it is about acute bacterial meningitis

3. DEMOGRAPHY AND
EPIDEMIOLOGY
The highest incidence is among neonates, who are
usually infected by bacteria found in the birth canal
at the time of parturition.
• Group B streptococci (Streptococcus agalactiae) account
for the majority of cases; other causes include Listeria
monocytogenes, E.coli, other Gram-negative bacilli, and
enterococci.
From age 1 to 23 months, the most common
organisms are Streptococcus pneumoniae and
Neisseria meningitidis

4. Children from the second to the fifth year used to
have a high rate of infection caused by Haemophilus
influenzae type b. However the wide use of protein-
polysaccharide conjugated vaccines has
dramatically reduced the incidence of this infection
From age 2 through 18, N. meningitidis is the most
common cause, accounting for more than one-half
of cases, followed by S. pneumoniae
In adults up to age 60, S. pneumoniae is most
common followed by N. meningitis
Over age 60, most cases are due to S. pneumoniae
and less often L. monocytogenes

5. Etiology - in Adults
S. pneumoniae 30-50%
N. meningitidis 10-35%
H. influenzae 1-3%
G -ve bacilli 1-10%
Listeria species 5%
Streptococci 5%
Staphylococci 5-15%

6. Predisposing factors
Most cases of meningitis occur when colonization
by potential pathogens is followed by mucosal
invasion of the nasopharynx
However, some patients develop disease by direct
extension of bacteria across a skull fracture in the
area of the cribriform plate
Other patients develop meningitis following
systemic bacteremia as with endocarditis or a
urinary tract infection or pneumonia
Other predisposing conditions include asplenia,
complement deficiency, corticosteroid excess, and
HIV infection

7. Etiology and epidemiology of meningitis
Lack of immunity ( IgM or igG anti capsular antibody ) to
specific pathogens with young age.
recent colonization with pathogenic bacteria .
Close contact with invasive disease ( respiratory tract
secration)
Crowding , poverty , black race , male .
Defect in complement (C5- C8 ) associated with recurrent
meningococcal infection .

8. Etiology and epidemiology of meningitis
ventricular-peritoneal shunts:
Coagulase negative staphylococci and
corynebacteria .
CSF leaks due to fracture cribriform palate or
paranasal sinus ( pneumococcal ).

9. Etiology and epidemiology of meningitis
Splenic disfunction (sickle cell anemia or
asplenia ) increased risk of
pneumococcal , H.influenza type b
,rarely meningococcal sepsis and
meningitis .
.
head trauma or neurosurgical
procedures ( staphylococci )

10. Immuno-suppressed patients with T-cell
defects (AIDS, and malygnancy) :
Cryptococcal and L.monocytogens.
Open neural tube defect :
Meningomyelocele and lombosacral
dermal sinus associated with
staphylococci -Aureus and gram –
negative
Etiology and epidemiology of
meningitis(con)

12. CLINICAL FEATURES
The overwhelming majority of patients with
bacterial meningitis have fever and headache
Most patients have high fevers, but a small
percentage have hypothermia
CNS symptoms
• Some patients will have significant photophobia
and/or clouding of the sensorium
• Changes in mentation and level of consciousness,
seizures, and focal neurologic signs tend to
appear later in the course of disease

13. CLINICAL FEATURES
Nuchal rigidity
• Passive or active flexion of the neck will usually
result in an inability to touch the chin to the chest
Tests to illustrate nuchal rigidity
• The Brudzinski sign refers to spontaneous flexion of
the hips during attempted passive flexion of the neck
• The Kernig sign refers to the inability or reluctance to
allow full extension of the knee when the hip is
flexed 90 degrees

14. CLINICAL FEATURES
Other findings
• Some infectious agents, particularly N.
meningitidis, can also cause characteristic skin
manifestations, petechiae and palpable purpura
• If meningitis is the sequela of an infection
elsewhere in the body, there may be features of
that infection still present at the time of diagnosis
of meningitis eg, otitis or sinusitis

17. Differential Dx
Viral - 40 % of meningitis
Fungal
Tuberculous
Spirochete
Chemical / Drug induced
Collagen Vascular Disease
Parameningeal infection: brain abscess,
epidural abscess
Subarachnoid hemorrhage
Neuroleptic Malignant Syndrome

18. LABORATORY FEATURES
Most often the WBC count is elevated with a shift
toward immature forms
Platelets may be reduced if disseminated
intravascular coagulation is present or in the face of
meningococcal bacteremia
Blood cultures are often positive, and can be very
useful in the event that CSF cannot be obtained
before the administration of antimicrobials
• At least one-half of patients with bacterial meningitis
have positive blood cultures, with the lowest yield being
obtained with meningococcus

