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6/15

Is there evidence of recent transmission?

  • Given the serological information, are you any more able to comment on how the meningococcal isolates from cases and contacts relate to each other?

  • Can any conclusions be drawn about transmission between cases and contacts?

  • Given all the information you reviewed in the OCT meeting - who are the at risk group that should be offered chemoprophylaxis? (note that if this cluster was occurring currently, MenC vaccine is available)

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  • Given the serological information, are you any more able to comment on how the meningococcal isolates from cases and contacts relate to each other?
  • The serological results refer to the serogroup, serotype and sero-subtype of the meningococcal isolate. This information comes from testing the isolated bacteria with antibodies capable of binding to specific variants of these components. If the component matches the testing antibody, a type can be assigned.

  • Interpreting serotype and subtype
    • Expression of serotype and sero-subtype can be intermittent, resulting in a nontypeable (NT) result.

    • The serological tests did not fully discriminate the disease isolates, with case 1 characterized as C:2a:NT and cases 3 and 6 as C:NT:P1.5. e.g. No sero-subtype was assigned to the isolate from Case 1 and no serotype was assigned to the isolates from case 3 or case 6.

    The results of the serological tests are compatible with a single strain outbreak but do not provide enough information to prove this was the case.

  • Can any conclusions be drawn about transmission between cases?
  • Given the above results, it is very difficult to draw any conclusions about transmission between cases. We do know that cases 2, 4 and 5 may have shared space (in the nightclub) and time with at least one other of the group 3 or 4 days prior to becoming unwell however we do not have firm time lines for this and there is no isolate from these cases. We do know from the PCR results that cases 4 and 5 were associated with serogroup C meningococci but the additional typing information (serotype and serosubtype) does not allow us to make any further conclusions.

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