Serogroup W135 meningococcal disease in Hajj pilgrims

An outbreak of W135 meningococcal disease occurred in the spring of 2000 am ong pilgrims returning from Saudi Arabia and their contacts. Clinical isola tes from England and Prance were examined and compared with reference strai ns from other countries. Characterisation of isolates by a range of typing methods showed them to be of clonal origin (ET-37) and closely related to o ther meningococci with an established propensity to cause disease clusters. A reappraisal of vaccination strategies for travellers is required.