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