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
Meningitis Introduction to Meningitis Meningitis is inflammation of the layers of tissue that cover the brain and spinal cord (meninges) and of the fluid-filled space between the meninges (subarachnoid space). Meningitis can be... read more : Infection of the tissues covering the brain and spinal cord (meninges)
Sepsis Sepsis and Septic Shock Sepsis is a serious bodywide response to bacteremia or another infection plus malfunction or failure of an essential system in the body. Septic shock is life-threatening low blood pressure ... read more : Infection of the bloodstream (called meningococcemia when caused by meningococci)
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
Children aged 6 months to 3 years (see also Meningitis in Children Meningitis in Children Bacterial meningitis is a serious infection of the layers of tissue covering the brain and spinal cord ( meninges). Bacterial meningitis in older infants and children usually results from bacteria... read more )
Infections are also more common among
Adolescents and young adults (16 to 20 years of age)
College freshmen living in dormitories
Travelers to places where meningococcal disease is common
People living with HIV infection
People whose spleen has been removed or damaged
People who take eculizumab or ravulizumab (drugs that block a component of the immune system called the complement system Complement System One of the body's lines of defense (immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more )
Microbiologists working with meningococci
Close contacts of people who have a meningococcal infection
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 (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.
The bacteria may also be tested to determine which antibiotics are effective (a process called susceptibility testing Testing a Microorganism's Susceptibility and Sensitivity to Antimicrobial Drugs Infectious diseases are caused by microorganisms, such as bacteria, viruses, fungi, and parasites. Doctors suspect an infection based on the person's symptoms, physical examination results,... read more ).
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.
For more information, see also Meningococcal Vaccine Meningococcal Vaccine The meningococcal vaccine protects against infections caused by the bacteria Neisseria meningitidis (meningococci). Meningococcal infections can lead to meningitis (an infection of tissue... read more and the vaccine schedules for children and adults from the Centers for Disease Control and Prevention (CDC).
Meningococcal vaccines protect against specific types (called serogroups) of meningococci that cause most meningococcal disease: serogroups A, B, C, W, and Y.
Two types of meningococcal vaccine Meningococcal Vaccine The meningococcal vaccine protects against infections caused by the bacteria Neisseria meningitidis (meningococci). Meningococcal infections can lead to meningitis (an infection of tissue... read more are available in the United States:
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
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.
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: