invasive meningoccal disease Flashcards
(48 cards)
what is meningitis
inflammation of the meninges (membranes) which cover the brain and spinal cord
what are the 3 layers of meninges
dura mater
arachnoid mater
pia mater
usual causes of meningitis
infection with
- bacteria
- viruses
- less common ones: fungi, protoza &other parasites
non infectious causes of meningitis
- medications eg antibiotics, NSAIDS
- cancers eg melanoma, lung cancer
- autoimmune diseases eg SLE, Behcets syndrome
differential diagnoses for acute bacterial meningitis
• Viral meningitis
• Fungal meningitis
• TB meningitis
• Drug-induced meningitis Loading…
• Sepsis from other causes
• Encephalitis – inflammation of the brain
• Brain abscess – collection of pus in the brain
• Subarachnoid haemorrhage
• Brain tumour
• HIV infection
what is invasive meningococcal disease
infection with NEISSERIA MENINGITIDIS
describe neisseria meningitidis
gram negative dipolococci
carried by 10-24% of population
humans are the only known reservoir
describe transmittion of neisseria meningitidis
by respiratory droplets/nano-pharyngeal secretions
usually requires either frequent or prolonged close contact
incubation period of neisseria meningitidis
2- 10 days
usually 3-4 days
2 main manifestations of neisseria meningitidis
meningitis - a localised infection of the meninges with ‘local’ symptoms
septicaemia - a systemic infection with widespread signs, and generalised organ damage
how many sero groups of neisseria mengitidis
12 sero groups based on the capsular polysaccharide
when is meningitis more prominently
winter
which is worse - bacterial or viral meningitis
viral
risk factors for invasive meningococcal disease
Extremes of age
• Immunocompromised (e.g. HIV) or immunosuppressed (e.g. chemotherapy)
• Asplenia/hyposplenia
• Cancer – people with leukaemia and lymphoma
• Sickle cell disease
• Organ dysfunction – e.g. liver or kidney disease
• Cranial anatomical defects
• Cochlear implants
• Contiguous infection - e.g. otitis media, sinusitis, mastoiditis, pneumonia
• Smokers
• Living in overcrowded households, college dormitories or military barracks
• People who have had contact with a case
• Travellers abroad to high risk area - increased risk of encountering the pathogen
classic symptoms of meningococcal meningitis
fever
stiff neck
headache
confusion
increased sensitivity to light
nausea and vomiting
babies symptoms of meningococcal meningitis
slow or inactive
irritable
vomiting
feeding poorly
bulging anterior fontanelle - soft spot of the skull
meningococcal septicaemia symptoms
- fever and chills
- fatigue
- vomiting
- cold hands & feet
- severe aches or pains in the muscles, joints, chest or abdomen
- rapid breathing
- diarrhoea
- nom blanching rash (petechiae)
- in later stage - a dark purple rash (purpura)
what happens if you press a glass against a petechiae rash
the rash does not fade if you press the side of a clear glass firmly against the skin
what can sepsis cause
Disseminated intravascular coagulation - the activation of coagulation pathways that results in formation of intravascular thrombi and depletion of platelets and coagulation facors
these clots cause arterial occlusionsleading to gangrene of extremities & auto amputations
natural history of disease
acute onset
fulminating infection - occurs quickly, escalates uickly
prolonged and persistent coccaemia (bloodstream infection)
surovioprs may have long term complications -eg deafness, amputations, seizures
what specimens do you take on hospital admission before initiating antibodies
blood sample for culture & PCR
CSK for microscopy, culture and PCR
for other localised infections - aspirate from sterile site for microscopy, culture and PCR
throat swab for culture
additional samples for enhanced national surveillance
why do you notify public health about the disease
To find out how the patient caught it
when do you notify
on suspicion
don’t wait for confirmation
what action can public health take
contract tracing
chemoprophylaxis
vaccination
alerting and informing close contacts and the public
