Meningococcal Infections

Meningococcus is a well-known and feared bacterium. The mass media often report about a child who survived (or did not survive) meningococcal infection. The full name of this bacterium is Neisseria meningitis. There are several subtypes, which are marked by the letters A, B and C.


Meningococcus usually infects children and adolescents of any age who are weakened and exhausted. Typically, the disease starts the day after a night party – disco, pub, etc. The bacterium lives in upper respiratory tract of many people without causing any symptoms and it can be easily transmitted by exhaled droplets.

Forms of infection

There are several types of meningococcal infection; all of them are potentially life-threatening.

Meningococcal meningitis

This is probably the most famous type of meningococcal infection. The bacteria attack brain meninges causing their inflammation. The disease manifests with neurological symptoms such as sharp headache, stiff neck and inability to bend the head forward, which is accompanied with fever, nausea and vomiting. The paradox is that this dreaded form kills “only” 10% of the patients.

Meningococcal sepsis

Meningococcal sepsis is an extremely serious condition with a mortality rate of about 25% of the affected patients. The term sepsis (“blood poisoning”) means spread of the bacteria throughout the body by blood stream. Sepsis can occur in all bacterial infections and it is related to a strong immune response targeting the bacteria.


Meningococcus causes strong septic condition due to an abundantly produced substance called lipopolysaccharide (LPS). It is released in large quantities into the blood from the decaying bacterial cells (destroyed by our immune system). LPS massively trigger a strong immune response with excessive production of inflammatory substances, which unfortunately threaten our own organism. The condition easily turns into a septic shock with increased permeability of blood vessels resulting in circulatory collapse and heart failure.


In attempt to prevent the worst, blood circulation is reduced to supply the three principal organs important for survival – brain, heart and adrenal glands. Other organs suffer from deficiency of oxygen and nutrients and begin to fail including the liver and kidneys.


The meningococcal sepsis is a rapidly deteriorating condition with drop of blood pressure, increased heart and breathing rate, pallor and decreased production of urine. Total disruption of internal environment includes clotting disorder with skin bleeding looking like a red rash. This little skin hematomas are known as petechiae and they occur typically in the lower extremities. Any young patient with fever and strange reddish rash on the legs should be treated with extreme caution.


In meningococcal sepsis, there are usually present some warning clues – a young man, exhaustion in recent time, flu-like symptoms, reddish spots on the skin. Of course, it is not easy to state the right diagnosis and the meningococcal infection may be very easily mistaken for a banal flu. The bacteria may be cultivated from a blood sample (blood culture).


Meningococcal meningitis may be confirmed by a spinal tap. The obtained cerebrospinal fluid shows signs of bacterial infection (excessive number of white blood cells) and it is also possible to quickly confirm the presence of meningococcus itself. 


The risk of the disease may be lowered by a vaccination. However, the vaccines do not protect us against every subgroup of the bacteria and therefore even vaccinated person can get sick. All people, who have been in close contact with the infected, should receive preventive antibiotics (usually penicillin).


The patients must be hospitalized and treated with high doses of intravenous antibiotics and the therapy should start at the moment of first suspicion. People suffering from meningitis are also usually treated with corticosteroids to prevent brain edema. If the patient is in sepsis, it is necessary to prevent development of a shock condition and organ failure by supplying a large volume of fluid in infusions and ensuring adequate intake of oxygen.


Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources