Bacterial meningitis is considered to be a disease of high interest and one of the issues that public health is often concerned with. Bacterial meningitis is defined as an acute infection of the central nervous system and meninges. The infection is usually caused by Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae type b (Hib) and, less often, beta-hemolytic Streptococcus group A, Gram (–) bacteria and Listeria monocytogenes [1,2].
Neisseria meningitidis, S. pneumoniae and Hib cause more than 75% of all cases of bacterial meningitis and 90% of bacterial meningitis in children . Recently, because of the systematic application of mandatory vaccination, a significant reduction in Hib meningitis cases has been recorded, and a similar reduction in pneumococcal meningitis is expected. Streptococcus pneumoniae is the main cause in adults, followed by N. meningitidis and then L. monocytogenes, which shows an increase in the >50 year age group (and also in neonates) . The less common bacterial causes of meningitis, such as Staphylococcus aureus, Enterobacteriaceae, Streptococcus group b and L. monocytogenes, occur in people with specific susceptibilities, often those who are immunocompromised [1,2].
Infectious agents can be transmitted by direct, person-to-person, contact, including respiratory droplets. Asymptomatic carriers of N. meningitidis, which account for 10% of the general population and up to 25% of juvenile and young adults, are usually the source of transmission .
In Greece, all meningitis cases come under epidemiological surveillance, including meningococcal disease cases (which are the main target of the surveillance) and other bacterial and aseptic meningitis cases.
The Department of Epidemiological Surveillance and Intervention of the Hellenic Center for Disease Control and Prevention (HCDCP) collects data from all meningitis cases from all over the country through the mandatory notification system, by the directorates of public health and the National Reference Center for Meningitis in the National School of Public Health. Additional information regarding the clinical signs and laboratory findings of each case is obtained by communicating with the hospital where each case is hospitalized. In order to take all the necessary preventive measures (chemoprophylaxis when needed and/or immunization) to avoid disease transmission to all individuals who have been in close contact with a patient, it is essential to assign each case to its cause.
Data are recorded and analyzed by week, month, year, prefecture, causative agent, classification, age and gender, in order to detect outbreaks.
Epidemiological data for meningitis (meningococcal disease and bacterial meningitis) in Greece 1998-2011
For the period 1998-2011, 1,952 cases of meningococcal disease were reported to HCDCP; the number of cases ranged between 50 and 263 per year and the mean annual notification rate was 1.29 cases per 100,000 population (Figure 1). During this period, the notification rate consistently decreased.
For the period 1998-2011, the number of cases of meningococcal disease, with known date of birth of the patient, was 1,843 (109 cases with unknown date of birth). The disease appeared to be more frequent among children in the 0-4 year age group, with a mean annual notification rate of 9.1 cases per 100,000 population. The mean annual notification rate decreased progressively in the 5-14 and 15-24 year age groups (3.8 cases and 1.3 cases per 100,000 population, respectively). In other age groups (over 25 years), the mean annual notification rate did not exceed 0.3 cases per 100,000 population (Figure 2).
During 1998-2011, 78% of the meningococcal disease cases were laboratory confirmed. In the same period, 63.7% (1,244) of meningococcal disease cases were serotyped and 1,062 of them (54.4%) were identified as belonging to one of five serotypes (A, B, C, W135 and Y), which are responsible for the majority of invasive meningococcal infections world-wide. In Greece, 61% of meningococcal disease cases are caused by serotype B, followed by serotype C (Figure 3).
During 1998-2011, 117 deaths due to meningococcal disease were recorded, indicating a case fatality rate of 6%. The highest fatality rate was observed in the year 1998 (12.3%) and the lowest fatality rate in the year 2011 (2%). The mean annual mortality rate for the period 1998-2011 was 1.3 deaths per 100,000 population.
Other bacterial non-meningococcal meningitis
For the period 1998-2011, 2,407 cases of bacterial non-meningococcal meningitis were reported to HCDCP; the number of cases ranged between 60 and 250 per year (annual average of total number of cases, 172; total number of cases, 2,407). The mean annual notification rate of other bacterial meningitis for the period 1998-2011 in Greece was 1.6 per 100,000 population (Figure 1). The annual notification rate of bacterial non-meningococcal meningitis, for the period 1998-2008, had increased but for the next 3 years (2009-2011) it decreased (Figure 2).
