W2P2 Flashcards
Meningitis definition
Inflammatory disease of the leptomeninges, the tissues surrounding the brain and spinal cord
Meninges include: dura mater, arachnoid, pia mater
What are the categories of Meningitis
Bacterial Viral Fungal Mycobacterial Parasitic
all types can cause meningitis, but we’re going to be focusing on the BACTERIAL AND VIRAL meningitis
Modes of Acquiring Bacterial Meningitis
- Community-acquired
2. Healthcare-associated-Post neurosurgical
What are the Pathogens that cause Bacterial Meningitis in Ages less than 1 month
Think of GEL
Group B streptococcus [strep agalactiae]
Escherichia Coli
Listeria Monocytogenes
Less than 1 month olds get infections with MATERNAL stool organisms. The GEL pathogens are all ones that live in the stool
- this will determine which antibiotic you choose.
What are the Pathogens that cause Bacterial Meningitis in Ages 1- 23 months and 2-50 years old
Community acquired ones like:
steptococcus pneumoniae
Neisseria Meningitis
What are the Pathogens that cause Bacterial Meningitis in Ages greater than 50 years
S. pneumoniae
N. meningitidis
L. monocytogenes
Aerobic Gram negative bacilli
Neisseria Meningitis
- mortality
- Which serogroups do we have vaccines for?
- Which serogroup is the most common in NA?
Has a high mortality: 10-20%
Has many different serogroups, know that we have vaccines for: A,B,C W-135 and Y)
- Serogroup B is most common
- Monovalent vaccine against serogroup B now available.
Risk factors for getting Neisseria Meningitis
- Mode of transmission
Risk Factors:
- Terminal complement deficiencies
- Functional or anatomic asplenia (e.g. sickle cell)
- Household exposure to an infected person
Transmission- Droplets respiratory secretions/saliva
Nasal carriage – up to 10% of healthy individuals
Which type of bacterial meningitis has the highest mortality
Listeria Monocytogenes
Streptococcus Pneumoniae Meningitis
- Route of Transmission
- Risk factors
high mortality
- Droplets
Risk Factors Functional or anatomic asplenia (e.g. sickle cell) Multiple myeloma Hypogammaglobulinemia Alcoholism Chronic liver disease Chronic kidney disease Malignancy Diabetes mellitus Cochlear implants CSF leak (e.g. from basilar skull fracture)
People with functional or anatomic asplenia are at higher risk of
getting infected by encapsulated organisms
i.s. strep pneumoniae and neisseria
Haemophilus influenzae Meningitis
- prelavence
- risk group
- Mode of transmission
With vaccination since 1998, meningitis due to H. influenzae type b is rare
Accounts for less than 5% of meningitis cases
Occurs primarily in unimmunized or partially immunized children
Transmission-Droplets
Listeria monocytogenes Meningitis
- mode of transmission (examples*)
Not as common
we carry it in our stool
however this one is NOT associated with droplet transmission it is FECAL-ORAL transmission
Accounts for approximately 2-8% of meningitis cases
Acquisition-contaminated (stool) foods
- Coleslaw
- Raw vegetables
- Milk and cheese (especially unpasteurized)
- Processed meats
most people have been infected with this and it goes away on its own EXCEPT for people at risk (pregnant women and those at the extremes of ages)
Risk factors for getting Listeria monocytogenes Meningitis
Risk Factors: Neonates (up to 10% of cases) Adults 60 years Alcoholics Malignancy Immunosuppressed (e.g. transplants, corticosteroids) Diabetes mellitus Liver disease Chronic renal disease Conditions with iron overload Pregnant women (25% of all cases of listeriosis) Mortality 15-30%
Streptococcus agalactiae Meningitis
Also known as Group B Streptococcus
Most common cause of meningitis in neonates
Mortality rate-7% to 27%
Isolated from vaginal or rectal cultures of 15% to 35% of asymptomatic pregnant women
Screening of pregnant women at 35-37 weeks gestation
GBS positive pregnant women receive intrapartum antibiotics to decrease mother to child transmission
Screening and intrapartum abx: 3-fold decrease in transmission
Bacterial Meningitis Healthcare-associated pathogens
Aerobic gram negative bacilli, including Pseudomonas aeruginosa - 40% of cases
Staphylococcus
- Coagulase negative
- S. aureus
Propionibacterium acnes (Teenagers, acne prone skin)
What are the three viral groups that give you viral meningitis
- Herpes simplex (mostly HSV-2)
- most deadly - Enteroviruses
- most COMMON: 85-95% of viral meningitis
- Echoviruses and coxsackieviruses
- Person to person transmission
- Seasonality: summer and fall
3. Arboviruses (arthropod-borne viruses) Transmitted by arthropods (mosquitoes, ticks) West Nile St. Louis Eastern Equine Western Equine California
- all these can cause Enchephalitis
Parameningeal foci of infection
Brain abscess, subdural empyema, epidural abscess, sinusitis, mastoiditis, etc..