19. LABORATORY FEATURES
CSF analysis – every patient with meningitis should have
CSF obtained unless the procedure is contraindicated
Chemistry and cytologic findings highly suggestive of
bacterial meningitis include a CSF glucose concentration
below 45 mg/dL, a protein concentration above 500
mg/dL, and a white blood cell count above 1000/mm3
A Gram stain should also be obtained
The Gram stain is positive in up to 10 percent of patients
with negative CSF cultures and in up to 80 percent of
those with positive cultures

20. Opening pressure>180 mmH2O
White blood cells10/ L to 10,000/ L; neutrophils
predominateRed blood cellsAbsent in nontraumatic
tapGlucose <2.2 mmol/L (<40 mg/dL)CSF/serum
glucose <0.4Protein>0.45 g/L (>45 mg/dL)
Gram's stainPositive in >60%CulturePositive in >80%
Latex agglutinationMay be positive in patients with
meningitis due to S. pneumoniae, N. meningitidis, H.
influenzae type b, E. coli, group B
streptococci Limulus lysatePositive in cases of gram-
negative meningitisPCRDetects bacterial DNA

21. Typical Cerebrospinal Fluid Findings in
Patients with Bacterial Meningitis
Cerebrospinal Fluid Parameter Typical Finding
Opening pressure 200-500 mm H2O
White blood cell count 1000-5000/mm3
(range <100 to >10,000)
Percentage of neutrophils ≥80%
Protein 100-500 mg/dL
Glucose ≤40 mg/dL
CSF-to-serum glucose ratio ≤0.4
Gram stain Positive in 60%-90%
Culture Positive in 70%-85%
Polymerase chain reaction Promising

22. DX Color Opening
Pressure
RBC WBC Gluc Prot Smear Cx
Viral Normal Normal
or
elevated
0 100-
1000
mostly
mono’s
45-85 Normal
or
elevated
Neg Neg
Funga
l
Normal
or
cloudy
Normal
or
elevated
0 100-
1000
mostly
mono’s
< 45 > 50 Fungal
smear
positive
+/-
TB Normal
or
cloudy
Elevated 0 100-
1000
mostly
mono’s
< 45 > 50 AFB
positive
+/-

23. Complications ofComplications of
MeningitisMeningitis
Young children:
1. Babyish behavior
2. Forgetting recently learned skills
3. Reverting to bed-wetting
4. Babyish behavior
One of the most common problems
resulting from meningitis is hearing
loss. Anyone who has had
meningitis should take a hearing test.

24. Older people:
1. Lethargy
2. Recurring headaches
3. Difficulty in concentration
4. Short-term memory loss
5. Clumsiness
6. Balance problems
7. Depression

25. Serious complicationsSerious complications
Other serious
complications can
include:
1. Brain damage
1. Epilepsy
2. Changes in eye sight

26. Vaccine for meningitis~~Vaccine for meningitis~~
There are vaccines against Hib and against some strains
of N. meningitidis and many types of Streptococcus
pneumoniae. The vaccinevaccine against haemophilus
influenze (Hib) has reduced Hib meningitis cases by 95) has reduced Hib meningitis cases by 95
percentpercent since 1985.
There are vaccines to prevent meningitis due to S.
pneumoniae. The pneumococcal polysaccharide
vaccine is recommendedrecommended for all persons over 65 yearspersons over 65 years
of ageof age and younger persons at least 2 years oldat least 2 years old with
certain chronic medical problems.

27. Treatment and prevention of bacterial
meningitis
Suspected bacterial meningitis is a medical
emergency and immediate diagnostic steps must be
taken to establish the specific cause
The mortality rate of untreated bacterial meningitis
approaches 100 percent and, even with optimal
therapy, there is a high failure rate
Empiric treatment should be begun as soon as the
diagnosis is suspected using bactericidal agent(s)
that achieve significant levels in the CSF

28. Use of bactericidal agents
Bactericidal therapy is generally necessary to cure
meningitis
Bacteriostatic drugs, such as clindamycin and
tetracycline, are inadequate for meningitis
Chloramphenicol is a bacteriostatic drug for most
enteric Gram negative rods; however, it is usually
bactericidal for H. influenzae, N. meningitidis, and
S. pneumoniae and has been extensively and
successfully used to treat meningitis caused by these
organisms

29. Choice of agent
Selected third generation cephalosporins such as
cefotaxime and ceftriaxone, have emerged as the
beta-lactams of choice in the empiric treatment of
meningitis
These drugs have potent activity against the major
pathogens of bacterial meningitis with the notable
exception of listeria
Ceftazidime, another third generation
cephalosporin, is much less active against
penicillin-resistant pneumococci than cefotaxime
and ceftriaxone

