Meningococcal disease at the University of Southampton: outbreak investigation

Abstract

In October 1997, an outbreak of meningococcal disease occurred at the University of Southampton. All six cases were first year students living in halls of residence. Microbiological characterization of case and carrier strains, case interviews, and a meningococcal carriage prevalence survey were used to investigate the outbreak. Five cases were due to serogroup C strains, one case was unconfirmed. Serotyping did not distinguish between the strains but gene sequencing permitted identification of two distinct strains in the outbreak. Although none of the cases was known to each other, three had attended the same nightclub one evening 3-4 days before illness. Meningococcal carriage rates in undergraduates were within the range expected (147/587, 25%), but no carriers of outbreak strains were identified in this sample. The findings suggest that in communities with a high degree of social interaction, the introduction of highly virulent meningococcal strains may result in enhanced transmission with clustering of cases.

The natural history of meningococcal carriage and disease

“…Individuals were assumed to be at risk of meningococcal disease at the point of infection and not throughout the entire episode of carriage. This is consistent with observations that most cases occur within a few days of meningococcal acquisition [9,10], although there are documented exceptions to this [11]. A suitable function was derived to describe the age-and serogroup-specific forces of infection (Appendix 1).…”

Resolution of a Meningococcal Disease Outbreak from Whole-Genome Sequence Data with Rapid Web-Based Analysis Methods

“…The approach is demonstrated by a reanalysis of a wellcharacterized meningococcal disease outbreak at the University of Southampton, United Kingdom, that occurred in October 1997 (13,15). This analysis confirmed the conclusions reached by MLST, AGST, and epidemiological analysis, and also provided additional information on the variation of isolates in individual transmission events and the relationship of the isolates to the global variation of the disease-causing clone.…”

Meningococcal disease in a backpackers’ hostel in Scotland: a risk assessment for prophylaxis

“…This totalled six close contacts from the 300 bed hostel. This health protection response was similar to the response in a hall of residence in Southampton in 1997 when the first case in an outbreak was treated as a "single case" and mass prophylaxis was only advised when further cases were notified [8].…”