Transcript Additional causes of meningitis

Meningitis is clinical syndrome characterized by inflammation of the
meninges, that envelope the brain and spinal cord .
Types of meningitis
Most common bacteria causing
meningitis:
Streptococcus
pneumoniae (pneumococ
cus)
Neisseria meningitidis
(meningococcus)
Haemophilus
influenzae
(haemophilus)
Listeria
monocytogenes)
(listeria
•Extremes of age (< 5 or >60 years)
•Diabetes mellitus, chronic kidney failure,
adrenal insufficiency, hypoparathyroidism,
or cystic fibrosis.
•Compromised immune system like AIDS,
alcoholism ,use of immunosuppressant
drugs.
•Recent exposure to others with
meningitis, with or without
prophylaxis.
•Malignancy.
•Pregnancy.
Pathophysiology
 Most cases of meningitis are caused by infectious agents
that colonized in the host.
 What are the main sites of colonization ?
These infectious agents like bacteria
can arrive the CNS via 3 ways : Invasion of the bloodstream and subsequent
hematogenous seeding of the CNS.
 A retrograde neuronal (e.g., olfactory and peripheral
nerves) pathway .
 Direct contiguous spread.
 The migration pathways to meninges by:
Blood stream , Preformed tissue planes, window membranes
of
the labyrinths.
 Meningitis in newborn can be transmitted either
vertically e.g. pathogens that have colonized the maternal
intestinal or genital tract, or horizontally, via nursery
personnel or caregivers at home.
Invading to brain
-How bacteria invade the brain ??
•Factors that immortalize the infectious
process in meningitis are :•Replicating bacteria
•Increasing numbers of inflammatory cells
• cytokine-induced disruptions in membrane transport
and increased vascular and membrane permeability
All of these process make change in CSF cell count, pH,
lactate, protein, and glucose in patients.
Etiology and Epidemiology
 There are many microorganisms that can cause meningitis
including bacteria, viruses, fungi, parasites; also drugs may
be a cause (e.g., NSAIDs, metronidazole, and IV
immunoglobulin).
 Bacteria that cause meningitis include :
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Pachymeningitis.
Haemophilus influenzae meningitis.
Pneumococcal meningitis.
Streptococcus agalactiae meningitis
Meningococcal meningitis.
Listeria monocytogenes meningitis.
Gram-negative bacilli.
Staphylococcal meningitis: it colonized in the normal skin
flora. S epidermidis is the most common cause of meningitis in
patients with CNS shunt (ventriculoperitoneal).
 Additional causes of meningitis: Congenital malformation of
the stapedial footplate, Head and neck surgery, penetrating head
injury, comminuted skull fracture, and osteomyelitic erosion,
Skull fractures.
 H. influenzae meningitis primarily affects infants
younger than 2 years. S agalactiaemeningitis occurs
principally during the first 12 weeks of life but has also
been reported in adults, primarily affecting individuals
older than age 60 years. The overall case-fatality rate in
adults is 34%. Among the bacterial agents that cause
meningitis, S pneumoniae is associated with one of the
highest mortalities (19-26%).
How bacteria reach meninges
 Pachymeningitis reach the meninges by skull defect, or
an infection from paranasal sinuses.
 Pneumococcal meningitis: it is the most common
bacterial agent in meningitis associated with basilar skull
fracture and CSF leak.
 Listeria monocytogenes meningitis: it is widespread in
nature and a common food contaminant, most human
cases was food borne.
Prognosis
 Patients who presented with an impaired level of
consciousness or seizures, have increase risk of death
and neurologic sequelae.
 In bacterial meningitis , a score was set to predict
outcome including several variables. Including:
 Older age , Increased heart rate.
 Lower Glasgow Coma Scale score.
 Cranial nerve palsies.
 What is the most important complication? And what is the
percentage ?
 Bacterial meningitis is fatal in 1 in 10 cases and 1 of every 7
survivors left with impediment like defenses.
