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close this bookWHO Recommended Surveillance Standards (WHO; 1999; 157 pages)
View the documentAcknowledgements
View the documentAcronyms
View the documentIntroduction
View the documentNational Coordination of Communicable Disease Surveillance
View the documentExplanatory notes
View the documentSurveillance activities: criteria and WHO Department
View the documentCommunicable disease contacts in Regional Offices
close this folderDiseases
View the documentB20-B21-B22-B23-B24 AIDS
View the documentA22 Anthrax
View the documentA23 Brucellosis
View the documentA00 Cholera
View the documentA81.0 Creutzfeldt-Jakob disease
View the documentA90, A91 Dengue fever (A90) including Dengue haemorrhagic fever (DHF) & Dengue shock syndrome (DSS, A91)
View the documentA36 Diphtheria
View the documentB72 Dracunculiasis (Guinea worm disease)
View the documentA98.3, A98.4 Ebola-Marburg viral diseases
View the documentA83.0 Japanese encephalitis
View the documentB74 Lymphatic filariasis
View the documentB96.3 Haemophilus influenzae type b
View the documentB15-B17 Acute viral hepatitis
View the documentB20-B24 HIV infection
View the documentJ10, J11 Influenza
View the documentA96.2 Lassa fever
View the documentA48.1 Legionellosis
View the documentB55.1, B55.2 Cutaneous leishmaniasis
View the documentLeishmania / HIV co-infections
View the documentB55.0 Visceral leishmaniasis
View the documentA30 Leprosy
View the documentA27 Leptospirosis
View the documentB50-54 Malaria
View the documentB05 Measles
View the documentA39 Meningococcal disease
View the documentA87 Viral meningitis
View the documentB73 Onchocerciasis
View the documentA37.0 Pertussis
View the documentA20 Plague
View the documentA36 Poliomyelitis
View the documentA82 Rabies
View the documentA02.0 Salmonellosis
View the documentB65 Schistosomiasis
View the documentA50-52 Syphilis
View the documentA33 Tetanus, neonatal
View the documentB56-0, B56-1 African trypanosomiasis
View the documentB57 American trypanosomiasis
View the documentA15-A19 Tuberculosis
View the documentA75.3 Scrub typhus
View the documentA95.9 Yellow fever
open this folder and view contentsSyndromes
View the documentAnnex 1 Software free and in the public domain
View the documentAnnex 2 Proposed surveillance definitions
View the documentAnnex 3 Role and use of Geographic Information Systems (GIS) and mapping for epidemiological surveillance

A39 Meningococcal disease

(Meningococcal infection A39 Meningococcal meningitis A39.0 Meningococcemia A39.4)


Meningococcal disease occurs sporadically and in epidemics of meningococcal meningitis; the majority of cases occur in children <5 years. Meningococcal meningitis is the only form of meningitis to cause epidemics. The case-fatality rate is between 5% and 15%. While sub-Saharan Africa is the most severely affected area, epidemic meningococcal disease can affect any country. Meningococcal bivalent A, C and quadrivalent A, C, Y, W135 vaccines are available; immunization of the entire population should be considered to halt epidemics due to A and C serogroup meningocci. In some countries, vaccine is used for close contacts of patients with meningococcal disease due to A, C, Y or W135 serogroups in order to prevent secondary cases. Immunization is also indicated for people travelling to endemic areas. Surveillance is needed to measure and detect epidemics and establish the impact of both epidemic and non-epidemic disease.


Clinical case definition

An illness with sudden onset of fever (>38.5°C rectal or >38.0°C axillary) and one or more of the following:


• neck stiffness
• altered consciousness
• other meningeal sign or petechial or purpural rash

In patients <1 year, suspect meningitis when fever accompanied by bulging fontanelle.

Laboratory criteria for diagnosis


Positive CSF antigen detection or
• Positive culture

Case classification

Suspected: A case that meets the clinical case definition.

Probable: A suspected case as defined above and: Turbid CSF (with or without positive Gram stain) or ongoing epidemic and epidemiological link to a confirmed case

Confirmed: A suspected or probable case with laboratory confirmation.


At peripheral level, individual patient records should be maintained (particularly for contact tracing).

Immediate reporting of all suspected or probable cases from peripheral level to intermediate level.

All cases must be investigated.

Follow-up data on the organism identified and on patient outcome to be sought by the intermediate level.

Routine weekly/monthly reporting of aggregated or case-based data, from intermediate to central level.

A parallel surveillance using reference laboratories for meningococcal diseases may provide detailed microbiological data on serogroup and genotype on a central basis (useful for epidemiological analysis).


Note 1: In countries with limited surveillance infrastructure, 2 approaches to clinical surveillance can be integrated:

A limited amount of data reported from all health sites (e.g., new cases and deaths by week).

More extensive data reported from selected referral health centres.


Note 2: Surveillance of vaccine coverage may be undertaken in areas of mass vaccination or where vaccination for meningococcal disease is part of routine vaccination.



Case-based data for individual patient records and for reporting


• Case classification (suspected/probable/confirmed), unique identifier, age, sex, geographical information, date of onset, date of consultation, vaccination status, treatment received, history of contact with a case, close contacts

Aggregated data for reporting


• By case classification (suspected/probable/confirmed), age group, week, geographical area, and outcome LABORATORY SURVEILLANCE

Isolate-based data for reporting


• Unique identifier, age, sex, date of onset, date of specimen, specimen type, serogroup
• Genotype

Aggregated data for reporting:


• Cases by age group, specimen type, serogroup, genotype



• Incidence by week, month, geographical area and age group

• Use of incidence data to set epidemic thresholds by comparing weekly incidence rates during the same period in 3-5 previous non-epidemic years (flagging)

• Distribution by serogroup and genotype (if available)

• Vaccine coverage (if available)



• Detect and control epidemics of meningococcal disease as early as possible, especially in areas such as developing countries where epidemic meningitis raises particular difficulties

• Strengthen capacity for emergency response to epidemics of meningococcal disease

• Mobilize immunization activities

• Monitor immunization coverage by geographical area to monitor progress and identify areas of poor performance

• Monitor impact of vaccination on disease incidence and vaccine efficacy during epidemics


Deciding when an epidemic is occurring or likely to occur (setting thresholds)

Hyperendemic areas: 15 cases per 100 000 per week averaged over 2 consecutive weeks. Once epidemic disease is detected in a given area, a lower value (say 5 cases/100 000 per week) may be used as a threshold in contiguous areas.

Other situations: 3 to 4-fold increase compared with corresponding time period in previous years, or

Doubling of cases from one week to the next over a period of 3 weeks.


Regional Offices

See Regional Communicable Disease contacts on section "Communicable disease contacts in Regional Offices".

Headquarters: 20 Avenue Appia, CH-1211 Geneva 27, Switzerland

Communicable Diseases Surveillance and Response (CSR)


E-mail: tikhomirove@who.ch / outbreak@who.ch
Tel: (41 22) 791 2656/2850/2111
Fax: (41 22) 791 4878/0746 attn CSR
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