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Meningococcal Infections

By

Larry M. Bush

, MD, FACP, Charles E. Schmidt College of Medicine, Florida Atlantic University

Medically Reviewed Sep 2022
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Topic Resources
  • Infection is spread by direct contact with nasal and throat secretions.

  • People feel generally ill and have other often serious symptoms, depending on the area infected.

  • Identifying the bacteria in blood or in a sample taken from infected tissue confirms the diagnosis.

  • Vaccination can help prevent meningococcal infections.

  • Antibiotics and fluids must be given intravenously as soon as possible.

More than 90% of meningococcal infections are

Infections of the lungs, joints, eyes, heart, rectum, and organs of the reproductive and urinary systems may occur but are less common.

In temperate climates, most meningococcal infections occur during winter and spring. Local outbreaks can occur, most often in sub-Saharan Africa from Senegal to Ethiopia. This area, which includes 26 countries, is known as the meningitis belt.

Meningococci reside in the throat and nose of some people without causing symptoms. Such people are called carriers. People often become carriers after outbreaks. However, infection usually occurs in people who have not been exposed previously to meningococci, rather than in carriers. Infection is spread by direct contact with nasal and throat secretions of an infected person (including carriers).

The most commonly infected people are

Infections are also more common among

Other factors that may increase risk of a meningococcal infection include getting a viral infection, living in a crowded household, having a chronic illness, and smoking or being exposed to cigarette smoke (passive smoking).

Outbreaks of meningococcal infection are rare in the United States and account for only a small percentage of cases. Outbreaks tend to occur among people who spend time in or live in close quarters with others, for example, in dormitories, schools, or day care centers, and most often involve people 16 to 23 years of age.

Symptoms of Meningococcal Infections

Most people with a meningococcal infection feel very ill.

Meningitis often causes fever, headache, red rash, and a stiff neck. It can also cause nausea, vomiting, and sensitivity to light.

Infants may have feeding problems and a weak cry, and they may be irritable and sluggish.

Bloodstream infections Bacteremia Bacteremia is the presence of bacteria in the bloodstream. Bacteremia may result from ordinary activities (such as vigorous toothbrushing), dental or medical procedures, or from infections ... read more may cause a rash of red or purple spots. A severe infection may cause dangerously low blood pressure (shock), a tendency to bleed, and dysfunction (failure) of many organs (such as the kidneys and liver).

Rarely, meningococcal infection causes a chronic illness that causes mild, recurring symptoms that mostly involve the joints and skin.

Diagnosis of Meningococcal Infections

  • Examination and culture of samples of blood or other infected tissues, including cerebrospinal fluid obtained by spinal tap

  • Sometimes polymerase chain reaction technique

Doctors suspect meningococcal infection in people who have typical symptoms, particularly if symptoms occur during an outbreak.

To confirm the diagnosis, doctors take samples of blood or other infected tissues or do a spinal tap Spinal Tap Diagnostic procedures may be needed to confirm a diagnosis suggested by the medical history and neurologic examination. Electroencephalography (EEG) is a simple, painless procedure in which... read more Spinal Tap (lumbar puncture) to obtain a sample of the fluid that surrounds the brain and spinal cord (cerebrospinal fluid). The samples are examined under a microscope to check for and identify bacteria. The samples are also sent to a laboratory, where the bacteria can be identified after it is grown (cultured) or other laboratory tests are done.

If the bacteria is difficult to culture or other test results are inconclusive, doctors can do tests to identify pieces of the bacteria’s genetic material. Tests that detect genetic material in microorganisms are called nucleic acid–based tests. Polymerase chain reaction (PCR) is an example of this type of test. The PCR technique is done on samples of cerebrospinal fluid, blood, or other infected tissues. It is used to produce many copies of a gene from the bacteria, making the bacteria much easier to identify.

Sometimes doctors do blood tests that detect antibodies to the bacteria or the capsule that encloses the bacteria. However, the results have to be confirmed by culture.

Prognosis for Meningococcal Infections

Overall, 4 to 6% of people who have meningococcal meningitis die. Up to 40% of people with severe meningococcal bloodstream infections and septic shock die.

Of people who recover from meningococcal meningitis, 10 to 20% have serious complications, such as permanent hearing loss, intellectual disability, or seizures. Complications of bloodstream infections include gangrene of the fingers, toes, or limbs, which may require amputation.

Prevention of Meningococcal Infections

After exposure to meningitis

Family members, medical personnel, and other people who have been in close contact with people who have a meningococcal infection should be given an antibiotic to prevent infection from developing. Antibiotics may be given by mouth or by injection. With most recommended antibiotics, only a single dose or at most 2 days of treatment are needed.

During an outbreak, meningococcal vaccine is also given (in addition to antibiotics) to people in close contact with a person who has a meningococcal infection.

Vaccination

Meningococcal vaccines protect against specific types (called serogroups) of meningococci that cause most meningococcal disease: serogroups A, B, C, W, and Y.

  • MenACWY vaccines: These vaccines protect against meningococcal serogroups A, C, W, and Y. They are part of the routine childhood vaccination schedule and are recommended for all children at age 11 to 12 years, with a booster at age 16 years. These vaccines are also recommended for some infants and for adults who are at increased risk.

  • MenB vaccines: These vaccines protect against meningococcal serogroup B, which is a type of meningitis bacteria that has become common in outbreaks among college students. These vaccines are also recommended for people 10 years of age and older who are at increased risk of meningitis caused by serogroup B.

Treatment of Meningococcal Infections

  • Antibiotics given by vein (intravenously)

  • Fluids given intravenously

  • Possibly corticosteroids

People are usually admitted to an intensive care unit and given antibiotics and fluids intravenously as soon as possible, before doctors get the culture results identifying the organism causing the infection.

If meningococci are confirmed, doctors change the antibiotics to those that tests show are most effective against the bacteria, typically ceftriaxone or penicillin. These drugs are given intravenously.

Corticosteroids (such as dexamethasone) may be given to children and adults who have meningitis. These drugs help prevent brain damage.

More Information

The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

See the following government sites for comprehensive information on everything from updates on outbreaks and risk factors to educational materials and quick links to related topics:

NOTE: This is the Consumer Version. DOCTORS: VIEW PROFESSIONAL VERSION
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