MENINGITIS-BACTERIAL
Bacterial meningitis is a medical emergency
Untreated, its mortality can approach 100%
Untreated, its mortality can approach 100%
ETIOLOGY
- Streptococcus pneumonia(Common in Skull fracture, asplenism, HIV, and cochlear implants)
- Neisseria meningitidis
- Haemophilus influenza type B
The less common pathogens
- Escherichia coli
- Listeria monocytogenes(in neonates)
- Group A streptococci
- Staphylococcal species(Penetrating head trauma/ neurosurgery)
DIAGNOSIS
CLINICAL SIGNS
Nonspecific signs
- Tachycardia/ Fever
- Poor feeding/ Irritability/ Lethargy
- Vomiting
- Shock/ disseminated intravascular coagulation
- Purpuric rash
- Coma
Classical signs
- Nuchal rigidity
- Bulging fontanelle
- Photophobia,
- Positive Kernig’s
- Brudzinski’s sign (in children > 12months)
- Seizures( in 20–30%)
- Reduced level of consciousness.
INVESTIGATIONS
- Lumbar Puncture
LP may be delayed until these contraindications
But administration of antibiotics should not be delayed
CSF Investigations
- Gram Stain
- Culture
- Polymerase chain reaction (PCR)(may be positive despite pre-treatment with antibiotics)
- CSF lactate may be elevated
Other Investigations
- Full blood count
- Coagulation studies
- Serum glucose
- Blood cultures-(40% -60% positivity)
- CRP / Procalcitonin( Helps distinguish viral and bacterial meningitis)
Imaging.
- Computed tomography (CT) of the head
Indications - Increased intracranial pressure
- Deteriorating neurological function
- Immunocompromise
- History of neurosurgical procedures,
LUMBAR PUNCTURE/ CSF ANALYSIS
Contraindications
- Raised intracranial pressure
- Prolonged seizures
- Focal neurological signs
- Coagulation disorders
- Cardiorespiratory instability
- Localised infection at the site of lumbar puncture
CSF Investigations
- Microscopy
- Gram staining
- Culture
- CSF protein, and glucose levels.
Characteristics of Bacterial Meningitis
- CSF white cell count >1000 cells/mm3
- Majority of white cells are polymorphonuclear (PMNs).
- CSF protein is elevated (100–200 mg/dL)
- Glucose low (CSF to serum ratio <0.4)
Characteristics of partially treated meningitis
- Have higher glucose
- Lower protein level
- CSF cell count and absolute PMN count are not significantly affected
MANAGEMENT
Antibiotics
- Check local resistance patterns of pathogens.
- Antibiotics should be administered parenterally, IV Preferred. if not possible IM/ IO.
- Third-generation cephalosporin(such as ceftriaxone or cefotaxime) with vancomycin
- Listeria monocytogenes (child <3 months of age/ immunocompromised) add benzylpenicillin
Duration of antibiotics– Discuss with Microbiologist
- Commonly 7-day treatment course for Hib or N. meningitides
- 10–14-day course for S. pneumonia
Steroids.
- Dexamethasone(0.15mg/kg/dose, 4 times a day) before or up to 12 hours after the first dose of antibiotics for 2 to 4 days
Chemoprophylaxis.
- Close contacts should receive (ceftriaxone or rifampicin, or ciprofloxacin),
- Contacts of Hib should receive ceftriaxone or rifampicin
- Unvaccinated children <5 years of age should be vaccinated against H. influenza immediately.
Hearing test as outpatient follow up