During 1998-2011, the number of cases of bacterial non- meningococcal meningitis, with known date of birth, totaled 2,164 (243 cases with unknown date of birth). The disease was more frequent among children in the 0-4 year age group and the mean annual notification rate was 7.9 cases per 100,000 population. The mean annual notification rate was progressively reduced in the 5-14 and 15-24 year age groups (2.4 cases and 0.8 cases per 100,000 population, respectively), while in the age group >25 years old the mean annual notification rate showed a progressive increase, with a highest value of 1.5 cases per 100,000 population in the age group >65 years old (Figure 3).
During 1998-2011, 41% of the bacterial non-meningococcal meningitis cases were laboratory confirmed. In the same period, 47.3% (1,139 cases) of the total number of cases with clinical and laboratory findings compatible with bacterial non-meningococcal meningitis were laboratory tested and presented some sort of micro-organism. The main micro-organisms identified are summarized in Table 1; Streptococcus pneumoniae obviously occurred most often.
Table 1: Distribution of bacterial non-meningococcal meningitis by causative agent, Greece, 1998-2011
||No. of cases
Streptococcus spp. (groups A and B)
|Total no. of laboratory confirmed cases
For the period 1998-2011, 114 deaths due to bacterial non-meningococcal meningitis were recorded, indicating a case fatality rate of 4.7%. The highest fatality rate was observed in the year 2000 (7%) and the lowest fatality rate in the year 1998 (1.6%). The mean annual mortality rate for the period 1998-2011 was 0.07 deaths per 100,000 population.
A. Meningococcal disease
In the case of meningococcal disease, the following actions should take place.
- The case must be reported to HCDCP.
- The patient should be isolated for 24 hours after the beginning of the necessary antibiotic therapy .
- The disinfection of schools or any other public places is of no use to prevent disease transmission.
- Quarantine is not applicable .
- Close contact prophylaxis: all individuals who were in close, high-risk contact with the invasive meningococcal disease patient for up to 7 days before the onset of symptoms, have to receive chemoprophylaxis as soon as possible, so long as there are no contraindications [1,4]. The incidence of secondary transmission to close contacts seems to be higher during the first days of initial infection and chemoprophylaxis has to be received 24 hours after the identification of the first case [5,6]. It is useless to receive chemoprophylaxis after 10 days of high-risk contact.
- Rifampicin is the drug of choice [1,2,4,7], given twice daily for 2 days: infants <1 year of age receive 5 mg/kg, infants >1 year of age receive 10 mg/kg and adults receive 600 mg. Pregnant women sound not receive rifampicin. A single intramuscular dose of ceftriaxone, 250 mg for adults and 125 mg for children <15 years, can also be administered, or a single oral dose of ciprofloxacin 500 mg given to adults. These antibiotics can reduce (90–95%) [8–10] and effectively eradicate nasopharyngeal carriage of N. meningitidis.
- A high-risk contact is defined as a close and prolonged ( >8 hours) contact with the initial patient or direct contact with the patient’s saliva or nasopharyngeal secretions, for a period of 7 days preceding the onset of symptoms until 24 hours after the beginning of the antibiotic therapy . High-risk contacts include:
- household contacts
- people living under crowded conditions and those who share the same dormitory
- individuals who were in close contact with the initial patient or the patient’s respiratory secretions (such as close friends and sexual partners, or health care worker contacts who were directly exposed to the patient or the patient’s respiratory secretions, e.g. when carrying out intubation or mouth-to-mouth resuscitation)
- travel contacts seated immediately adjacent to a patient on a flight of more than 8 hours duration\
- children and adults who had contact with the patient within the patient’s educational institution (kindergarten, primary/high school, university).
If a meningococcal disease case occurs in kindergarten, all children and personnel attending the same classroom must receive chemoprophylaxis. If the initial patient presents from a primary or high school, chemoprophylaxis must be given only to close contacts (close friends, adjacent pupils, etc.) of the patient and not to all classmates. Individuals who were involved in the patient’s extracurricular activities (tutorial classes, gyms, etc.) and had close contact should also receive chemoprophylaxis.
