MENINGITISMeningococcal Meningitis

Dr.T.V.Rao MD

Dr.T.V.Rao MD 1

Introduction• Bacterial meningitis is an inflammation of

the leptomeninges, usually causing by bacterial infection.

• Bacterial meningitis may present acutely (symptoms evolving rapidly over 1-24 hours), sub acutely (symptoms evolving over 1-7days), or chronically (symptoms evolving over more than 1 week).

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In Meningitis Meninges are infected and Inflamed

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Etiology• Causative organisms vary with patient age, with

three bacteria accounting for over three-quarters

of all cases:

– Neisseria meningitidis (Meninococcus)– Haemophilus influenza (if very young and

unvaccinated)

– Streptococcus pneumoniae ( pneumococcus)

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Etiology◆ gram-negative Coccus

◆ Neisseria species ◆ 13 serogroups

◆ groups A, B, C

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Etiology• Other organisms

–Neonates and infants at age 2-3 months • Escherichia coli• B-hemolytic streptococci

• Staphylococcus aureus• Staphylococcus epidermidis• Listeria Monocytogenes

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Knowing about Meningococcal Disease

• Meningococcal disease is an acute, potentially severe illness caused by the bacterium Neisseria meningitidis. Illness believed to be meningococcal disease was first reported in the 16th century. The first definitive description of the disease was by Vieusseux in Switzerland in 1805. The bacterium was first identified in the spinal fluid of patients by Weichselbaum in 1887.

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Characteristics of N. meningitides• N. meningitidis, or Meninococcus, is an

aerobic, gram-negative diplodocus, closely related to N. gonorrhea, and to several nonpathogenic Neisseria species, such as N. lactamica. The outer membrane contains several protein structures that enable the bacteria to interact with the host cells as well as perform other functions.

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Transmission of Meninococcus

• Transmission• Primary mode is

by respiratory droplet spread or by direct contact.

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Pathogenicity • Meningococci are transmitted by droplet

aerosol or secretions from the nasopharynx of colonized persons. The bacteria attach to and multiply on the mucosal cells of the nasopharynx. In a small proportion (less than 1%) of colonized persons, the organism penetrates the mucosal cells and enters the bloodstream

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Pathogenesis• A offending bacterium from blood invades the

leptomeninges. • Bacterial toxics and Inflammatory mediators are

released.– Bacterial toxics

• Lipopolysaccharide, LPS• Teichoic acid• Peptidoglycan

– Inflammatory mediators• Tumor necrosis factor, TNF• Interleukin-1, IL-1• Prostaglandin E2, PGE2

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Pathogenesis• The outer membrane is surrounded by a

polysaccharide capsule that is necessary for pathogenicity because it helps the bacteria resist phagocytosis and complement-mediated lysis. The outer membrane proteins and the capsular polysaccharide make up the main surface antigens of the organism.

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Serotyping of Meninococcus • Meningococci are

classified by using serologic methods based on the structure of the polysaccharide capsule. Thirteen antigenically and chemically distinct polysaccharide capsules have been described.

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Different Serotypes and Epidemiology

• Almost all invasive disease is caused by one of five serogroups: A, B, C, Y, and W-135. The relative importance of each serogroups depends on geographic location, as well as other factors, such as age. For instance, serogroups A is a major cause of disease in sub-Saharan Africa but is rarely isolated in the United States.

