Transcript Bacterial Meningitis

Presented by,
Afrah Abdul Wahid Ali
Ashutosh Wanchu
Lavina Loungani
Sophie Gorniewicz
Tahir Yahya
Case Study
 A 3 yr old girl was brought to the emergency room by
her parents because of fever and loss of appetite for the
past 24 hrs and difficulty in arousing her for the past 2
hrs.
 The developmental history had been normal since birth.
Her childhood immunization were current.
 She attended a day care center and had a history of
several episodes of presumed viral infections similar to
those of other children at the center.
Clinical Features
 Temperature was 39.5 C
 Pulse-130/min
 Respirations-24/min
 BP-110/60 mm Hg
Physical Examination
 Physical examination showed a well-developed and well-nourished
child of normal height and weight who was drowsy.
 When her neck was passively flexed, her legs also flexed (+ve
Brudzinski sign, suggesting irritation of meninges).
 Ophthalmoscopic examination showed no papilledema, indicating
that there had been no long-term increase in intracranial pressure.
 The remainder of her physical examination was normal.
Laboratory Findings
 CSF fluid was cloudy. Gram staining showed many
polymorphonuclear cells with gram negative diplococci
suggestive of neisseria meningitidis.
 White blood cell count – 25,000/µL ( markedly elevated), with
88% PMN forms and an absolute PMN count of 22,000/µL
(markedly elevated), 6% lymphocytes, and 6% monocytes.
 CSF protein was 100 mg/dL (elevated)
 Glucose was 15 mg/dL (low, termed hypoglycorrhachia)
 Cultures of blood and CSF grew serogroup B N.
MENINGITIDIS
What is meningitis
 Meningitis is a common name for infections (inflammation)
that take place in the meninges surrounding the brain and
spinal cord.
 One of the most serious forms of meningitis is
Meningococcal meningitis. It is caused by Neisseria
meningitidis.
 An infection with meningococcal bacteria causes a serious,
potentially fatal infection called meningococcal disease.You
may have heard it referred to as bacterial meningitis.
Meningococcal disease can also cause a very serious condition
called sepsis (blood poisoning).
Types of meningitis
 Aseptic meningitis: caused by viruses (e.g. mumps), SLE, and
some types of medications.
 Bacterial meningitis: caused by a bacterial infection.
Numerous microorganisms may cause bacterial meningitis:
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Neiseria meningitidis
Streptococcus pneumoniae
Listeria monocytogenes
Haemophilus influenzae (type B)
Mycobacterium tuberculosis
Group B Streptococci
Escherichia coli
Types of meningitis (cont.)
 Viral meningitis: caused by viruses (enterovirus).
 Tuberculous meningitis: caused by tuberculosis infection
due to Mycobacterium tuberculosis.
 Cryptococcal meningitis: caused by infection from a yeast
called Cryptococcus (found in soil and bird droppings). Often
associated with AIDS.
 Neoplastic meningitis: caused by the spread of solid
tumors to the brain or spinal cord.
 Syphilitic meningitis: due to infection with the bacterium
that causes syphilis
Epidemiology
 SOURCE & RESERVOIR:
 Man
 Subclinical infection
 carrier (they carry the bacteria in their nose and throat but
never become sick)
 MODES OF TRANSMISSION:
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Close contact with a person who is sick with the disease
Contact with carriers
Living in close quarters, such as college dormitories
Being in crowded situations for prolonged periods of time
Sharing drinking glasses, water bottles, or eating utensils
Kissing, sharing a cigarette
Epidemiology (cont.)
 INFECTIOUS MATERIAL:
 Nasopharyngeal secretions
 PEOPLE AT RISK:
 Neonates
 Children, teens, and young adults
 Elderly
 People who have a weakened immune system
 AIDS patients are at high risk for Tuberculous meningitis
Etiology
 Bacterial meningitis is due most often to hematogenous spread
of bacteria to the leptomeninges.
 It can also be seen after head trauma as skull fracture through
the sinuses.
