Clusters of meningococcal disease in school and preschool settings in England and Wales: what is the risk?
- K L Davison1,
- N Andrews2,
- J M White1,
- M E Ramsay1,
- N S Crowcroft1,
- A A Rushdy3,
- E B Kaczmarski4,
- P N Monk5,
- J M Stuart6
- 1Immunisation Department, HPA Communicable Disease Surveillance Centre, London NW9 5EQ, UK
- 2HPA Communicable Disease Surveillance Centre, London NW9 5EQ, UK
- 3Department of Health, Skipton House, London SE1 6AH, UK
- 4HPA Meningococcal Reference Unit, Withington Hospital, Manchester M20 2LR, UK
- 5Leicestershire Northamptonshire & Rutland Strategic Health Authority, Leicester LE5 4QF, UK
- 6South West, The Wheelhouse, Bond’s Mill, Stonehouse, Gloucestershire GL10 3RF, UK
- Correspondence to:
Ms K L Davison
Immunisation Department, HPA Communicable Disease Surveillance Centre, London NW9 5EQ, UK;
- Accepted 27 June 2003
Aims: To assess the risk of further cases in educational settings in order to inform policy on managing cases and clusters of meningococcal disease.
Methods: Between 1 April 1995 and 31 March 2001, surveillance in preschool and school settings in England and Wales identified 114 clusters of meningococcal disease. Twenty clusters were reported in preschool settings, 43 in primary, 46 in secondary, and five in independent schools. Seventy three clusters (64%) consisted of two or more confirmed cases, of which 30 had two or more serogroup C cases. Following the introduction of the national meningococcal serogroup C vaccination programme in 1999, no serogroup C clusters were observed between April 2000 and March 2001.
Results: The relative risk of further cases in the four weeks after a single case compared with the background rate was raised in all settings, ranging from RR 27.6 (95% CI 15.2 to 39.9) in preschool settings to RR 3.6 (95% CI 2.5 to 4.6) in secondary schools. Absolute risk estimates ranged from 70/100 000 in preschool settings to 3.0/100 000 in secondary schools. The relative risk of clustering was similar for serogroup B and C strains. Most (68%) second cases occurred within seven days of the first case.
Conclusions: Although there was a higher risk of further cases of meningococcal disease in schools and especially in preschool settings, it is not known whether widespread antibiotic use after single cases reduces risk of further cases and if there is a real risk of harm. Evidence of risk reduction is needed to inform public health policy.