Guidelines for the Early Clinical and Public Health Management of ...

Guidelines for the Early Clinical and Public Health Management of Bacterial Meningitis (including Meningococcal Disease)
Chapter 8.
Management of Clusters/ Outbreaks of Meningococcal
Disease
Key points
• The objective of public health management of outbreaks is to interrupt the transmission of
disease and prevent further cases occurring.
• Clusters/outbreaks may be institution or organisation based or community based.
8.1 Definitions
An institution or organisation based outbreak of meningococcal disease:
Two or more definite cases of meningococcal disease within a four-week period in a group with epidemiological links,
AND where the available microbiological characterisation of the organisms is the same.
A community based outbreak:
Consider intervention if the age specific attack rate is “high”. Although a precise threshold for intervention has not been
set, age-specific attack rates should be calculated. A minimum of four cases of definite meningococcal disease within
a three-month interval, or 40/100,000 in any age group in a three-month period, in a geographical area that makes
epidemiological sense AND where available microbiological characterisation of the organisms is the same. 3
Decisions regarding chemoprophylaxis and vaccination (if appropriate) for a wider group than solely close contacts is
dependent on local risk assessment.
Easy to understand written information should be provided to all individuals regarding control measures taken (or not),
early warning signs and contact details for follow-up advice.
8. 2 Introduction
Outbreaks may occur in the general community or in other settings such as schools and universities. The public health
actions for each of these settings may vary and will depend on the identification of epidemiological links between cases
and identification that the same organism is associated with the outbreak cases.
Outbreaks of invasive meningococcal disease need to be distinguished from increases of sporadic and
epidemiologically unlinked cases. Such increases may occur in the general community or within settings such as
schools and crèches.
When clustering of cases occurs local public health should look for epidemiological links between cases, even if these
are not immediately evident. Identification of such epi-links will inform and direct public health control activities.
The objective of public health management of such outbreaks of invasive meningococcal disease is to interrupt
transmission and prevent further cases. Once an outbreak is either suspected or recognised there is an immediate need
to initiate a coordinated response. Elements of this response include:
• Review available data to determine if there is an outbreak and its extent.
• Identify population at risk and calculation of age-specific and region-specific attack rates.
• Establish an outbreak control team (OCT) and consider a site visit.
• Identify those requiring chemoprophylaxis and/or immunisation.
• Provide information to all contacts and other persons involved.
• Raise awareness and increase surveillance.
• Provide adequate information to health care providers, affected communities, the media and the general
public.
• Monitor and evaluate control measures and prepare final report.
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