Diagnosis of meningococcal infection
In typical cases, diagnosing meningococcal infection is straightforward. Meningococcal infection is characterized by an acute onset, high fever, headache, vomiting, hyperesthesia, meningeal irritation symptoms, and a hemorrhagic stellate rash.
A lumbar puncture is crucial in diagnosing meningococcal meningitis. However, the fluid may be clear or slightly opalescent, with a pleocytosis of 50 to 200 cells, with a predominance of lymphocytes. These are the so-called serous forms of meningococcal meningitis, which usually occur when treatment is initiated early. In these cases, antibiotic therapy interrupts the process at the serous stage.
The most important tests are bacteriological examination of cerebrospinal fluid and blood smears (thick blood film) for the presence of meningococci. Among serological methods, the most sensitive are the RPGA and the counter immunoelectroosmophoresis test. These tests are highly sensitive and can detect trace levels of specific antibodies and minimal concentrations of meningococcal toxin in the blood of patients.
Differential diagnosis of meningococcal infection
Meningococcal infection, which occurs as meningococcemia, should be differentiated from infectious diseases accompanied by a rash (measles, scarlet fever, yersiniosis), hemorrhagic vasculitis, sepsis, thrombopenic conditions, etc.
Forms of the disease with damage to the central nervous system are differentiated from toxic influenza, other acute respiratory viral infections that occur with meningeal and encephalitic symptoms, as well as other infectious diseases (severe dysentery, salmonellosis, typhoid fever, etc.), accompanied by meningeal symptoms.