 Local infections such as mastoiditis may also lead to meningitis.
 Surgery or CNS infection such as cranial epidural abscess may
lead to meningitis.
Etiology (cont.)
 Neonates: Group B Streptococci, Escheridia coli, Listeria
monocytogenes
 Infants: Neissera meningitidis, Haemophilus influenzae,
Streptococcus pneumoniae
 Children: N. meningitidis, S. pneumoniae
 Adults: S. pneumoniae, N. meningitidis, Mycobacteria,
Cryptococci
Pathogenesis
 Bacteria extend through the wall of blood vessels into the
subarachnoid space followed more slowly by neutrophils as
the blood brain barrier breaks down.
 The combination of bacteria and neutrophils in the
subarachnoid space irritates the underlying cerebral cortex
causing edema and increased intracranial pressure.
 If the meningitis is not treated neutrophils are followed by
lymphocytes and macrophages which with the bacteria, cause
irritation and degeneration of cranial nerves, production of
intimal fibrosis in arteries and fibrosis of the leptomeninges
which can lead to cortical infarcts and blockage of the
foramina of Lushcka and Magendie with hydrocephalus.
Pathogenesis
General Gross Description
 The brain in purulent meningitis has an opacity of the
leptomeninges by neutophils and bacteria. This is seen
over the convexity and the base.
 The brain is also usually swollen.
General Microscopic
Description
 In acute purulent meningitis, the subarachnoid space is filled
with neutrophils and bacteria with increasing numbers of
macrophages and lymphocytes over time.
 The underlying brain is usually protected by the pia so that
there is no intracerebral inflammation, however, the cortex
and white matter will show spongy change or vacuolization
due to edema.
 Infants more often show bacteria and neutrophils invading the
underlying parenchyma.
Symptoms
 Sudden high fever :
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The infection causes a high fever of about 130F or more which does
not get lower with a tepid bath or fever reducing medicine
Severe, persistent headache
Neck stiffness and pain that makes it difficult to touch your chin to
your chest is due to the swelling around the Meninges
Nausea and vomiting, sometimes along with diarrhea
Confusion and disorientation (acting "goofy") can progress to stupor,
coma, and death
Drowsiness or sluggishness
Eye pain or sensitivity to bright light
Muscle or joint pain or weakness
Symptoms
 Abnormal skin color
 Reddish or brownish skin rash or purple spots that do not turn
white when u press on them are a sign of sepsis. These may develop
because of inflammation and bleeding in small blood vessels
throughout the body, including those under the skin.
 Ice-cold hands and feet
 Numbness and tingling: Sepsis (also called blood poisoning) can
reduce the amount of blood that gets to the persons hand and feet,
causing coldness and numbness.
 Seizures: Swelling of brain tissue, increases pressure inside the skull,
and hampers blood flow, causing stroke symptoms, paralysis and
seizures.
Glass Test
 Press the side of the glass
tumbler against the rash
 If the rash does not disappear
then it is a symptom of
meningitis.
Symptoms In Children
Severe high fever
Feeding problems
Vomiting
Irritability
Seizures
High-pitched crying
Decreased appetite
The skin over the fontanelles (soft spots between the
skull bones) becomes taut, and the fontanelles may bulge.
 Infants may not develop a stiff neck
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Diagnosis
WHEN TO CALL THE DOCTOR:
 If a child 2 years old or younger has an unexplained fever and
the parent senses that the child is ill.
 If a child becomes increasingly irritable or unusually sleepy,
refuses to eat, vomits, has seizures, or develops a stiff neck.
 If an adult has fever, headache, skin rash, confusion,
unresponsiveness (stupor), seizures, and a stiff neck.
Diagnosis (cont.)
KERNIG SIGN:
 The Kernig sign is positive if pain in the lower back or
posterior thigh occurs when the knee is extended while the
patient is lying in the supine position and the hip is flexed at a
right angle.
Diagnosis (cont.)
