Meningococcal Diseases

Over 90% of meningococcal infections involve

(See also Bacterial Meningitis in Infants Over 3 Months of Age Bacterial Meningitis in Infants Over 3 Months of Age Bacterial meningitis in infants is a serious infection of the meninges and subarachnoid space. Infants may present with nonspecific symptoms and signs (eg, lethargy, irritability, poor feeding... read more .)

Infections of lungs, joints, respiratory passageways, genitourinary organs, rectum, eyes, endocardium, and pericardium may occur but are less common.

N. meningitidis has been reported to cause urethritis and cervicitis. Recently, the incidence of meningococcal urethritis has been increasing in men who have sex with men and typically follows orogenital contact with an oropharyngeal meningococcal carrier. N. meningitidis colonizes the nasopharynx. N. meningitidis may also cause proctitis Proctitis Proctitis is inflammation of the rectal mucosa, which may result from infection, inflammatory bowel disease, or radiation. Symptoms are rectal discomfort and bleeding. Diagnosis is by proctoscopy... read more , primarily in men who have sex with men.

Meningococci can asymptomatically colonize the nasopharynx (carrier state). Despite documented high rates of colonization (5 to 40% of healthy people), which may be transient, brief, or prolonged, transition to invasive disease is rare (< 1%). A combination of factors is probably responsible for transition from carrier state to invasive disease, which occurs primarily in previously uninfected patients. Carriers (and infected patients) may transmit the organism to people who have direct contact with respiratory secretions or who inhale large-droplet nuclei from a carrier or patient. Nasopharyngeal carriage rates are highest in adolescents and young adults, who serve as reservoirs for transmission of N. meningitidis. Carrier rates rise dramatically during epidemics.

After invading the body, N. meningitidis causes meningitis Acute Bacterial Meningitis Acute bacterial meningitis is rapidly progressive bacterial infection of the meninges and subarachnoid space. Findings typically include headache, fever, and nuchal rigidity. Diagnosis is by... read more and severe bacteremia in children and adults, resulting in profound vascular effects. Infection can rapidly become fulminant. The case-fatality rate is 4 to 6% for meningitis alone, compared with up to 40% for meningococcemia with septic shock Sepsis and Septic Shock Sepsis is a clinical syndrome of life-threatening organ dysfunction caused by a dysregulated response to infection. In septic shock, there is critical reduction in tissue perfusion; acute failure... read more .

Patients with meningitis Acute Bacterial Meningitis Acute bacterial meningitis is rapidly progressive bacterial infection of the meninges and subarachnoid space. Findings typically include headache, fever, and nuchal rigidity. Diagnosis is by... read more frequently report fever, headache, and stiff neck. Other symptoms include nausea, vomiting, photophobia, and lethargy. A maculopapular or hemorrhagic petechial rash often appears soon after disease onset. Meningeal signs are often apparent during physical examination.

Fulminant meningococcemia syndromes include Waterhouse-Friderichsen syndrome (septicemia, profound shock, cutaneous purpura, adrenal hemorrhage), sepsis with multiple organ failure, shock, and disseminated intravascular coagulation. A rare, chronic meningococcemia causes recurrent mild symptoms (mostly joint and cutaneous).

Complications of meningococcal meningitis are common and serious. Of patients who recover, 10 to 20% have serious sequelae, such as permanent hearing loss, intellectual disability, or loss of phalanges or limbs.

Neisseria are small, gram-negative diplococci readily identified with Gram stain and by other standard bacteriologic identification methods. Serologic methods, such as latex agglutination and coagglutination tests, allow rapid presumptive diagnosis of N. meningitidis in blood, cerebrospinal fluid, synovial fluid, and urine. However, both positive and negative results should be confirmed by culture.

PCR testing of cerebrospinal fluid, blood, and other normally sterile sites for N. meningitidis is more sensitive and specific than culture and may be useful when the cerebrospinal fluid Gram stain is negative and when prior antibiotic administration interferes with isolating the organism.

Because meningococci and gonococci appear similar on Gram stain, meningococcal urethritis should be considered if the urethral discharge shows gram-negative diplococci, but the NAAT is negative for gonococci; this situation requires culture of the urethral discharge to identify the Neisseria species causing the infection (see Diseases Characterized by Urethritis and Cervicitis from the CDC).

While awaiting definitive identification of the causal organism, immunocompetent adults suspected of having meningococcal infection are given a third-generation cephalosporin (eg, cefotaxime 2 g IV every 4 to 6 hours, ceftriaxone 2 g IV every 12 hours) or meropenem (2 g IV every 8 hours) plus vancomycin 15 to 20 mg/kg IV every 8 to 12 hours. In immunocompromised patients and patients > 50 years, coverage for Listeria monocytogenes should be considered by adding ampicillin 2 g IV every 4 hours. The fluoroquinolone antibiotic, moxifloxacin, is an alternative in patients allergic to penicillin and cephalosporins.

Once N. meningitidis has been definitively identified, the preferred treatment is one of the following:

In many countries, penicillin G is still the first choice for invasive meningococcal disease. However, because many countries, including the US, have increasing incidence of isolates with reduced susceptibility to penicillin, those countries typically give initial treatment with a third-generation cephalosporin, such as ceftriaxone or cefotaxime. Also, when penicillin is used, follow-up treatment with ceftriaxone, ciprofloxacin, or rifampin is necessary to eliminate nasopharyngeal carriage. There have been reports of isolates resistant to both penicillin and third-generation cephalosporins.

Corticosteroids decrease the incidence of neurologic complications in children and adults with suspected bacterial meningitis due to Haemophilus influenzae type b or S. pneumoniae. The evidence is less clear when N. meningitidis is the cause. However, high-dose corticosteroids worsen the outcome in meningococcal shock without meningitis and should not be used in such cases; however, low-dose corticosteroids can be used in patients with inadequate adrenal function. When corticosteroids are used, they should be given with or before the first dose of antibiotics. Dexamethasone 0.15 mg/kg IV every 6 hours in children and 10 mg IV every 6 hours in adults is given for 4 days.

Meningococcal urethritis is treated with the same drug regimens as gonococcal urethritis. The risk of sexual transmission of meningococcal urethritis is unclear; however, treatment of sex partners can be considered (see Diseases Characterized by Urethritis and Cervicitis from the CDC).

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