Invasive Bacterial Diseases: The Basics

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Invasive Bacterial DiseasesThe Basics
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What are Invasive Bacterial Diseases ?

• Invasive bacterial diseases include
• Neisseria Meningitidis
• Haemophilus Influenzae
• Streptococcus Pneumoniae
• Group B Streptococcus
• Group A Streptococcus

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Sterile Site

• Blood
• Cerebrospinal fluid
• Pleural fluid
• Peritoneal fluid
• Pericardial fluid
• Surgical aspirate, bone, or joint fluid
• Amniotic fluid
• Surgically obtained tissue

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Non-Sterile Site

• Normal flora
• Respiratory Tract
• Ear, Eye, Mouth
• Skin ( Wound Abscess)
• Urine (Including Mid-Stream)
• Feces

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Reporting

• To the local health department in the patients
• county of residence within 24 hours of
• diagnosis
• Haemophilus influenzae, Invasive Disease
• Meningococcal Disease, Invasive (Neisseria
  meningitidis)

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Reporting

• To the local health department in the patients
• county of residence within 1 week of
• diagnosis
• Streptococcal Disease, Group A Invasive and/or
  Streptococcal Toxic Shock Syndrome (S. pyogenes)
• Streptococcal Disease, Invasive Group B
• Streptococcus pneumoniae, invasive disease
  --include antibiotic susceptibility patterns

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What is Colonization ?

• Presence of an agent in a host without
• causing a specific immune response or
• infection.
• Asymptomatic colonization
• Carrier State

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• Carrier State
• Appearance of an organism of relatively high
• pathogenicity in the normal flora without
• causing disease.
• Examples
• 5 to 20 of the general population carry the
  meningococcal bacteria in the nose and throat in
  a relatively harmless state.

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• Carrier State
• Examples
• Group B Strep is a bacterium found in the lower
  intestine of healthy adults and also in the
  vagina of approximately 10-33 of all healthy
  adult women.
• One of every four or five pregnant women carries
  GBS in the rectum or vagina without becoming ill.
• Nasopharyngeal carriage with encapsulated type b
  strains
• for H. Flu ranges from 3-5.
• As high as 50 in "closed" populations of young
  children, such as child care centers.CDC

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Invasive Bacterial Diseases Pathogenesis

• Colonization of the Nose or throat, e.g.
• Meningococcus
• H. Influenza
• S Pneumoniae
• Group A Strep
• Group B Strep

Invasion into the bloodstream (bacteremia)
Solid organ Abscess
Pericardial fluid Pericarditis
Seeding of distant sites
Cerebrospinal fluid Meningitis
Bone Osteomyelitis
Synovial fluid Septic arthritis
Pleural fluid Septic pleural effusion
CDC
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Bacteremia

• Bacteremia is an invasion of the
• bloodstream by bacteria.
• May cause no symptoms and resolve without
  treatment, or
• May produce fever and other symptoms of infection
  including septic shock.

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Meningitis

• Meningitis is an illness in which there is
• inflammation of the tissues that cover the brain
• and spinal cord.
• Bacterial Meningitis
• Meningitis with laboratory evidence of positive
  bacterial
• cultures from normally sterile site. CSF
  Pleocytosis gt 5 WBC
• Viral Meningitis
• Meningitis with no laboratory evidence of
  bacterial or fungal
• Culture from CSF. CSF Pleocytosis gt 5 WBC

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Meningitis

Bacterial
Viral
Severe
Less Severe
Quite severe and may result in brain damage,
hearing loss, or learning disability
Resolves without specific treatment
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Serogrouping / Serotyping

• Meningococcal Diseases Serogrouping
• H. Influnezae Serotyping - H. Flu Serotype b
  (Hib)
• Strep Pneumoniae Serotyping (Capsular)
• Importance
• Determine if circulating strains are vaccine
  preventable, and
• Assist with outbreak management, if necessary.

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• Questions