BRUDZINSKI SIGN:
 The Brudzinski sign is positive if knee and hip flexion occurs
when the neck is flexed while the patient is in the supine
position.
Diagnosis (cont.)
NECK STIFFNESS:
 Nuchal rigidity is typically assessed with the patient lying
supine, and both hips and knees flexed.
INVESTIGATIONS DONE:
 Blood test
 Chest X-ray
 CSF analysis
 CT scan or MRI (MRI preferred over CT due to its
superiority in demonstrating areas of cerebral edema, ischemia,
and meningeal inflammation)
 Cultures of samples of CSF, blood, urine, mucus from the nose
and throat, and pus from skin infections.
Diagnosis – CT Scan
Diagnosis (cont.)
CSF ANALYSIS:
 A spinal tap (lumbar puncture) is performed. A thin needle is
inserted between L4/L5 to withdraw a sample of CSF.
 The sample of CSF is sent to a laboratory, where the bacteria
can be cultured and identified.
 3 tubes of CSF are collected
 One for chemistry analysis for glucose & protein levels and
cell count
 One for microbiology analysis for Gram stain, bacterial
culture…
 One for cytology analysis
 It will help doctors distinguish between the different type of
meningitis.
CONDITION
GLUCOSE
PROTEIN
CELLS
Bacterial meningitis
Low
High
High
(>300/mm³)
Viral meningitis
Normal
Normal or
high
Mononuclear
(<300/ mm³)
Tuberculous
meningitis
Low
High
Pleocytosis
(300/ mm³)
Fungal meningitis
Low
High
(<300/ mm³)
Diagnosis (cont.)
 Culture media used for bacterial culture of CSF are:
 5% sheep blood agar
 Enriched chocolate agar
 Enrichment broth (eg, thioglycolate)
 Culture plates should be incubated in an atmosphere
containing 5 to 10% CO2.
 Antimicrobial susceptibility testing should be performed on all
clinically relevant bacteria isolated from CSF, so that the
antibiotic therapy that was started immediately can be
adjusted if necessary.
Diagnosis (cont.)
 METHODS FOR DETECTING BACTERIA IN CSF:
 Gram staining
 Acridine orange stain
Fluorochrome stain (bacteria appear bright red)
 More sensitive than gram stain
 Reduction in the time of examination of CSF smear
 Requires fluorescence microscope
 Wayson stain
 Simple & sensitive stain for screening CSF smears for
bacteria
 Bacteria appear dark blue
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Diagnosis (cont.)
 Quellung procedure (Quellung capsular reaction)
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Used to confirm presence of S.pneumoniae,
N.meningitidis, or H.influenzae
Antisera specific for the capsular polysaccharides of each
of these 3 bacteria are mixed with separate portions of
clinical specimens.
Formation of Ag/Ab complexes on the surfaces of these
bacteria induces changes in the refractive indices of their
capsules.
The capsules appear clear & swollen.
Diagnosis (cont.)
 METHODS FOR DETECTING BACTERIAL ANTIGENS:
 CIE (counterimmunoelectrophoresis)
 COAG (coagglutination)
 LA (latex agglutination)
 OTHER METHODS USED:
 EIA (enzyme immunoassays)
 LAL Assay (limulus amebocyte lysate assay)
 GLC (gas-liquid chromatography)
 PCR (polymerase chain reaction)
Complications
If the disease is left untreated, the following manifestatations are seen:
 Increased spinal fluid pressure
 Myocarditis: inflammation of the heart
 Hydrocephalus (blockage of spinal fluid in brain)
 Mental retardation
 Deafness :Loss of hearing from infiltration of the 8th nerve
 Brain damage:Spread from the meninges to the brain is called
meningoencephalitis
 Severe diarrhea and vomiting
 Internal bleeding
 Low blood pressure
 Shock
 Death
Complications
 Waterhouse-Friderichsen syndrome
 Adrenal gland failure due to bleeding into the adrenal
gland.