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Systemic Spread of Meningococcal Infections

• The bacteria spread by way of the blood to many organs. In about 50% of bacteremia persons, the organism crosses the blood–brain barrier into the cerebrospinal fluid and causes purulent meningitis. An antecedent upper respiratory infection may be a contributing factor

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N. meningitidisHabitat: human nasopharynx (10-

25%)Similar to N. gonorrhea but less

exacting ?Can grow in BA, Chocolate agar

without selective media from CSF ?Id. CHO utilization: acid from glucose

& maltose. Dr.T.V.Rao MD 16

Meninges and spinal cord

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How patients present with Meningitis

•Meningitis ( inflammation of membrane covering brain) :•Headache •Photophobia (pain on looking at bright lights)•Stiff Neck•Convulsion•Vomiting•Septicemia (blood poisoning):•Rash (pinpricks + bruises)

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Clinical manifestation• Clinical manifestation of CNS

– Increased intracranial pressure• Headache• Projectile vomiting • Hypertension • Bradycardia • Bulging fontanel • Cranial sutures diastasis• Coma • Decerebrate rigidity • Cerebral hernia

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Clinical manifestation• Clinical manifestation of CNS

– Conscious disturbance• Drowsiness

• Clouding of consciousness • Coma• Psychiatric symptom

– Irritation – Dysphoria – dullness

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Dr.T.V.Rao MD

Clinical manifestations

Meningococcal meningitis

Septic period▲ an abrupt onset

▲ chills high fever

▲ Headache

▲ Petechias

▲ purpuras

▲Splenomegaly

Meningitic period

▲ intracranial pressure ▲ headache▲ vomiting ▲ restlessness▲ Stiff neck ▲ Kernig (+)▲ brudziski (+)

▲ gradually disappears,

▲ recovers to normal.

Prodromal period

Septic period Meningitic period

Convalescent period

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MENINGOCOCCAL INFECTION•Neisseria meningitidis: gram negative intracellular diplococci. •Groups A, B, C, W135 and Y.•Septicaemia, meningitis or bacteraemia.•Incubation period of 2 to 7 days.•Spread by droplets from asymptomatic carriers.•Case fatality of 10% (meningitis) and 20% (septicaemia).•Affects young children predominately

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Diagnosis• Isolation of the organism

from CSF or blood.

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Laboratory Findings• Other bacterial

test– Blood cultivation

– Film preparation of skin

petechiae and purpura

– Secretion culture of local

lesion

• Imageology examination

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PathogenicityMeningococcal meningitis, as a spread

from nasopharynx blood streammeninges in susceptible hosts.

Direct spread to meningesRash Adrenal hemorrhage (Waterhouse-

Friderchsen syndrome)

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Clinical manifestations

Meningococcal meningitis 26

Death from Waterhouse-Friderichsen syndrome

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Meningococcemia• Bloodstream infection• May occur with or without meningitis• Clinical findings• fever• petechial or purpuric rash• hypotension• multiorgan failure

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Clinical examination and Important Signs

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Diagnosing by Isolation and identification of Meninococcus

• Invasive meningococcal disease is typically diagnosed by isolation of N. meningitidis from a normally sterile site. However, sensitivity of bacterial culture may be low, particularly when performed after initiation of antibiotic therapy. A Gram stain of cerebrospinal fluid showing gram-negative diplococci strongly suggests meningococcal meningitis.

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Diagnosis• Diagnostic methods

– A careful evaluation of history – A careful evaluation of infant’s signs and

symptoms– A careful evaluation of information on

longitudinal changes in vital signs and laboratory indicators

• Rout examination of cerebrospinal fluid (CSF)

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Laboratory Findings• Especial examination of CSF

– Specific bacterial antigen test• Countercurrent immuno-electrophoresis• Latex agglutination• Immunoflorescent test

– Neisseria meningitidis (Meninococcus)

– Haemophilus influenza

– Streptococcus pneumoniae ( pneumococcus)

– Group B streptococcusDr.T.V.Rao MD 32

Lumbar puncture for CSF Examination

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INVESTIGATION

1.Blood culture (sp)2.Naso-pharyngeal

swab (both)3.Lumbar puncture

(mg)4.PCR serum (sp)5.PCR CSF (mg)6.Serology7.Bleb aspirate (sp)8.Skin scrapings (sp)

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Dr.T.V.Rao MD

Laboratory examination of CSF Cerebrospinal fluid examination (an important method to establish diagnosis) :

● pressure ● glucose ● WBC ● sodium ● protein chloride

Meningococcal meningitis

turbid

>1000×106/L

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Dr.T.V.Rao MD

Diagnosis with Combination of Factors

⒈ Epidemic season, age and epidemic situations.

