Meningococcal Disease

Description

Meningococcal disease is an acute bacterial disease characterised by sudden onset with fever; intense headache; nausea and often vomiting; stiff neck; and, frequently, a petechial rash with pink macules. Formerly, the case-fatality ratio exceeded 50%, but early diagnosis, modern therapy, and supportive measures have lowered the case-fatality ratio to about 10%. Among survivors, 11%-19% have long-term sequelae, including hearing loss, neurologic disability, or loss of a limb. Up to 10% of populations in countries with endemic disease carry the bacteria (Neisseria meningitidis) asymptomatically in their nose and throat.

Meningococci are classified into serogroups based on the composition of the capsular polysaccharide. Five major meningococcal serogroups associated with disease are A, B, C, Y and W-135. In the past 30 years, meningococci serogroups B and C have been responsible for most disease in the Americas and Europe. Serogroup A meningococci and, to a lesser extent, serogroup C, account for most meningococcal disease cases in Africa and some areas in Asia. During the past years, serogroup Y has emerged as a cause of disease in Northern America, and serogroup W-135 has been associated with meningococcal disease epidemics in Saudi Arabia and Burkina Faso.

Occurrence

In the sub-Saharan African "meningitis belt," which extends from Mali to Ethiopia, peaks of serogroup A meningococcal disease occur regularly during the dry season (December through June). In addition, major epidemics occur every 8-12 years (see Map 4-9). In 2000, a serogroup W-135 epidemic occurred in Saudi Arabia in association with the Hajj pilgrimage. Cases also occurred in returning pilgrims and their families, including several cases in the United States. In 2002, a major meningococcal disease epidemic occurred in Burkina Faso caused by serogroup W-135. In 2003 and 2004, serogroup W-135 has been detected in several African countries, but it has not caused major epidemics. Meningococcal disease continues to cause epidemics outside the meningitis belt, including recent epidemics in the Great Lakes of Africa.

Map 4-9. Areas with frequent epidemics of meningococcal meningitis

Map 4-9. Areas with frequent epidemics of meningococcal meningitis

Risk for Travellers

Travellers to sub-Saharan Africa may be at risk for meningococcal disease. Travellers to the meningitis belt during the dry season should be advised to receive meningococcal vaccine. Prompted by a serogroup A meningococcal disease outbreak associated with the 1987 Hajj, Saudi Arabia requires that Hajj and Umrah visitors have a certificate of vaccination against meningococcal disease before entering; however, the vaccine formulation varies by country.

Clinical Presentation

Sudden onset of fever, intense headache, stiffness of the neck, nausea, and often vomiting are common symptoms of meningitis in anyone over the age of 2 years. These symptoms can develop over several hours, or they may take 1-2 days. Other symptoms may include photophobia and an altered mental status. In infants, a slower onset of symptoms may occur with nonspecific symptoms, and neck stiffness may be absent.

Early diagnosis and treatment are very important. If symptoms occur, the patient should see a doctor immediately. The diagnosis is usually made by growing bacteria collected from cerebrospinal fluid (CSF) or by detection of the meningococcal antigen through latex agglutination in fresh CSF. Neisseria meningitidis can also be identified in blood cultures. The signs and symptoms of meningococcal meningitis are similar to those of other causes of bacterial meningitis, such as Haemophilus influenzae and Streptococcus pneumoniae. Identification of the type of bacteria responsible is important for selection of correct antibiotics.

Signs and symptoms of meningitis

High fever, headache, and stiff neck are common symptoms of meningitis in anyone over the age of 2 years. These symptoms can develop over several hours, or they may take 1 to 2 days. Other symptoms may include nausea, vomiting, discomfort looking into bright lights, confusion, and sleepiness. In newborns and small infants, the classic symptoms of fever, headache, and neck stiffness may be absent or difficult to detect, and the infant may only appear slow or inactive, or be irritable, have vomiting, or be feeding poorly. As the disease progresses, patients of any age may have seizures.

