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)
12.3 Investigation
The following information should be collected when investigating suspect or confirmed clusters:
• Core and enhanced notification data (see enhanced form) including
o Risk factors
o Vaccination detail
o Complications
o Microbiological data
o Cluster investigation information including (see Appendix 3)
o Setting and population at risk
• Type of setting (children’s day-care centre, school, residential, ward etc.)
• Number of persons in setting with basic epidemiological description (age, employment,
vaccination status, duration in setting)
• Identification of any highly exposed sub-group e.g. school class
• Close contacts.
Preliminary investigation is required to determine if immediate public health action or further investigation is
required.
Suspect cluster
All suspect clusters should be investigated to confirm or refute the diagnosis.
Confirmed cluster
A confirmed cluster requires immediate public health action.
12.4 Laboratory investigation of cases (and clusters)
Pneumococcal disease should be confirmed and serotype information sought as soon as possible. Early liaison
between the consultant microbiologist, the Department of Public Health, HPSC and National Pneumococcal Typing
Project is recommended.
Additional tests may guide case management or cluster investigation
The following tests are not confirmatory of invasive pneumococcal disease but can support the investigation and
management of suspect cases:
• Sputum - culture
• Nasopharyngeal swabs – culture.
Non culture diagnostic tests
• Urinary antigen tests.
Urinary antigen tests have been used to assist in the clinical diagnosis of invasive pneumococcal disease. However,
the clinical utility of the test is reduced in younger children as the positive predictive value is lower. A positive test
may reflect carriage rather than disease. Therefore, a case with S. pneumoniae antigen detected in urine but with no
positive culture is considered to meet the criteria for ‘possible’ rather than ‘confirmed’ cases (see case definitions).
Positive results, particularly in children < 2 years of age, must be interpreted with caution and in the context of
clinical observations and other investigations.
PCR
PCR- based assays for the detection of specific DNA sequences of S. pneumoniae are available and can be used on
CSF, blood and fluids from normally sterile sites. Positive results in children < 2 years of age must be interpreted with
caution and in the context of clinical observations and other investigations.
Serotyping
Rapid ascertainment of serotype is an important tool to confirm or exclude a suspected cluster, to assess the
relatedness of cases within a cluster and thus inform public health management.
Serotyping is undertaken by the National Pneumococcal Typing Project at the Department of Clinical Microbiology,
RCSI Education and Research Centre, Beaumont Hospital, Dublin.
All pneumococcal isolates should be sent to the National Pneumococcal Typing Project as soon as possible,
particularly when investigating clusters of serious IPD. Upon suspicion of a cluster the microbiologist should liaise
directly with the laboratory.
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