⒉ Clinical features.

⒊Manifestations of severe form in sepsis and meningoencephalitis

⒋Increased leukocytes and polymorph nuclear leukocytes predominantly in peripheral blood.

⒌ Increased intracranial pressure and purulent changes in CSF.

⒍ Positive results in bacteriological examination.

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USUAL MANAGEMENT OF SUSPECTED CASE•Isolation•Released once they have had their antibiotic treatment for 48 hours•Intravenous Fluids•Often ill and pyrexia•Antibiotics•Cefotaxime (+ Ciprofloxacin or rifampicin). Will be given former for first 24-48 hours even if diagnosis uncertain.•Intensive care•Not unusual - unfortunately

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Epidemiology• Occurrence• Meningococcal disease occurs worldwide in

both endemic and epidemic form.• Reservoir• Humans are the only natural reservoir of

Meninococcus. As many as 10% of adolescents and adults are asymptomatic transient carriers of N. meningitidis, most strains of which are not pathogenic (i.e., strains that are not groupable).

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Antibiotic Therapy• Course of treatment

– 7 days for meningococcal infection

– 10～ 14 days for H influenza or S pneumoniae

infection

– More than 21 days for S aureus or E coli infection

– 14～ 21 days for other organisms

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PREVENTION: CHEMOPROPHYLAXIS

•Gets rid of bacteria from carriers (and cases)•Does not prevent infection•Given to those who, in 7 days before symptoms:

* Lived in same house* Kissed case on lips* Gave mouth to mouth resuscitation.

•Options: Ciprofloxacin, Rifampicin, Ceftriaxone.•Can be given up to 28 days after contact with case

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PREVENTION: VACCINATION IN RESPONSE TO CASE

•Available for groups A, C, W135 or Y.•Only used once group is confirmed•Given to same group who receive chemoprophylaxis.•Different vaccines used: conjugate group C or ACW135Y polysaccharide vaccines.•Limited immunity from polysaccharide vaccine: lifelong from conjugate vaccine• Now there is vaccine available for group B

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GROUP B VACCINES•Some countries (New Zealand, Cuba, Norway, and Chile) developed vaccines against local strains of B meningococci that use strain-specific outer membrane vesicle protein rather than capsular polysaccharide. •Polyvalent serogroups B vaccine that contains multiple bacterial surface proteins believed to be found in most meningococcal B strains responsible for the disease globally being developed Dr.T.V.Rao MD 42

Prognosis• Appropriate antibiotic therapy reduces the

mortality rate for bacterial meningitis in children, but mortality remain high.

• Overall mortality in the developed countries ranges between 5% and 30%.

• 50 percent of the survivors have some sequelae of the disease.

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Public Health Importance

Challenges: -Educating public-Timely reporting and records keeping-Updating information daily.-Alleviating public anxiety and concerns-Collaborating with health partners

Opportunities:-Educating public-Communication-Strengthening partnerships

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PUBLIC HEALTH RESPONSE: CASE DEFINITIONS

•CONFIRMED: antibiotics +/- vaccine•Clinical diagnosis of meningitis or septicaemia•Confirmed microbiologically as due to Neisseria meningitidis

•PROBABLE: antibiotics +/- vaccine•Clinical diagnosis of meningitis or septicaemia •Not microbiologically confirmed•Public Health Practitioner, in consultation with clinician, considers meningococcal infection most likely cause

•POSSIBLE: no antibiotics or vaccine•Public Health Practitioner, in consultation with clinician considers diagnoses other than meningococcal disease at least as likely

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• Programme Created by Dr.T.V.Rao MD for Medical and Health care workers in the

Developing World • Email

• doctortvrao@gmail.com

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