30. Treatment - Empiric
Ceftriaxone 2 gm IV q12h or Cefotaxime
2 gm IV q4-6h
plus Vancomycin 15 mg/kg q6h
If > 50 years, also add Ampicillin 2 gm IV
q4h (for Listeria)

31. THERAPY FOR SPECIFIC PATHOGENS
Streptococcus pneumoniae
• The conventional approach to the treatment of
pneumococcal meningitis was the administration of
penicillin alone for two weeks at a dose of four
million units intravenously every four hours
• Good results have also been obtained with third
generation cephalosporins
However, the problem of treating pneumococcal
meningitis has recently been compounded by the
widespread and increasingly common reports of
pneumococcal strains resistant to penicillin

32. Cefotaxime or ceftriaxone can be used if the MIC
for these drugs is less than 0.5 µg/mL
It is recommended that vancomycin (2 g/day)
should be given with cefotaxime or ceftriaxone in
the initial treatment of pneumococcal meningitis if
there has been beta-lactam resistance noted locally
Vancomycin should be continued if there is high
level penicillin resistance and an MIC >0.5 µg/mL
to third generation cephalosporins
If corticosteroids are given, rifampin should be
added as a third agent since it increases the efficacy
of the other two drugs
The usual duration of therapy is two weeks

33. Haemophilus influenzae
A third generation cephalosporin is the drug of choice
for H. influenzae meningitis
Patients with H. influenzae meningitis should be treated
for five to seven days
For adults, a dose of 2 g every six hours of cefotaxime
and 2 g every 12 hours of ceftriaxone is more than
adequate therapy
Pharyngeal colonization persists after curative therapy
and may require a short course of rifampin if there are
other children in the household at risk for invasive
Haemophilus infection
The recommended dose is 20 mg/kg per day (to a
maximum of 600 mg/day) for four days

34. Neisseria meningitidis
This infection is best treated with penicillin
Although there are scattered case reports of N.
meningitidis resistant to penicillin, such strains are still
very rare
A third-generation cephalosporin is an effective
alternative to penicillin for meningococcal meningitis
A five day duration of therapy is adequate
However, when penicillin is used, there may still be
pharyngeal colonization with the infecting strain. As a
result, the index patient may need to take rifampin, a
fluoroquinolone, or a cephalosporin

35. Listeria monocytogenes
Listeria has been traditionally treated with ampicillin
and gentamicin, as resistance to these drugs is quite rare
Ampicillin is given in typical meningitis doses (2 g
intravenously every four to six hours in adults) and
gentamicin is used for synergy
An alternative in penicillin-allergic patients is
trimethoprim-sulfamethoxazole (dose of 10/50 mg/kg
per day in two or three divided doses)
The usual duration of therapy is at least three weeks

36. Enteric Gram negative rods
Prior to the availability of third generation
cephalosporins, it was often necessary to instill an
aminoglycoside antibiotic such as gentamicin directly
into the cerebral ventricles
It is now possible to cure these infections with high
doses of third generation antibiotics
A repeat CSF sample should be obtained for culture two
to four days into therapy to help assess the efficacy of
treatment
The duration of therapy should be at least three weeks

37. PREVENTION OF MENINGITIS
Vaccines
A spectacular reduction in H. influenzae meningitis has
been associated with the near universal use of a vaccine
against this organism in developed countries since 1987
There has been a 94 percent reduction in H. influenzae
meningitis between 1987 and 1995
Pneumococcal vaccine administered to the chronically
ill and elderly is probably useful in reducing the overall
incidence of pneumococcal infections. However, its role
in the prevention of meningitis is as yet undetermined

38. Vaccines
Meningococcal vaccines are active against many
strains of N. meningitidis
However, the majority of meningococcal infections
in the United States are caused by type b
meningococcus for which there is no vaccine
Vaccines for other types (notably type a) are
recommended for travelers and American military
personnel to countries with epidemic meningitis
Immunization against meningococci is not
warranted as postexposure prophylaxis

39. Chemoprophylaxis
There is a role for chemoprophylaxis to prevent
spread of meningococcal and haemophilus
meningitis but not for pneumococcal disease
The use of antimicrobial therapy to eradicate
pharyngeal carriage of meningococci is widely
accepted to prevent development of disease in close
contacts and to eradicate pharyngeal carriage
Rifampin 600 mg PO every 12 h for a total of four
doses is recommended
Ciprofloxacin, in a single dose of 500 mg PO, is
equally effective and can be used in patients over
the age of 18

40. Role Of Steroids
The addition of antiinflammatory agents has been
attempted as an adjuvant in the treatment of
meningitis
Early administration of corticosteroids such as
dexamethasone for pediatric meningitis has shown
no survival advantage, but there is a reduction in the
incidence of severe neurologic complications and
deafness
A meta-analysis of five such studies in children
showed a relative risk of bilateral deafness of 4.1
and of late neurological sequelae of 3.9 in controls
compared to children treated with steroids

