Characterization of Neisseria meningitidis isolates from recent outbreaks in Ethiopia and comparison with those recovered during the epidemic of 1988 to 1989.
The objectives of this study were to collect and characterize epidemic meningococcal isolates from Ethiopia from 2002 to 2003 and to compare them to 21 strains recovered during the previous large epidemic of 1988 to 1989. Ninety-five patients in all age groups with clinical signs of meningitis and a turbid cerebrospinal fluid (CSF) sample were included in the study of isolates from 2002 to 2003. Seventy-one patients (74.7%) were confirmed as having Neisseria meningitidis either by culture (n = 40) or by porA PCR (n = 31) of their CSF. The overall case fatality rate (CFR) was 11.6%; the N. meningitidis-specific CFR was 4.2%. All 40 strains were fully susceptible to all antibiotics tested except sulfonamide, were serotyped as A:4/21:P1.20,9, and belonged to sequence type 7 (ST-7). The strains from 1988 to 1989 were also equally susceptible and were characterized as A:4/21:P1.20,9, but they belonged to ST-5. Antigenic characterization of the strains revealed differences in the repertoire of lipooligosaccharides and Opa proteins between the old and the recent strains. PCR analysis of the nine lgt genes revealed the presence of the lgtAHFG genes in both old and recent strains; lgtB was present in only some of the strains, but no correlation with sequence type was observed. Further analysis showed that in addition to their pgm alleles, the Ethiopian ST-5 and ST-7 strains also differed in their tbpB, opa, fetA, and lgtA genes. The occurrence of new antigenic structures in strains sharing the same serogroup, PorA, and PorB may help explain the replacement of ST-5 by ST-7 in the African meningitis belt.
Norheim
Gunnstein
G
Division of Infectious Disease Control, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, NO-0403 Oslo, Norway.
Rosenqvist
Einar
E
Aseffa
Abraham
A
Yassin
Mohammed Ahmed
MA
Mengistu
Getahun
G
Kassu
Afework
A
Fikremariam
Dereje
D
Tamire
Wegene
W
Høiby
E Arne
EA
Alebel
Tsegaye
T
Berhanu
Degu
D
Merid
Yarid
Y
Harboe
Morten
M
Caugant
Dominique A
DA
D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000235:genetics; D004196:Disease Outbreaks / Q000266:history; D005002:Ethiopia / Q000453:epidemiology; D005260:Female; D005798:Genes, Bacterial; D005838:Genotype; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D007223:Infant; D008297:Male; D008585:Meningitis, Meningococcal / Q000453:epidemiology* / Q000266:history / Q000382:microbiology*; D008875:Middle Aged; D008969:Molecular Sequence Data; D038381:Neisseria meningitidis, Serogroup A / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D010641:Phenotype; D012703:Serotyping; D013997:Time Factors
D004269:DNA, Bacterial