Clinical Syndromes - Neisseria meningitides

Clinical Syndromes

N. meningitidis causes the following conditions: (a) meningitis,(b) meningococcemia, and (c) other syndromes.

◗ Meningitis

Meningococcal meningitis caused by N. meningitidis is most common in children and young adults. It is a febrile illness of short duration characterized by headache and stiff neck. Lethargy or drowsiness is frequent. Confusion, agitated delir-ium, and stupor are rarer. Mental obtundation, stupor, and coma due to increased intracranial pressure are some of the noted complications at the end stage of the disease.

Prognosis of meningitis is good, and the patients recover completely on immediate treatment with appropriate antimi-crobial therapy. However, prognosis is bad in comatose patients and in patients with local neurological findings.

◗ Meningococcemia

Meningococcemia with or without meningitis is a life-threatening condition. The condition presents as an acute fever with pete-chial rash. Small petechial rashes are continuously found on the trunk and lower extremities; subsequently the rashes may coalesce to form large hemorrhagic lesions.

Waterhouse–Friderichsen syndrome is an overwhelming sys-temic infection caused by N. meningitidis. This condition is characterized by severe disseminated intravascular coagula-tion, shock, and multisystem failure including destruction of adrenal glands. The condition, associated with circulatory collapse with intravascular coagulation, is invariably fatal. It is most commonly seen in persons suffering from deficiency of C5–C9 components of the complement. The vascular damage seen in this condition is caused primarily by the action of LOS endotoxin present in the meningococci.

◗ Other syndromes

Nonsuppurative arthritis, usually of the knee joint, is seen in approximately 10% of the patients with meningococcal dis-ease. This condition is observed within the first 48 hours of treatment and is believed to be immunologically mediated.

Recurrent meningococcal meningitis is another condi-tion which is associated with hereditary deficiency of various components of complement system.

Other conditions include meningococcal pneumonia (which probably results from the aspiration of the organisms), septic arthritis, purulent pericarditis, and endophthalmitis.