- Meningococcal disease is any type of illness caused by Neisseria meningitidis bacteria.
- There are 3 types of vaccine available in the US: Conjugate vaccines (Menactra, Menveo, and MenHibrix), Polysaccharide (Menomune), and Serogroup B vaccines (Bexsero and Trumenba).
- All 11 to 12 year olds should be vaccinated with a conjugate vaccine, with a booster at age 16.
- Those 16 – 23 may be vaccinated with a serogroup B vaccine.
- In certain situations, other children and adults could be recommended to get any of the 3 vaccines.
For Your Patients
From the CDC’s Pink Book:
Meningococcal disease is an acute, potentially severe illness caused by the bacterium Neisseria meningitidis. Neisseria meningitidis is a leading cause of bacterial meningitis and sepsis in the United States. It can also cause focal disease, such as pneumonia and arthritis. N. meningitidis is also a cause of epidemics of meningitis and bacteremia in sub-Saharan Africa. The World Health Organization has estimated that meningococcal disease was the cause of 171,000 deaths worldwide in 2000.
N. meningitidis, or meningococcus, is an aerobic, gram-negative diplococcus, closely related to N. gonorrhoeae, and to several nonpathogenic Neisseria species, such as N. lactamica. The organism has both an inner (cytoplasmic) and an outer membrane, separated by a cell wall. The outer membrane contains several protein structures that enable the bacteria to interact with the host cells as well as perform other functions. The outer membrane is surrounded by a polysaccharide capsule that is necessary for pathogenicity because it helps the bacteria resist phagocytosis and complement-mediated lysis. The outer membrane proteins and the capsular polysaccharide make up the main surface antigens of the organism.
Meningococci are classified by using serologic methods based on the structure of the polysaccharide capsule. Thirteen antigenically and chemically distinct polysaccharide capsules have been described. Some strains, often those found to cause asymptomatic nasopharyngeal carriage, are not groupable and do not have a capsule. Almost all invasive disease is caused by one of five serogroups: A, B, C, W, and Y. The relative importance of each serogroup depends on geographic location, as well as other factors, such as age. For instance, serogroup A has historically been a major cause of disease in sub-Saharan Africa but is rarely isolated in the United States.
Meningococci are transmitted by droplet aerosol or secretions from the nasopharynx of colonized persons. The incubation period of meningococcal disease is 3 to 4 days, with a range of 2 to 10 days.
Meningitis is the most common presentation of invasive meningococcal infection (meningococcal disease) and results from hematogenous dissemination of the organism. Meningeal infection is similar to other forms of acute purulent meningitis, with sudden onset of fever, headache, and stiff neck, often accompanied by other symptoms, such as nausea, vomiting, photophobia (eye sensitivity to light), and altered mental status. Meningococci can be isolated from the blood in up to 75% of persons with meningitis.
Meningococcal sepsis (bloodstream infection or meningococcemia) occurs without meningitis in 5% to 20% of invasive meningococcal infections. This condition is characterized by abrupt onset of fever and a petechial or purpuric rash, often associated with hypotension, shock, acute adrenal hemorrhage, and multiorgan failure. Less common presentations of meningococcal disease include pneumonia (5% to 15% of cases), arthritis (2%), otitis media (1%), and epiglottitis (less than 1%). The case-fatality ratio of meningococcal disease is 10% to 15%, even with appropriate antibiotic therapy. The case-fatality ratio of meningococcemia is up to 40%. As many as 20% of survivors have permanent sequelae, such as hearing loss, neurologic damage, or loss of a limb.
Risk factors for the development of meningococcal disease include deficiencies in the terminal common complement pathway, functional or anatomic asplenia, and underlying chronic disease. Persons with HIV infection are probably at increased risk for meningococcal disease. Certain genetic factors (such as polymorphisms in the genes for mannose-binding lectin and tumor necrosis factor) may also be risk factors. Household crowding, and both active and passive smoking are associated with increased risk. Persons with antecedent viral infection are also at increased risk.