In addition to the immediate threat to life, they can lead to permanent sequelae involving reduced mental and physical performance. Therefore, in any case of suspected CNS infection, immediate medical intervention and, if the diagnosis is confirmed, prompt treatment and hospitalisation are essential.

Such infection can be caused by viruses, bacteria, fungi and parasites. Bacterial infections are the most serious epidemiological and clinical problem because of their incidence, severity of course and increasingly limited possibilities for effective treatment due to the increasing resistance of bacteria to antibiotics.

Regardless of the aetiology, central nervous system infections share a number of common features and are characterised by:

• a mild to fatal course
• sometimes significant difficulties in diagnosis and treatment
• the disease process may involve the cerebrospinal meninges, the brain and the medulla oblongata
• variable clinical presentations: acute, subacute and chronic
• varying incubation periods - varying treatment periods
• the course depends on the biological characteristics of the infected person

photo: ojoimages

Bacterial meningitis and encephalitis Bacterial infections are defined as an inflammatory response to a bacterial infection. Most commonly caused by: Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae. Usually the predominant forms are those resulting from generalised infection, such as septicaemia, which have a mortality rate of up to 40%. Possible neurological complications include hearing loss, cognitive impairment and hydrocephalus.

Clinical picture of bacterial infections

The incubation period ranges from 1 to 5 days. It usually begins with a sudden rise in temperature, chills, vomiting and nausea. This is followed by meningeal symptoms.

95% of patients have at least 2 of the following symptoms:

• headache
• fever
• stiffness of the neck
• apathy, drowsiness, delirium, disturbance of consciousness