Meningitis%20-%20acute,%20bacterial Signs and Symptoms

• Meningitis is the infection of the meninges and subarachnoid space that is usually caused by bacteria [eg Haemophilus influenzae type B (Hib), Neisseria meningitidis, Streptococcus pneumoniae, Listeria monocytogenes] and results in high mortality and morbidity throughout the world

• The introduction of conjugated vaccines against H influenzae type B, N meningitidis and S pneumoniae caused decline in the incidence of bacterial meningitis in children thus, majority of cases are now present in the adult population
• Causative agents depend on the age of the patient and predisposing factors (eg compromised immune system, liver disease, alcoholism, uncontrolled diabetes, pregnancy, living in dormitories/military barracks, jail)

Alternative Causes of Meningitis

• Spirochetes eg Treponema pallidum
• Mycobacteria eg Mycobacterium tuberculosis
• Fungi eg Cryptococcus, Coccidioides, Sporothrix
• Viruses eg herpes simplex virus (HSV), varicella zoster (VZV), cytomegalovirus (CMV), enterovirus
• Protozoa and helminths
• Malignancy eg leukemia, lymphoma

• Classic triad: Fever, neck stiffness and an altered level of consciousness is present in <50% of cases and some may have severe headache (especially in children) or any of the other symptoms:
  • Chills
  • Myalgia
  • Photophobia
  • Focal neurologic symptoms [eg cranial nerve palsies, ataxia, dilated/unequal and poorly reacting pupils (late sign)]
  • Nausea/vomiting
  • Seizures (late sign)
  • Some patients may present with petechial rash