^ these things can rupture INTO the CNS, this is a form of SECONDARY meningitis.
Meningitis Clinical Manifestations in Children
Non-specific in infants Fever Poor feeding Vomiting Lethargy Irritability Bulging fontanelle (late finding) Seizures
Older children Fever Vomiting Headache with photophobia Neck stiffness
Meningitis Clinical Manifestations in Adults
Top THREE are most common* Fever Headache Neck stiffness (Meningismus) Altered mental status Brudzinski’s sign Kernig’s sign Jolt accentuation
Brudzinski’s sign
B for Brain
Also known as Nape-of-the-neck sign
Passive flexion of the neck results in flexion of the hips and knees
Sensitivity: 5%
Specificity: 95%
- sensitivity is low, so just because it you get a negative sign, does not mean you can rule it out
however specificity is high, so positive sign highly likely to be meningitis
positive sign: stretching the neck will cause them to RESIST you from lifting their neck
Kernig’s sign
K for Knee
Patient supine, with the thigh flexed on the abdomen and the knee flexed
Leg is then passively extended
In the presence of meningeal inflammation, the patient resists leg extension.
Sensitivity: 5%
Specificity: 95%
Jolt test
Jolt accentuation
Patient is asked to quickly move their head from side to side in horizontal plane
If meningeal irritation is present: headache gets worse
Sensitivity: 21-64%
Specificity: 43-82%
Meningitis with RASH suggests which bacterial pathogen
Rash suggests N. meningitidis -seen in 75% of cases
Rash can also be seen in pneumococcal and enteroviral meningitis
Meningitis with Cranial nerve findings and difficulty breathing is suggestive of
L. monocytogenes (rhombencephalitis)
Clinical Management of Meningitis
ABCs Level of consciousness-Possible intubation Circulation-blood pressure Blood cultures Lumbar puncture (LP) Empiric antibiotics
CT scan (before LP) should be
- done in the following:
- Immunocompromised
- History of CNS disease
- Focal neurologic deficit
- New-onset seizure
- Papilledema
- Abnormal level of consciousness
Bacterial Meningitis vs Viral Meningitis
Bacterial: HIGH PRESSURE
HIGHER cell count [WBC and neutrophils] (viral is high too but bacterial is like 5 times higher)
and thus also comes with HIGH INTRACRANIAL pressure, so you’ll need an Lumbar puncture to relieve the pressure
AND characteristic in BACTERIAL
you’ll see CNS/serum glucose less than 60%
in viral
- less WBC, less neutrophils
- protein is whatever
- glucose is normal
- gram stain is NEG cause it’s a virus
gram neg dipplococci Meningitis
Neisseria meningitis
Gram Negative coccobacilli Meningitis
Haemophilus Influenzae
Gram Positive cocci in pairs (diplococci)
Streptococcus pneumoniae
Group B streptococcus
Gram positive Rods in Meningitis
Listeria Monocytogenes
Empiric Treatment for Neonatals
- What are the usual organisms
Group B streptococcus
Gram negative enteric rods
Listeria monocytogenes
ABs:
Ampicillin IV + Cefotaxime IV
Empiric Treatment for Infant (1-3 months)
- What are the usual organisms
Group B streptococcus
Gram negative enteric rods
Listeria monocytogenes
Streptococcus pneumoniae
Treatment:
Ampicillin IV + Vancomycin IV
+
Cefotaxime or Ceftriaxone IV
Empiric Treatment for Infant Pediatric (> 3 months)
and adult up to 50 years
- Usual Organisms
Streptococcus pneumoniae
Neisseria meningitidis
Haemophilus influenzae (type B)
EMPIRIC antibiotics
Cefotaxime or Ceftriaxone IV
+
Vancomycin IV