41. A second meta-analysis of trials of meningitis in
children evaluated the findings according to
organism
For H. influenzae type b meningitis, dexamethasone
therapy was associated with a significant reduction
in deafness
For pneumococcal meningitis, dexamethasone was
effective only if given early ; in this setting, there
was a significant reduction in hearing loss
Two days of therapy was as effective and less toxic
than longer courses of steroid administration
Dexamethasone as adjunctive therapy in bacterial meningitis. A
meta-analysis of randomized clinical trials since 1988. JAMA
1997; 278:925

42. There is no consensus regarding the utility of
corticosteroid therapy in adults
The Infectious Disease Society of America
considers adjuvant corticosteroids for meningitis to
be unsupported for routine use in adults but supports
them for H. influenzae infections in children
Guidelines for the use of systemic glucocorticoids in
the management of selected infections.
J Infect Dis 1992; 165:1

43. MORTALITY RATE AND LATE
SEQUELAE
The prognosis of meningitis is linked to age and the
presence of underlying disease
Bacterial meningitis accompanying advanced liver
disease, HIV infection, or organ transplantation is
likely to be associated with more morbidity and
mortality
In addition, the prognosis and complications differ
in children and adults

44. The mortality rates are lowest in children
A meta-analysis of prospectively enrolled cohorts of
children in developed countries showed a 4.8 percent
mortality from 1955 to 1993
The mortality rate varied by organism, ranging from
3.8% for H. influenzae to 7.5 percent for N. meningitidis
to 15.3% for S. pneumoniae
83.6 percent of the surviving children had apparently
complete recovery
The most common sequelae were
• Deafness – 10.5 percent.
• Bilateral severe or profound deafness – 5.1 percent.
• Mental retardation – 4.2 percent.
• Spasticity and/or paresis – 3.5 percent.
• Seizures – 4.2 percent.

45. Complications are more common in adults
A series of 86 adults with meningitis, for example,
showed a mortality rate of 18.6 percent with a
complication rate of 50 percent
The most common problems were:
• Cerebrovascular involvement – 15.1 percent.
• Cerebral edema – 14 percent.
• Hydrocephalus – 11.6 percent.
• Septic shock – 11.6 percent.
• Disseminated intravascular coagulation – 8.1 percent.
• Acute respiratory distress syndrome – 3.5 percent.
Spectrum of complications during bacterial meningitis
in adults. Results of a prospective clinical study.
Arch Neurol 1993; 50:575

46. A second review of bacterial meningitis in adults
from 1962 to 1988 found a mortality rate of 25
percent that did not vary during the 26 years of the
study
As in children, there was a higher rate of death due
to S. pneumoniae (37 percent) as compared to N.
meningitidis (13 percent) and listeria (10 percent)
Acute bacterial meningitis in adults.
N Engl J Med 1993; 328:21.

47. Selected Bedside Signs of
Meningitis
Bedside Test Description
• Nuchal
rigidity or neck
stiffness
• Inability to flex the head forward due to rigidity of the
neck muscles; however, nuchal rigidity is absent if
flexion of the neck is painful but there is full range of
motionI
• Kernig's sign •• Inability to flex the head forward due to rigidity of the
neck muscles; however, nuchal rigidity is Extension in the
knee is painful (leading to resistance) when the leg is
fully bent at both the hp and knee
• Brudzinski's
neck sign
• Lifting a patient's head causes involuntary lifting of
the legs

48. Chemoprophylaxis Regimens for
Meningococcal DiseaseAge Group Chemoprophylaxis Regimens
for Meningococcal Disease
Antibiotic Regimen for
Chemoprophylaxis
Infants aged 1 month or less Rifampin 5 mg/kg q12h for 2 days
Children and infants older than 1
month
Rifampin 10 mg/kg q12h for 2 days
Children less than 15 years of age Ceftriaxone 125 mg intramuscularly
once
Adults Ceftriaxone 250 mg intramuscularly
once
or
Ciprofloxacin 500 mg once*
or
Rifampin 600 mg PO BID for 2 days

50. THANK YOU!
QUESTIONS?
Even my family hasEven my family has
stopped listeningstopped listening
to me!to me!
Love isLove is
unconditional withunconditional with
NoraNora

51. Age-Specific Incidence of Meningococcal
Disease, US, 2006
Nabb JN, et al, MMWR. 2008;55:1-94.

52. A 9-month-old Baby in Septic Shock with
Purpuric Neisseria meningitidis Skin Lesions
by D. Scott Smith, MD, taken at Stanford University Hospital.