Diagnosis
physical
exam
certain
diagnostic
tests
Characteristic clinical signs and 
symptoms can be absent
•Blood cultures
•Imaging
•Spinal tap (lumbar puncture)
Blood cultures
 Blood samples are placed in a special dish to see if it grows
microorganisms, particularly bacteria
 limitation : Pretreatment with antibiotics decreases the yield.
Cranial Imaging
 (Normally computed tomography, CT) scans of the head
may show swelling or inflammation.
•
May lead to a substantial delay in the initiation of antibiotic
treatment, which leads to poor outcome.
Spinal tap (lumbar puncture)
This fluid is sent to the lab
and analyzed to determine
if there is an infection.
“We determine:”
1- WBC(leukocyte) count
2- protein concentration
3- glucose concentration
then we perform CSF
culture and Gram stain.
Is the procedure of taking fluid
from the spine (CSF) in the lower
back through a hollow needle.
Limitation : Pretreatment with antibiotics decreases
the yield.
Signs and symptoms
infants (<2years)
older than 2 years
Complications
 Advanced bacterial meningitis may cause brain damage
and death. 50% of patients may have a serious
complications within a week, however in 30% of survivors
long term sequlae are seen.
 Complications include hearing loss, cortical blindness,
other cranial nerve dysfunction, paralysis, muscular
hypertonia, ataxia, multiple seizures, mental motor
retardation, focal paralysis, subdural effusions,
hydrocephalus and cerebral atrophy.
New Biomarker
 The differentiation between acute bacterial and non
bacterial meningitis is challenging because they share
many similar clinical symptoms, such as fever and
headache.
 A new biomarker (Procalcitonin) has been studied for the
diagnosis of bacterial meningitis.
 Procalcitonin (PCT) is a 116-amino-acid protein that is
produced primarily by the C cells of the thyroid gland and
secreted from leukocytes in the peripheral blood.
 In healthy individuals, PCT is secreted at levels that are
below the detectable limit. However, serum PCT levels
increase markedly in patients suffering from bacterial
infections.
 Comparison of the serum and CSF PCT levels between
the BM and non-BM patients.
Gram stain of N.
meningitidis in CSF has
high specificity but the
sensitivity is
poor. Furthermore,
bacterial culture is timeconsuming.
 The results of the meta-analysis indicated that CSF PCT
and blood PCT were both effective biomarkers for BM
diagnosis. The diagnostic accuracy of elevated blood
PCT appeared to be superior to CSF PCT. We also found
that blood PCT was associated with a higher pooled
sensitivity and specificity when compared with CSF PCT.
ROC curves of the serum and
CSF PCT for the diagnosis of BM.
Management
 Delay in treatment has been
First:
we should start
treatment with
wide-spectrum
antibiotics while
confirmatory
tests
associated with a poorer
outcome.
After
identification of
the pathogen
antibiotic
therapy as
appropriate for
patient age and
condition
Rapid transport to the emergency department
(ED) because of the early severe complications.
Treatment
Vaccination
 Pneumococcal Vaccination.
 Hib Vaccination (Haemophilus influenzae type b (Hib)).
 Three types of Meningococcal Vaccines used:
 Meningococcal conjugate vaccine (MCV4).
 Meningococcal polysaccharide vaccine (MPSV4) .
 Serogroup B Meningococcal B.
 New vaccines were developed against Group A
Neisseria meningitidis :
 MenAfriVac 10 µg of purified Men A polysaccharide
antigen conjugated with tetanus toxoid (PsA-TT) per
dose . ( 1-29 years ).
 MenAfriVac 5 µg for use in infants and children (3–24
months).
Patient Education
 Meningitis may require education regarding the need for
prophylaxis. All contacts should be instructed to come to
the emergency department immediately at the first sign of
fever, sore throat, rash, or symptoms of meningitis.
 These steps can help prevent meningitis:
1. Wash your hands.
2. Practice good hygiene.
3. Stay healthy.
4. Cover your mouth.
5. If you're pregnant, take care with food.
Done by
Lina Wahbeh
Dania Al Shafeey
Maysoon Najdawi
Jud Mohammad
Lama Diab
Hadeel ma’ani