RATIONALE FOR SURVEILLANCE

Viral meningitis occurs sporadically and also as an epidemic disease. Case-fatality rates are generally low; infection may have potential long-term sequelae in those affected (mostly children), but the disease is rarely severe and recovery is usually complete. The early detection of epidemics through epidemiological surveillance allows for identification of the causal agent and the institution of targeted control measures and effective case management.

RECOMMENDED CASE DEFINITION

Clinical case definition

A case with fever 38.5°C and one or more of the following:

 

• neck stiffness
• severe unexplained headache
• neck pain and 2 or more of the following

 

• photophobia
• nausea
• vomiting
• abdominal pain
• pharyngitis with exudates

For children <2 years of age a case is defined as

 

• A case with fever 38.5°C and one or more of the following

 

• irritability
• bulging fontanelle

Laboratory criteria for confirmation

The specific virus confirmed on cell culture.

Case classification

Suspected: A case that meets the clinical case definition.

Suspected: A suspected case with one or more of the following:

 

• normal CSF glucose and normal or mild increase in CSF protein (>50mg/dl), moderate increase CSF cells (<500/mm³) and lymphocyte predominance (>50%)

• CSF Positive for viral genomic sequences using PCR (Polymerase Chain Reaction)

• Epidemiological link to a confirmed case

Confirmed: A suspected or probable case with laboratory confirmation.

RECOMMENDED TYPES OF SURVEILLANCE

At peripheral level individual patient records should be maintained.

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

All cases must be investigated. Follow-up data on identified organism and patient outcome to be sought by the intermediate and central level.

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

A parallel surveillance using reference laboratories for viral diseases may provide more detailed virological data on specific causal agents on a national basis; these are very useful for epidemiological analysis.

RECOMMENDED MINIMUM DATA ELEMENTS

CLINICAL SURVEILLANCE

Case-based data for individual patient record and for reporting

 

• Case classification (suspect/probable/confirmed), unique identifier, age, sex, geographical information, date of onset, date of consultation, treatment received

Aggregated data for reporting

 

• Case by case classification (suspect/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, organism identified

Aggregated data for reporting

 

• Cases by age group, specimen type, organism identified

RECOMMENDED DATA ANALYSES, PRESENTATION, REPORTS

Incidence by week, month, geographical area, age group, outcome.

PRINCIPAL USES OF DATA FOR DECISION-MAKING

 

• To detect and control epidemics of viral meningitis as early as possible
• To strengthen the capacity for emergency response to epidemics of viral meningitis

SPECIAL ASPECTS

None.

CONTACT

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