 Symptoms include acute adrenal gland insufficiency and
profound shock. It is deadly if not treated immediately
Treatment
 Because bacterial meningitis is a medical emergency, it's
important to start the treatment as soon as it is diagnosed or
even suspected.
 Bacterial meningitis is treated with antibiotics. The doctor will
start intravenous (IV) antibiotics with a corticosteroid (eg,
Dexamethasone) to bring down the inflammation before all
the test results are even known. When the specific bacteria are
identified, he may decide to change antibiotics or not.
 In addition to antibiotics, it is important to replenish fluids lost
from fever, loss of appetite, sweating, vomiting and diarrhea.
Treatment (cont.)
 Some patients may need to stay in the hospital, depending on
the severity of the illness and the treatment needed.
 Complications can require additional treatment.
 Anticonvulsants (eg, Diazepam or Phenytoin) might be given
for seizures.
 Additional IV fluids in case of shock or low blood pressure.
 Supplemental oxygen or mechanical ventilation if the child
has difficulty breathing.
 All neonates should have a hearing test following their
recovery to screen for hearing impairment.
Microorganism
Recommended
therapy
Duration of
treatment
Streptococcus
pneumoniae
Penicillin G or Ampicillin
OR
Vancomycin + Thirdgeneration cephalosporin
(eg, ceftriaxone or
cefotaxime)
2 weeks
Neisseria
meningitidis
Penicillin G
OR
Third-generation
cephalosporin (eg,
ceftriaxone or cefotaxime)
7 days
Haemophilus
influenzae
Third-generation
cephalosporin (eg,
ceftriaxone or cefotaxime)
7 days
Listeria
monocytogenes
Ampicillin or Penicillin G
3 weeks
Escherichia coli
Third-generation
cephalosporin (eg,
ceftriaxone or cefotaxime)
21 days or 2 weeks
Group B
streptococci
Ampicillin or Penicillin G
14-21 days
Prognosis
 If treated immediately, most patients who have acute bacterial
meningitis recover fully.
 But when diagnosis or treatment is delayed, permanent brain
damage or death becomes more likely, especially in very young
children and older people.
 Some patients develop seizures that require lifelong treatment.
 Even with appropriate treatment, about 5-15% patients die
from bacterial meningitis.
 10-20% of patients who survive bacterial meningitis have brain
damage, hearing problems, or developmental difficulties
(especially in children).
Prevention
 Cases of bacterial meningitis should be reported to state
or local health authorities so that they can follow and
treat close contacts of patients and recognize outbreaks.
 Overseas travelers should check to see if meningococcal
vaccine is recommended for their destination. Travelers
should receive the vaccine at least 1 week before
departure, if possible.
Prevention (cont.)
Prevention (cont.)
IMMUNIZATION:
 Haemophilus influenzae type b (Hib) vaccine
 Part of the recommended immunization schedule in
children.
 3 doses given at 2, 4 and 6 months of age, a booster dose is
given at 12-15 months of age.
 Pneumococcal conjugate vaccine (PCV7)
 Recommended for children under 2-5 years old who are at
high risk of pneumococcal disease (weak immune system).
 4 doses given at 2, 4, 6 and 12-15 months of age.
Prevention (cont.)
 Pneumococcal polysaccharide vaccine (PPV)
 Recommended for adults >65 and children >2 years who
have long-term health problems.
 1 dose is given (under some circumstances a 2nd dose may
be given).
 Meningococcal conjugate vaccine (MCV4)
 Recommended for children from 11 to 18 years who
haven't yet been vaccinated, who are at high risk of bacterial
meningitis, for microbiologists, for overseas travelers.
 1 dose is given.
Prevention (cont.)
CHEMOPROPHYLAXIS:
 Rifampin is given to family members of an infected person to
reduce their risk of contracting the disease as H influenzae can
persist in the nasopharyngeal secretions even after a successful
treatment.
 Pregnant women should not take rifampin as it may harm the
fetus. They should be treated with single doses of ciprofloxacin,
azithromycin, or ceftriaxone.
