Characteristics of meningococcal disease

The two major clinical forms of meningococcal disease are meningitis and septicaemia. Most patients will have a mixed presentation. A minority will have pure septicaemia and it is these patients who carry the worst prognosis and maximum effort must be made to identify them early¹². There are important differences in the pathophysiology of meningitis and septicaemia which underlie the clinical presentation and management of the two main forms of the condition (see pathophysiology).

Disease pathway

Clinical features of severe disease

The diagram above illustrates the main causes of death from MD. In the majority of patients, one disease process predominates. Patients presenting with mixed disease will also tend, as the disease worsens, to become either profoundly septicaemic or profoundly meningitic. A few will have combined severe septicaemia with shock and severe meningitis with raised intracranial pressure and these need expert management. Patients presenting with septic shock without meningitis carry the worst prognosis^{8 13}. Although a few patients with meningitis will die from raised intracranial pressure, most deaths from MD result from shock and multi-organ failure¹⁴.