Continuous monitoring of the patient’s environment (household, professional, kindergarten, school, etc.) for other suspicious cases is critical. Monitoring for other meningococcal disease cases must be carried out for the period of 7 days preceding the onset of the first patient’s symptoms up to 24 hours after the beginning of contact antibiotic therapy. Onset of fever in a household or other group contact, within 10 days of exposure, is considered a critical point for immediate medical assessment and application of appropriate diagnostic and therapeutic measures.
The available vaccine prevents meningitis caused by the following N. meningitidis serotypes: A, C, Y and W135. A vaccine for the prevention of meningitis caused by N. meningitidis serotype B is not available internationally but it is expected to be within the next few years.
B. Streptococcus pneumoniae
Chemoprophylaxis to close, high-risk contacts of pneumococcal meningitis case is not recommended. Vaccination against S. pneumoniae has proven to be an effective measure for preventing invasive pneumococcal disease.
C. Haemophilus influenzae type b meningitis
If Hib meningitis occurs, children <4 years old who are not fully vaccinated and household adult close contacts should receive chemoprophylaxis. If only one case occurs in the kindergarten, a recommendation of chemoprophylaxis is debatable. If two cases of Hib meningitis occur in a kindergarten in a 60-day period, where children are unvaccinated or not fully vaccinated, then all children and personnel should receive chemoprophylaxis. Rifampicin is the drug of choice, to be given daily at a dose of 20 mg/kg (maximum 600 mg/kg) for 4 days. Vaccination is an effective measure for disease prevention.
1. Heymann DL, ed. Control of communicable diseases manual, 19th edn. American Public Health Association: 2008, pp. 414-426.
2. Tunkel A, Scheld M. Acute meningitis In: Mandell G, Bennett J, Dolin R, eds. Mandell, Douglas, and Bennett’s principles and practice of infectious diseases, 6th edn. Philadelphia, PA: Elsevier/Churchill Livingston, 2005; pp. 1083-1126.
3. Woods CR. Neisseria meningitidis (meningococcus). In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson textbook of pediatrics, 18th edn. Philadelphia, PA: Saunders Elsevier, 2007; pp. 1164-1169.
4. Anderson MS, Glode MP, Smith AL. Meningococcal infections. In: Feigin RD, Cherry JD, Demmler-Harrison GJ, Kaplan SL, eds. Textbook of pediatric infectious diseases, 6th edn. Philadelphia, PA: Saunders Elsevier, 2009; pp. 1350-1366.
5. CDC, Atkinson W, Wolfe S, Hamborsky J, eds. Epidemiology and prevention of vaccine-preventable diseases (the pink book), 12th edn. Washington, DC: Public Health Foundation, 2011.
6. CDC. Prevention and control of meningococcal disease. 1. MMWR 2005;54:1–17.
7. MacNeil J, Cohn A. Meningococcal disease. In: Roush SW, McIntyre L, Baldy LM, eds. CDC. Manual for the surveillance of vaccine-preventable diseases, 5th edn. Atlanta, GA: Centers for Disease Control and Prevention, 2011.
8. Broome CV. The carrier state: Neisseria meningitidis. J Antimicrob Chemother 1986;18(suppl A):25-34.
9. Dworzack DL, Sanders CC, Horowitz EA, et al. Evaluation of single-dose ciprofloxacin in the eradication of Neisseria meningitidis from nasopharyngeal carriers. Antimicrob Agents Chemother 1988;32:1740-1741.
10. Schwartz B, Al-Tobaiqi A, Al-Ruwais A, et al. Comparative efficacy of ceftriaxone and rifampin in eradicating pharyngeal carriage of group A Neisseria meningitidis. Lancet 1988;2:1239-1242.
11. Gardner P. Prevention of meningococcal disease. N Engl J Med 2006;355:1466-1473.
Georgakopoulou Theano, Pipa Efthalia,
Mavraganis Pantelis, Poufta Sofia, Vernardaki Alexandra
Office of Vaccine Preventable and Congenital Diseases
Department for Epidemiological Surveillance and Intervention