Meningococci

Quick overview:

• Description: Bacteria that cause serious diseases such as meningitis and blood poisoning (sepsis).
• Symptoms : Depending on the disease, initially non-specific signs of illness, skin rash , typical is a rapid worsening of the symptoms
• Transmission: Mostly via coughing, sneezing, speaking (droplet infection), less often directly via smear infection
• Treatment: Rapid intensive medical treatment, antibiotics, sometimes blood pressure-increasing agents (vasopressors)
• Consequences: Despite treatment, complications such as paralysis (in meningitis) and tissue death (in sepsis) occur in 10 to 20 percent of those affected.
• Examinations and diagnosis: physical examination, blood test, blood culture, cerebrospinal fluid examination, test for antibiotic sensitivity of the pathogen (antibiogram)

What is meningococci?

Meningococci (Neisseria meningitidis) are bacteria that sometimes cause serious illnesses. They mainly cause meningitis and blood poisoning (sepsis).

There are a total of 12 different strains (serogroups) of meningococci. They differ in their different structures on the surface of the bacteria. Some of these can make you seriously ill (invasive meningococcal diseases), others cannot (non-invasive meningococcal diseases).

Non-invasive meningococci

The Meiningococcal serogroups E, H, I, K, L and Z do not cause illness. These (non-pathogenic), non-invasive meningococci are found in the nasopharynx of around 10 to 15 percent of all people.

Invasive meningococcal diseases

The disease-causing serogroups include meningococci of groups A, B, C, W (W135), X and Y. If they enter the body, they sometimes cause serious or life-threatening diseases. Doctors then speak of invasive meningococcal diseases. They are among the notifiable diseases.

Invasive meningococcal disease can occur at any age. Babies and toddlers up to the age of two and young people between the ages of 15 and 19 are most commonly affected.

Adults sometimes also become ill, especially if they have a weakened immune system or have contact with meningococcal sufferers or travel to epidemic areas.

Meningococci of serogroups B, C, W and Y are predominantly found in Europe. Large meningococcal epidemics of serogroups A, C, W and X occur predominantly in Africa (meningitis belt) and Asia.

In Germany, around 60 percent of invasive meningococcal diseases can be traced back to meningococci B and 10 to 15 percent each to meningococci C, W and Y. The proportion of diseases caused by meningococci of serogroup C has increased since the introduction (2016) of meningococci C -Vaccinations for children in the first year of life reduced.

Frequency

Invasive meningococcal diseases occur only rarely. In Germany, around 140 people fell ill with meningitis or blood poisoning caused by meningococci in 2022.

Meningococcus: symptoms

People who have nonpathogenic meningococci (serogroups E, H, I, K, L and Z) in their nasopharynx do not show any symptoms.

On the other hand, meningococci of serogroups A, B, C, W, X and Y can cause serious symptoms if they enter the bloodstream from the nasopharynx (invasive meningococcal diseases).

Most commonly, these bacteria cause purulent inflammation of the meninges (bacterial meningitis) or blood poisoning (meningococcal sepsis). Mixed forms also rarely occur.

First signs

Invasive meningococcal disease often begins with symptoms of a respiratory infection. Typically, further symptoms of illness suddenly appear. These include headaches, fever, chills, dizziness and a pronounced feeling of illness.

In infants and babies, early meningitis is often manifested by refusal to eat, pale or mottled skin, a tense or bulging fontanelle, or jumpiness. They are also sensitive to touch. The body may stiffen or become noticeably limp.

Within a few hours, an invasive meningococcal infection can develop into a life-threatening disease in those affected of all ages.

Invasive meningococcal disease can quickly become life-threatening. At the first sign, call an emergency doctor immediately!

Skin rash

Invasive meningococci cause a typical skin rash, especially if blood poisoning is present. Initially, small bleeding occurs in the skin and mucous membrane. They appear as small red or brown dots (petechiae) about the size of a pinhead.

Petechiae differ from other rashes in that when you press a glass on the rash, for example, they do not fade.

As the disease progresses, the petechiae merge to form a bluish, flat rash. If left untreated, these areas of skin can die (necrosis).

Blood poisoning (meningococcal sepsis)

Invasive meningococci enter the bloodstream from the nasopharynx, multiply and spread throughout the body in the blood.

Typical symptoms of blood poisoning are:

• Heart racing, rapid pulse
• rapid breathing, shortness of breath
• Fever
• increasing disturbance of consciousness
• As a result, there is a risk of life-threatening disruptions to the circulation and organ functions

You can read more about the development and typical symptoms of sepsis in our article Blood poisoning [LA1].

Inflammation of the meninges (meningitis)

If meningococci penetrate the brain via the bloodstream, the meninges become inflamed (meningococcal meningitis). This typically results in painful neck stiffness (meningismus). The pain is particularly noticeable when the chin is brought towards the chest. The neck also stiffens.

Other common symptoms of meningitis include nausea, vomiting and impaired consciousness. In addition, the eyes can react hypersensitively to light (photophobia or photophobia).

You can read more about the typical symptoms of meningitis in our article Meningitis[LA2].

