Outbreak of W135 meningococcal disease in 2000: not emergence of a new W135 strain but clonal expansion within the electophoretic type-37 complex.
In 2000, >400 cases of disease caused by Neisseria meningitidis serogroup W135 (MenW135), the largest MenW135 outbreak reported to date, occurred worldwide among Hajj pilgrims and their contacts. To elucidate the origin of the outbreak strains and to investigate their relatedness to major clonal groups, genotypic and phenotypic subtyping was performed on 26 MenW135 outbreak-associated isolates and 50 MenW135 isolates collected worldwide from 1970 through 2000. All outbreak-associated isolates were members of a single clone of the hypervirulent electrophoretic type (ET)-37 complex, designated the "(W)ET-37 clone"; 19 additional MenW135 strains were also members of this clone, and the remaining 31 MenW135 strains were clearly distinct. The 2000 MenW135 outbreak was not caused by emergence of a new MenW135 strain but rather by expansion of the (W)ET-37 clone that has been in circulation at least since 1970; the strains most closely related to those causing the 2000 outbreak have been isolated in Algeria, Mali, and The Gambia in the 1990s.
Mayer
Leonard W
LW
Meningitis and Special Pathogens, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30333, USA. lmayer@cdc.gov
Reeves
Michael W
MW
Al-Hamdan
Nasser
N
Sacchi
Claudio T
CT
Taha
Muhamed-Kheir
MK
Ajello
Gloria W
GW
Schmink
Susanna E
SE
Noble
Corie A
CA
Tondella
Maria Lucia C
ML
Whitney
Anne M
AM
Al-Mazrou
Yagoub
Y
Al-Jefri
Mohammed
M
Mishkhis
Amin
A
Sabban
Sameer
S
Caugant
Dominique A
DA
Lingappa
Jairam
J
Rosenstein
Nancy E
NE
Popovic
Tanja
T
D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004196:Disease Outbreaks; D004586:Electrophoresis / Q000379:methods; D005838:Genotype; D014943:Global Health; D006801:Humans; D007514:Islam; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D009345:Neisseria meningitidis / Q000145:classification* / Q000235:genetics* / Q000502:physiology; D010641:Phenotype; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA / Q000379:methods; D014195:Travel; D014774:Virulence / Q000235:genetics
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S