Re-emergence of meningococcal carriage on three-year follow-up of a kibbutz population after whole-community chemoprophylaxis.
A long-term study was conducted to determine the rate of re-emergence of throat carriage of meningococci in a semi-closed kibbutz community after the administration of chemoprophylaxis to all its members. Serotype B:4 was selected as marker organism since it was isolated from a fatal case and was the most frequently occurring strain (80%) among serogroup B isolates, which themselves comprised 54% of all meningococci. The carriage rate among Israeli residents (volunteer workers were analyzed separately) before treatment was 6.6% (49/748) overall, with 4.3% group B strains. Three weeks after treatment, in most cases with rifampicin (whereby three persistently positive persons were retreated with minocycline), no meningococci were recovered. Six months later, 1.9% of a population sample aged < or = 30 years were positive, while before treatment and one and three years later, 9.4%, 8.6% and 4.6% respectively were positive in this age group. Serotype B:4 comprised 81.3% of group B strains before prophylaxis, 5.3% after one year, and 28.6% after three years, thus possibly re-establishing itself as the single dominant serotype. The marked suppression of carriage after mass chemoprophylaxis appeared to last at least six months, with the meningococcal population being re-established within a year.
Block
C
C
Department of Clinical Microbiology, Sheba Medical Center, Tel Hashomer, Israel.
Raz
R
R
Frasch
C E
CE
Ephros
M
M
Greif
Z
Z
Talmon
Y
Y
Rosin
D
D
Bogokowsky
B
B
D000293:Adolescent; D000328:Adult; D000368:Aged; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003140:Communicable Disease Control; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007557:Israel / Q000453:epidemiology; D008297:Male; D008585:Meningitis, Meningococcal / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D008875:Middle Aged; D009345:Neisseria meningitidis / Q000145:classification