Rare meningococcal diseases

Other invasive meningococcal diseases are less common than meningitis and blood poisoning. Examples of this are:

• Pneumonia (pneumonia)
• Inflammation of the heart muscle (myocarditis)
• Inflammation of the inner lining of the heart (endocarditis)
• Inflammation of the heart sac (pericarditis)
• Inflammation of the joints (arthritis)
• Inflammation of the bone marrow (osteomyelitis)

Meningococci: transmission

The transmission of meningococci occurs from person to person. However, the risk of becoming ill is low. Since meningococci only survive for a few seconds outside the body, very close contact is necessary to become infected.

Infection occurs primarily through droplet infection, i.e. via droplets containing bacteria that infected people release into the environment when they sneeze, cough or speak. Other people can breathe them in and become infected.

Meningococcal transmission occurs more rarely through direct contact with infected people via a smear infection. This is the case, for example, if a person comes into direct contact with secretions from the nasopharynx of an infected person. However, transmission via contaminated household items, water or food (indirect smear infection) is not possible.

It usually takes three to four days from infection to the onset of the disease (incubation period), in rarer cases up to 10 days.

How long are infected people contagious?

People infected with meningococcal bacteria are contagious up to seven days before symptoms begin. If they receive appropriate antibiotic therapy, their ability to become infectious drops significantly after 24 hours. The infected people can then no longer pass the pathogens on to other people.

Meningococcal disease: treatment

Invasive meningococcal diseases require treatment in hospital, often in the intensive care unit, as quickly as possible. The earlier therapy begins, the better the chances of recovery. If left untreated, mortality is high.

If invasive meningococcal disease is suspected, the patient is given an antibiotic immediately. Until it is clear which meningococcal serogroup is present, the doctor will administer a so-called broad-spectrum antibiotic (such as cephalosporins or penicillin) as an infusion. It is effective against a variety of pathogens.

In addition, in some cases the administration of corticosteroids (“cortisone”) is necessary. These are strong anti-inflammatory drugs.

If it is clear which meningococci are causing the disease, the patient receives specific antibiotic therapy – i.e. an antibiotic that works specifically against the serogroup found. The treatment usually lasts seven to ten days.

The patient must be isolated until 24 hours after starting antibiotic treatment to protect other people from transmission.

If there is blood poisoning, intensive medical treatment is usually necessary to prevent circulatory failure. To do this, the doctor gives the sick person fluids in the form of infusions and medications that increase blood pressure (vasopressors).

Treatment of contact persons

As a precaution, people who have had close contact with people suffering from meningococci in the last seven days before the onset of the illness also receive an antibiotic (post-exposure prophylaxis).

These include, for example:

• Household contacts
• People who have had direct contact with the patient’s oral or nasal mucosa (via kissing or mouth-to-mouth resuscitation)
• Contact persons in children’s institutions with children under the age of six
• Contact persons in community facilities such as boarding schools, dormitories, barracks
• Airline passengers who have sat next to a patient for more than eight hours

In addition, vaccination (post-exposure vaccination) is recommended for unvaccinated household members and close contacts if the infection was caused by serogroups A, C, W135, Y or B.

You can read more about meningococcal vaccines and who should be vaccinated and when in our article Meningococcal vaccination [LA3].

Meningococcal disease: consequences

With timely treatment with antibiotics, meningococcal diseases can usually be completely cured. However, in around 10 to 20 percent of those affected, the disease leads to complications despite treatment. In some cases, the disease can cause permanent damage.

Possible consequences of meningococcal meningitis:

• Waterhouse-Friderichsen syndrome (blood clotting disorder with kidney failure)
• Paralysis of cranial nerves
• complete paralysis of one side of the body (hemiplegia)
• Seizures
• “Hydrocephalus” (hydrocephalus)
• Limitations of intellect
• Learning difficulties
• Damage to the inner ear
• deafness
• Chronic pain

After sepsis, the following complications are possible:

• Scarring
• Death of tissue (necrosis) in the limbs
• Severe disabilities
• Chronic pain

The mortality rate for bacterial meningitis is approximately 1 percent, for sepsis it is 13 percent, and for sepsis with Waterhouse-Friedrichsen syndrome it is 33 percent.

Diagnosis

In order to diagnose meningococcal disease, several tests are necessary. These usually take place in the hospital.

First, the doctor takes blood from the patient and examines whether it contains meningococci. To do this, he examines the blood under the microscope and also performs a so-called blood culture. An attempt is made to multiply the pathogens contained therein. With further investigations such as PCR, it is possible to clearly identify the cultivated pathogens.

If bacterial meningitis is suspected, a CSF examination follows (CSF = cerebrospinal fluid). To do this, the doctor removes a small amount of this fluid from the spinal canal (lumbar puncture) under local anesthesia. The subsequent examination in the laboratory shows whether meningococci can be found in it.

If meningococci are detectable in blood and/or cerebrospinal fluid, an antibiogram is performed. It shows which antibiotic works specifically against the detected meningococci.

If no meningococci can be detected in the blood or liquor, meningococci may be found in the throat or in the skin lesions.

In the UAE

Whilst the UAE has a robust healthcare system and vaccination programs, sporadic cases of meningococcal infection continue to occur, albeit in small numbers. With cities like Dubai and Abu Dhabi becoming global hubs for travellers, public awareness and surveillance to swiftly identify and contain outbreaks. By fostering a proactive approach to vaccination and public health education, the UAE strives to minimize the impact of meningococci on its population, ensuring the well-being of residents and visitors alike.