Tuberculous meningitis
DEFINITION:
 Infection of the meninges caused by Mycobacterium
tuberculosis (acid-fast Gram-positive mycobacterium), the
bacteria that causes tuberculosis.
 It is the most severe form of tuberculosis.
 It is caused by the spread of Mycobacterium tuberculosis to
the brain, from another site in the body. Infection begins in the
lungs and may spread to the meninges by a variety of routes.
Tuberculous meningitis (cont.)
EPIDEMIOLOGY:
 In areas with much tuberculosis,
 tuberculous meningitis usually affects young children
 it develops after the primaty tuberculosis infection
 In areas with less tuberculosis,
 tuberculous meningitis tends to strike adults.
 it is due to reactivation of an old focus of tuberculosis that
had been dormant
Tuberculous meningitis (cont.)
RISK FACTORS:
 history of pulmonary tuberculosis
 excessive alcohol use
 AIDS
 other disorders that compromise the immune system
Tuberculous meningitis (cont.)
SYMTOMS: (usually begin gradually)
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Fever
Sluggishness
Loss of appetite
Severe headache
Nausea and vomiting
Stiff neck
Sensitivity to light (Photophobia)
Loss of consciousness
Tuberculous meningitis (cont.)
DIAGNOSIS:
 CSF analysis
 Chest radiography
 CT scan or MRI
 Sputum examination
 Sputum culture
 Tuberculin skin testing
Tuberculous meningitis (cont.)
TREATMENT:
 If tuberculous meningitis is seriously suspected, treatment
should start immediately.
 Start with 2 month intensive course of isoniazid, rifampin,
pyrazinamide, and ethambutol followed by 4 months of
isoniazid and rifampin.
 The use of the corticosteroid (eg, dexamethasone) improves
survival but probably does not prevent severe disability.
 The hydrocephalus (accumulation of CSF in the brain) may
require placement of a ventriculoperitoneal shunt.
Tuberculous meningitis (cont.)
COMPLICATIONS:
 Brain damage which may cause
 motor paralysis
 seizures
 mental impairment
 abnormal behavior
 Cerebral ischemia ( anterior circulation most commonly)
 Mesencephalic infarction
 Syringomyelia ( disorder in which a cyst or tubular cavity
forms within spinal cord)
Prognosis of TB meningitis
 Fatal if untreated
 It causes severe neurologic deficits or death in >50%
of cases
 Long-term follow up is necessary to detect
recurrences
Tuberculous meningitis (cont.)
PREVENTION:
 BCG vaccine (given at birth)
 PPD (Purified Protein Derivative) Tuberculin test determines if
someone has developed an immune response to M.
tuberculosis
 0.1mL injected immediately under the surface of the skin of
the forearm
 Test should be read between 48 and 72 hours after the
injection for induration (hardness)
 Classified as positive based on the diameter of the
induration
Bibliography
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http://www.cdc.gov/ncidod/DBMD/diseaseinfo/meningococcal_g.htm
http://www.umm.edu/altmed/articles/meningitis-000106.htm#Following%20Up
http://www.wrongdiagnosis.com/b/bacterial_meningitis/intro.htm
http://www.immunize.org/searchiac3/searchiac3.asp?zoom_cat=1&zoom_and=1&zoom_per_page=10&zoom_query=bacterial+meningitis
http://www.clevelandclinic.org/health/health-info/docs/3300/3384.asp?index=11039
http://www.dhpe.org/infect/Bacmeningitis.html
http://www.emedicine.com/PED/topic198.htm
http://www.nlm.nih.gov/medlineplus/ency/article/000680.htm
http://www.kidshealth.org/parent/infections/lung/meningitis.html
http://www.meningitisuk.org/about-meningitis/bacterial-meningitis/frequently-askedquestions.htm
http://www.meningitisuk.org/about-meningitis/bacterial-meningitis/frequently-askedquestions.htm
http://www.guideline.gov/summary/summary.aspx?ss=15&doc_id=5946&nbr=00391
5&string=bacterial+AND+meningitis
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