symptoms it presents are different to bacterial and viral meningitis
 Severe respiratory problems and can cause GI problems

Question 7

Other causative bacteria

Answer 7

 Largely depends on age group as to which organism can affect the patient
 Streptococcus pneumoniae (gram positive and capsulated) can cause meningitic
disease in any age group, but especially children and elderly – sometimes spread by
an ear infection and can cause deafness
 Group B streptococci meningitic disease occurs primarily in babies – organism can be
acquired during birth which leads to symptoms developing within a few days
 Type B Haemophilus influenza (Hib) causes meningitis in infants and toddlers
 Meningitis caused by M. tuberculosis (can’t stain with gram stain, need to stain with
acid-fast) is rare in the UK, but should be considered when assessing patients from high risk areas

Question 8

Viral

Answer 8

 Most common form – more common than bacterial meningitis
 Illness is less severe and can just sleep it off
 Relatively benign illness and usually doesn’t need medical attention – may even go
unrecognised

Question 9

Usually presents as mild flu-like illness:

Answer 9

 Headache
 Fever
 General malaise

Question 10

In more severe cases:

Answer 10

 Neck stiffness
 Muscular/joint pain
 Nausea/vomiting
 Diarrhoea
 Photophobia
 Severe symptoms require hospital admission
 Usually make a full recovery, but rarely can be left with residual effects similar to meningitic diseases

Question 11

Fungal meningitis

Answer 11

 Causative fungi:
 Cryptococcus neoformans (most common) – associated with HIV infection as patient is usually immunocompromised
 Candida – in premature babies
 Coccidioides immitis – found common and usually in immunosuppression
 Histoplasma

Question 12

Cryptococcus neoformans

Answer 12

 Usually associated in patents with cell-mediated immune defects
 Organism travels from initial site of infection to the lungs, then invades the blood
stream
 Symptoms appear more gradually, over days or weeks

Question 13

Symptoms may include:

Answer 13

o Headache
o Fever
o Nausea/vomiting
o Stiff neck
o Dislike of bright lights
o Changes in mental state and hallucinations

Question 14

Early warning signs of meningitis

Answer 14

 Fever
 Headache
 Vomiting
 Muscle pain
 Fever with cold hands and feet
 Endotoxins produced can cause damage to the capillaries
 Toxins can make the tight junctions leaky and allow the blood to leak
 This will result in reduced blood volume and the heart in result will work harder
to pump blood around
 The body will restrict blood going to the skin and results in cold hands and feet
 Don’t wait for a rash!!!!

Question 15

Meningitis specific symptoms

Answer 15

• Rash
• stiff neck
• dislike of bright light
• confused/delirious
• seizures
  other: fever,vomiting,sleepy

Question 16

Meningococcal septicaemia

Answer 16

• aching limbs
• cold hands and feet
  a rash starts like pin prick spots and develops rapidly into purple bruising
• confused delirious
• fever
  vommiting
  difficulty breathing
• change in skin colour

Question 17

The tumbler test

Answer 17

 Someone who becomes unwell rapidly should be examined particularly carefully for
the meningococcal septicaemia rash
 People with meningococcal septicaemia may develop a rash of tiny pink prick spots
which can rapidly develop into purple bruising
 To identify the rash, press a glass tumbler against it and if the rash does not fade, it
be meningococcal septicaemia
 On dark skin, check the rash on lighter parts of the body e.g. finger tips, soles of feet

Question 18

Diagnosing meningitis in the lab

Answer 18

 Cerebrospinal fluid (CSF – a clear, colourless liquid that bathes the brain and spinal
cord providing shock absorption and support) may be taken and:
 Visually inspected – clear or turbid?
 A cell count performed
 Protein is analysed
 Glucose levels are analysed
 A centrifuged deposit is a) Gram stained and b) inoculated onto a range of media
to support the main pathogens
 Further specific tests performed
 Cerebrospinal fluid (CSF – a clear, colourless liquid that bathes the brain and spinal
cord providing shock absorption and support) may be taken and:
 Visually inspected – clear or turbid?
 A cell count performed
 Protein is analysed
 Glucose levels are analysed
 A centrifuged deposit is a) Gram stained and b) inoculated onto a range of media
to support the main pathogens
 Further specific tests performed
 Blood cultures