Prevention

Vaccination against meningococcal disease is not a requirement for entry into any country except Saudi Arabia, for travellers to Mecca during the annual Hajj and Umrah pilgrimage. Vaccination is advised for travellers to countries recognised as having epidemic meningococcal disease caused by a vaccine-preventable serogroup (i.e., A, C, Y, and/or W-135) during December through June. Advisories for travellers to other countries will be issued when epidemics of meningococcal disease caused by vaccine-preventable serogroups are recognised. (See the CDC Travellers' Health website at http://www.cdc.gov/travel/outbreaks.htm.) Vaccines may benefit travellers to and persons residing in countries in which meningococcal disease is hyperendemic or epidemic, particularly if contact with the local population will be prolonged. Vaccines are also recommended for high risk-travellers who have certain medical conditions, particularly persons who have deficiencies in the terminal common complement pathway (C3, C5-9) and those who have anatomic or functional asplenia.

Serogroup A is the most common cause of epidemics outside the United States, but serogroups C and B can also cause epidemic disease. As of October 1, 2004, only one formulation of the meningococcal polysaccharide vaccine is available in the United States: quadrivalent A/C/Y/W-135 vaccine (Table 4-12). The vaccine, which is available in single- and 10-dose vials, is distributed in the United States by Sanofi-Pasteur. Approximately 7-10 days are required following vaccination for development of protective levels of antimeningococcal antibodies. No vaccine is currently available to offer protection against serogroup B. Meningococcal vaccines are chemically defined antigens consisting of purified bacterial capsular polysaccharides, each inducing serogroup-specific immunity. In general, use of meningococcal polysaccharide vaccine should be restricted to persons at least 2 years of age; however, children as young as 3 months of age may be vaccinated to elicit short-term protection against serogroup A meningococcal disease. The group Y and W-135 polysaccharides have been shown to be safe and immunogenic in adults; however, the response of infants to these polysaccharides is unknown.

New meningococcal conjugate vaccines have recently been developed. These vaccines are expected to be highly efficacious in young children, confer long-term protection, and provide herd immunity by reducing carriage and disease transmission. Serogroup C polysaccharide conjugate vaccines are already licensed for use in infants and children in Europe and Canada. Studies in the United Kingdom (UK) have reported that these vaccines are safe and immunogenic in infants and children and can decrease transmission, thus protecting unvaccinated individuals by inducing herd immunity. In 2000, after introduction of the vaccine in the UK, the vaccine was shown to be highly efficacious and resulted in a dramatic decline in the number of serogroup C meningococcal disease cases. The vaccine also reduced carriage of serogroup C meningococci among young adults by 67%.

A new quadrivalent A/C/Y/W-135 meningococcal conjugate vaccine has been licensed in the United States early in 2005 for use among persons 11-55 years of age. Pre-licensure data on the new quadrivalent conjugate vaccine have shown that the vaccine appears to be safe and immunogenic and is expected to offer a duration of protection longer than polysaccharide vaccines. CDC's Advisory Committee on Immunisation Practices (ACIP) is developing recommendations for use of this vaccine, including its use among travellers 11-55 years of age. The quadrivalent A/C/Y/W-135 polysaccharide vaccine will likely remain acceptable for ages 11-55, as well as for persons ages 2-11 and >55 years of age.

Table 4-12. Meningococcal vaccine

Type of Vaccine Dose Comments
Quadrivalent A, C, Y, W-135, for subcutaneous injection 0.5 mL Duration of immunity is unknown, but appears to be at least 3 years in those greater than or equal to4 years of age. Revaccination after 2-3 years should be considered for children first vaccinated at <4 years of age who continue to be at high risk.

Antibiotic chemoprophylaxis among close contacts of a meningitis case may be recommended for control of secondary disease in the United States. Antimicrobial regimens for prophylaxis include rifampin, ciprofloxacin and ceftriaxone, although rifampin is not recommended for pregnant women. Antimicrobial chemoprophylaxis should be considered for passengers who have had direct contact with respiratory secretions from the index patient, and passengers seated directly next to the index patient on prolonged flights (>8 hours) (http://www.cdc.gov/travel/menin-guidelines.htm). A study in 2001 among U.S. Hajj pilgrims found that pathogenic meningococcal nasopharyngeal carriage was uncommon in this vaccinated population; CDC does not currently recommend antimicrobial chemoprophylaxis for returning pilgrims.

