MENINGITIS - Disease Management

Meningitis is an inflammation of the leptomeninges and underlying subarachnoid cerebrospinal fluid (CSF). approximately 75% being subacute. Bacterial seeding usually occurs by hematogenous spread, once in the CSF, the bacteria flourishes. Bacterial cell wall components initiate a cascade of complement- and cytokine-mediated events that result in at least 3 critical events: increased permeability of the blood-brain barrier, cerebral edema, and presence of toxic mediators in the CSF. Bacterial exudates extend throughout the CSF, particularly to the basal cisterns, damaging cranial nerves, obliterating CSF pathways, and inducing vasculitis and thrombophlebitis.

Causes

• Neonates Group B or D streptococci, nongroup B streptococci, E. coli, and L monocytogenes
• Infants and children H. influenza, S. pneumonia, and N  meningitidis
• Adults-S. pneumonia, H. influenza, N. meningitides, Gram-negative bacilli, staphylococci, streptococci, and Listeria species.

Risk Factors

• Aged >60 years or <5 years or younger
• Sex: In neonates, the male-to-female ratio is 3:1.
• Race blacks
• Crowding
• Immunosuppressed patients
• Splenectomy and sickle cell disease
• Alcoholism, diabetes, and cirrhosis
• Contagious infection, bacterial endocarditis
• Dural defect
• Intravenous drug abuse Ventriculoperitoneal shunt
• Malignancy
• Thalassemia major
• Some cranial congenital deformities

signs and Symptoms

Classic symptoms

• Headache
• Nuchal rigidity (Signs of meningeal irritation)
• Fever and chills
• Prodromal upper respiratory tract infection (URTI) symptoms (viral and bacterial)
• Altered sensorium
• Photophobia
• Seizures
• Vomiting
• Focal neurologic symptoms

Symptoms in infants

• Fever
• Lethargy and/or change in the level of alertness
• Poor feeding and/or vomiting
• Respiratory distress, apnea, cyanosis

Symptoms of partially treated meningitis

• Seizures
• Fever
• Changes in the level of alertness or mental status

Symptoms of fungal meningitis

• Headache
• Low-grade fever
• Lethargy

Symptoms of tuberculous meningitis

• Fever
• Night sweats
• Malaise, with or without the headache
• Weight loss
• Meningismus

DIAGNOSIS

Differential diagnosis

• Brain abscess
• Tremens encephalitis Herpes simplex
• Delirium
• Herpes simplex.
• Febrile seizures (Pediatrics)
• Neoplasms
• Herpes simplex encephalitis
• Meningitis and encephalitis subarachnoid hemorrhage

Investigations

• Complete blood count Serum electrolytes(CBC)
• Serum glucose
• Urinary electrolytes
• BUN and/or creatinine and liver profile
• Serum cryptococcal antigen
• Chest X-ray
• Serum test
• Cultures blood, nasopharynx, respiratory secretions, urine, and skin lesions.
• Latex agglutination or counter immunoelectrophoresis (CIE) of blood, urine, and CSF.
• Head CT scan with contrast or MRI

TREATMENT

Goal

identify the causative organism, treat patients with acute bacterial meningitis, assess whether a central nervous system (CNS) infection is present in those with suspected subacute or chronic meningitis.

Pharmacological Treatment

Antibiotics

• Infants <3 months: Ampcilline plus Cefotaxim, Gentamicin
• Children -3 months-12 yr: Cefotaxime, ceftriaxone,meropenem
• Adults-19-50yr: Cefotaxime, Ceftriaxone, ampicillin
• Adults> 50yr: Ampicillin plus cefotaxime or Ceftriaxone

S. pneumonia Pen MIC mcg/mL

• Penicillins
• Vancomycin
• Cephalosporins

Neisseria meningitidis

• Penicillins
• Chloramphenicol or cefoperazone/sulbactam
• Cephalosporins

Haemophilus influenza

• Cephalosporin8
• Chloramphenicol or cefoperazone/sulbactam
• Meropenem

Aseptic meningitis

Antivirals: Acyclovir

mycobacterium tuberculosis

• Isoniazid, rifampicin, pyrazinamide, ethambutol, streptomycin

PATIENT EDUCATION

• Regular follow-up
• Advise patients to report any sign of fever, sore throat, rash, or symptoms of meningitis.
• Complications
• Immediate: Septic shock, coma with loss of protective airway reflexes, seizures, cerebral edema, septic arthritis, pericardial effusion, and hemolytic anemia.
• Subdural effusions
• Delayed: Decreased hearing or deafness, other cranial nerve dysfunction, multiple seizures, focal paralysis, subdural effusions, hydrocephalus, intellectual deficits, ataxia, blindness, Waterhouse-Friderichsen syndrome, and peripheral gangrene

Prognosis

Pneumococcal meningitis has the highest rates of mortality and morbidity.