On April 6, 2000, the National Meningococcal Reference Center (C.N.R.M.) alerted the DGS to the occurrence in France of two cases of meningococcal infection of serogroup W135 among pilgrims returning from Mecca, and of the emergence of five cases of the same serogroup among pilgrims returning from Mecca in Great Britain. The following day, three additional cases were reported with the same biological and epidemiological characteristics. The C.N.R.M. specified that the isolated strains belonged to the same clone, part of the ET-37 clonal complex. This complex has been responsible for epidemics in Canada and several European countries, the most recent of which was the 1996 epidemic in Spain. On the same day, it was reported that seven cases of this type of infection had been confirmed among pilgrims in the United Kingdom.