Adverse Reactions

Adverse reactions to meningococcal vaccine are infrequent and mild, consisting principally of localized erythema that lasts 1-2 days. Transient fever may develop in up to 2% of infants after vaccination. Data reported from prelicensure clinical trials from the A/C/Y/W-135 meningococcal conjugate vaccine show generally few mild adverse events, such as pain and redness at the injection site for 1-2 days.

Precautions and Contraindications

Studies of the meningococcal polysaccharide vaccine during pregnancy have not documented adverse events among either women or neonates (less than or equal to1 month of age). Based on data from studies involving the use of meningococcal vaccines and other polysaccharide vaccines administered during pregnancy, altering meningococcal vaccination recommendations during pregnancy is unnecessary.

Treatment

Meningococcal disease is potentially fatal and should always be viewed as a medical emergency. Admission to a hospital or health center is necessary. Standard and droplet precautions should be considered to reduce the risk of transmission of disease during hospitalization (http://www.cdc.gov/ncidod/hip/ISOLAT/isopart2.htm). Bacterial meningitis can be treated with a number of effective antibiotics. However, treatment must be started early in the course of the disease, as soon as possible after the lumbar puncture has been done (if started before, it may be difficult to grow the bacteria from the spinal fluid and thus confirm the diagnosis). Appropriate antibiotic treatment (including penicillin G, ampicillin, and third generation cephalosporins) of most common types of bacterial meningitis should reduce the risk of dying from meningitis to below 15%, although the risk is higher among the elderly.

Under epidemic conditions in Africa, the World Health Organization (WHO) recommends the use of intravenous chloramphenicol, ceftriaxone, or amipicillin. In situations with very limited resources, a single intramuscular dose of an oily suspension of chloramphenicol can be used to treat epidemic meningococcal meningitis. Further details of that treatment can be found at the following website: http://www.who.int/mediacentre/factsheets/fs141/en/.

Bibliography
  • American Academy of Paediatrics. Meningococcal infections. In: Pickering LK, editor. Red book: 2003 report of the Committee on Infectious Disease. 26th ed. Elk Grove Village, IL: American Academy of Paediatrics; 2003. p. 430-6.
  • CDC. Prevention and control of meningococcal disease: recommendations of the Advisory Committee on Immunisation Practices (ACIP). MMWR Recomm Rep. 2000;49(RR-7):1-10.
  • CDC. Risk for meningococcal disease associated with the Hajj 2001. MMWR. 2001;50:97-8.
  • Dull P, Abdelwahab J, Sacchi CT, et al. Serogroup W-135 Neisseria meningitidis carriage among US travellers to the 2001 Hajj. J Infect Dis. In press 2004.
  • Greenwood B. Meningococcal meningitis in Africa. Trans R Soc Trop Med Hyg. 1999;93:341-53.
  • Lingappa JR, Rosenstein N, Zell ER, et al. Surveillance for meningococcal disease and strategies for use of conjugate meningococcal vaccines in the United States. Vaccine. 2001;19:4566-75.
  • Ramsay ME, Andrews N, Kaczmarski EB, et al. Efficacy of meningococcal serogroup C conjugate vaccine in teenagers and toddlers in England. Lancet. 2001; 357:195-6.
  • Rosenstein NE, Perkins BA, Stephens DS, et al. Meningococcal disease. N Engl J Med. 2001;344:1378-88.
  • Rosenstein NE, Perkins BA, Stephens DS, et al. The changing epidemiology of meningococcal disease in the United States, 1992-1996. J Infect Dis. 1999;180:1894-901.

-Kristin Uhde, Nancy Rosenstein Montse Soriano-Gabarró

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